What Does It Mean to Be Fat Adapted or Keto Adapted?

fat adaptedWhen describing someone that has successfully made the transition to a Primal or Keto way of eating I often refer to them as “fat-adapted” or as “fat-burning beasts”. But what exactly does it mean to be fat-adapted? How can you tell if you’re fat-adapted or still a sugar-burner?

As I’ve mentioned before, fat-adaptation is the normal, preferred metabolic state of the human animal. It’s nothing special. It’s just how we’re meant to fuel ourselves. That’s actually why we have all this fat on our bodies – turns out it’s a pretty reliable source of energy.

Here’s what you need to know about the benefits of becoming fat adapted, or keto adapted, and why it works with your biology.

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Are Being in Ketosis and Being Fat Adapted the Same Thing?

Fat-adaption does not necessarily mean you’re in ketosis all the time. Ketosis ketosis describes the use of fat-derived ketone bodies by tissues (like parts of the brain) that normally use glucose. That happens after you’ve depleted your glucose stores, and your body starts producing ketones for energy. When you’re in ketosis, you can usually detect ketones in your bloodstream.

Fat-adaption describes the ability to burn both fat (through beta-oxidation) and glucose (through glycolysis).

The Disadvantages of Primarily Burning Sugar for Energy

To understand what it means to be fat adapted, it’s useful examine what it means to depend on sugar for energy.

It Is More Difficult to Access Stored Fat for Energy When You’re Dependent on Sugar

What that means is, when your body is primarily looking for sugar for fuel, your skeletal muscle doesn’t as readily oxidize fat for energy.

What happens when a sugar-burner goes two, three, four hours without food, or skips a whole entire meal? They get ravenously hungry. A sugar-burner’s adipose (fat) tissue even releases a bunch of fatty acids 4-6 hours after eating and during fasting, because as far as your biology is concerned, your muscles should be able to oxidize them. After all, we evolved to rely on beta oxidation of fat for the bulk of our energy needs. Once your blood sugar is all used up (which happens really quickly), hunger sets in, and your hand reaches into the chip bag yet again.

A Sugar Burner Doesn’t Readily Access Dietary Fat for Energy

As a result, more dietary fat is stored than burned. Unfortunately for them, they’re likely to end up gaining lots of body fat. As we know, a low ratio of fat to carbohydrate oxidation is a strong predictor of future weight gain.1

Sugar Stores Deplete Quickly And Need to Be Replenished Often

A sugar-burner depends on a perpetually-fleeting source of energy. Glucose is nice to burn when you need it, but you can’t really store very much of it on your person (unless you count snacks in pockets). Even a 160 pound person who’s visibly lean at 12% body fat still has 19.2 pounds of animal fat on hand for oxidation, while our ability to store glucose as muscle and liver glycogen (stored glucose) are limited to about 500 grams (depending on the size of the liver and amount of muscle you’re sporting).2 If you’re unable to effectively beta oxidize fat (as sugar-burners often are), you’d better have some quick snack options on hand.

Sugar Burners Use Stored Glucose Quickly During Exercise

Depending on the nature of the physical activity, glycogen burning could be perfectly desirable and expected, but it’s precious, valuable stuff. If you’re able to power your efforts with fat for as long as possible, that gives you more glycogen – more rocket fuel for later, intenser efforts (like climbing a hill or grabbing that fourth quarter offensive rebound or running from a predator). Sugar-burners waste their glycogen on efforts that fat should be able to power.

The Benefits of Being Fat Adapted

There are some compelling advantages to being fat adapted or keto adapted, which may move you to make the switch if you haven’t already.

People Who are Fat Adapted Often See Improved Insulin Sensitivity

A ketogenic diet “tells” your body that no or very little glucose is available in the environment. The result? “Impaired” glucose tolerance 3 and “physiological” insulin resistance, which sound like negatives but are actually necessary to spare what little glucose exists for use in the brain. On the other hand, a well-constructed, lower-carb (but not full-blown ketogenic) Primal way of eating that leads to weight loss generally improves insulin sensitivity.4

Being Fat Adapted Means You Go Longer Between Meals

A fat-burning beast can effectively burn stored fat for energy throughout the day. If you are fat adapted, chances are, you can handle missing meals and are able to go hours without getting ravenous and cranky (or craving carbs).

You Can Better Utilize the Fat You Eat for Energy

A fat-burning beast is able to effectively oxidize dietary fat for energy. If you’re adapted, your post-prandial (after mealtime) fat oxidation will be increased, and less dietary fat will be stored in adipose tissue.

When You’re Keto Adapted, You Always Have a Fuel Source

A fat-burning beast has plenty of accessible energy available in the form of body fat, even if he or she is lean. If you’re adapted, the genes associated with lipid metabolism will be upregulated in your skeletal muscles.5 You will essentially reprogram your body.

You Can Burn Fat While Exercising

A fat-burning beast can rely more on fat for energy during exercise, sparing glycogen for when he or she really needs it. As I’ve discussed before, being able to mobilize and oxidize stored fat during exercise can reduce an athlete’s reliance on glycogen. This is the classic “train low, race high” phenomenon, and it can improve performance, save the glycogen for the truly intense segments of a session, and burn more body fat.6 If you can handle exercising without having to carb-load, you’re probably fat-adapted. If you can workout effectively in a fasted state, you’re definitely fat-adapted.

You Can Still Burn Glucose When Fat Adapted

It’s not that the fat-burning beast can’t burn glucose – because glucose is toxic in the blood, we’ll always preferentially burn it, store it, or otherwise “handle” it – it’s that we do not depend on it. I’d even suggest that true fat-adaptation will allow someone to eat a higher carb meal or day without derailing the train. Once the fat-burning machinery has been established and programmed, you should be able to effortlessly switch between fuel sources as needed.

A fat-burning beast will be able to burn glucose when necessary or available, whereas the opposite cannot be said for a sugar-burner. Ultimately, fat-adaption means metabolic flexibility. It means that a fat-burning beast will be able to handle some carbs along with some fat. When you’re fat adapted, you will be able to empty glycogen stores through intense exercise, refill those stores, burn whatever dietary fat isn’t stored, and then easily access and oxidize the fat that is stored when it’s needed.

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How Do You Know if You’re Fat Adapted or Keto Adapted?

There’s really no “fat-adaptation home test kit.” I suppose you could test your respiratory quotient, which is the ratio of carbon dioxide you produce to oxygen you consume. An RQ of 1+ indicates full glucose-burning; an RQ of 0.7 indicates full fat-burning. Somewhere around 0.8 would probably mean you’re fairly well fat-adapted, while something closer to 1 probably means you’re closer to a sugar-burner. The obese have higher RQs. Diabetics have higher RQs.7 Nighttime eaters have higher RQs (and lower lipid oxidation).8 What do these groups all have in common? Lower satiety, insistent hunger, impaired beta-oxidation of fat, increased carb cravings and intake – all hallmarks of the sugar-burner.

It’d be great if you could monitor the efficiency of your mitochondria, including the waste products produced by their ATP manufacturing, perhaps with a really, really powerful microscope, but you’d have to know what you were looking for.

No, there’s no test to take, no simple thing to measure, no one number to track, no lab to order from your doctor. To find out if you’re fat-adapted, the most effective way is to ask yourself a few basic questions:

  • Can you go three hours without eating? Is skipping a meal an exercise in futility and misery?
  • Do you enjoy steady, even energy throughout the day? Are midday naps pleasurable indulgences, rather than necessary staples?
  • Can you exercise without carb-loading?
  • Have the headaches and brain fuzziness passed?

Yes? Then you’re probably fat-adapted. Welcome to the human metabolism you were wired for!

That’s it for today, folks. Send along any questions or comments that you have. I’d love to hear from you guys.

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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450 thoughts on “What Does It Mean to Be Fat Adapted or Keto Adapted?”

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  1. You should do a follow-up entitled ‘you might be fat-adapted if…’ à la Jeff Foxworthy. I see a night job in standup ancestral health comedy in your future!

    1. Mark does well in front of the camera already! If you’ve seen him on news programs and what not. Great idea haha

    2. Aren’t ketones produced as a by product of fat oxidation? So if you are a fat burner, you will produce ketones. The better you are at burning fat, the more ketones you produce and, conversely, the less stored fat you burn, the fewer ketones you produce. It would seem, therefore, that if you want to lose weight, you should lower insulin levels to release TG from adipose tissue. Blood ketone levels are the best way of measuring good how good you are at burning fati.

      1. That is a complicated answer because a good fat burning body will utilize more ketones without dumping them in to urine. personally I don’t focus on how dark my Ketosticks get. As long as you are registering ketones at all is all you need to know.

        I eat -80% fat 15% protien and 5% carbs while in weightloss mode. Once I hit my goal weight I will change this ratio to roughly 65%fat 30%protien and 5%carbs

        1. When will I start to feel all that crazy energy? I’ve been doing this for 13 days very new to it all! I am 5’6 started at 154 goal weight 130, I’ve lost 6.2 lbs I understand that is water weight, I run on the treadmill, and I do about half hour strength training every other day but I feel drained

          1. Hey Michelle! I know this is a 2 month old post, but wondering how the switch to fat-burning ended up for you??

          2. Michelle, are you keeping your training intensity at a level that allows you to breathe through your nose like Mark suggests? If you’re training at a much higher intensity level it could be causing you to rely more on glycogen. If that’s not being replenished adequately through dietary carb intake it could be causing you to feel run down.

          3. I’ve readjusted after my vacation, and started dropping weiggt again, started doing Yoga daily! My spirits and energy is back where it should be!

          4. Make sure you’re getting PLENTY of salt! Like, way more than you probably are used to.

          5. If you’ve only been on this 13 days, you should not be doing any type of exercise until you start to feel more energized. You put yourself at risk of quitting due to the way you feel. That’s what I’ve read about being fat adapted, doing keto/carnivore. You need to give yourself the time to switch from being a sugar burner to a fat burner; that means no exercise, take it easy until you feel you are able to because you are full of energy.

  2. I don’t think I’m fully fat adapted yet.

    I start to feel hungry about four – five hours after a meal, although not ravenous ever. I’ve managed to skip the carb cravings (unless you count aged cheese cravings).

    I have a lot more energy than previously, but in my cool, quiet, dimly lit office, I start to feel sleepy around 3 – 4 in afternoon. If I’m actually busy or somewhere else, I don’t feel tired.

    Even at my worst, I never carb loaded to exercise, although I still dehydrate faster than ideal.

    Brain fuzziness is gone! Headaches are all work-related (seriously).

    I think I’ll get there soon. Or at least, I hope so!!

    1. Rachel, if you keep getting sleepy in the afternoon, I would try moving outside for a little bit and experimenting with that. Sometimes just standing up and walking outside for awhile can really give you a great pick-me-up

      1. Sounds like a good idea, but my office set up doesn’t allow for going outside very often. I’ll sometimes do a circuit of the building interior. That helps.

        1. Start taking smoke breaks without cigarettes. The smokers shouldn’t have perks that you miss just because you are health-conscious.

        2. Haha. Smokers don’t get breaks where I work. Our grounds went totally smoker free in January.

      2. Try drinking water with squeezed lemon. It is a very effective perk me up!

    2. for the afternoon slump, consider drinking a glass of H2O. In many cases it is because you are dehydrated that you lose energy in the afternoon. There is also an idea of having a good healthy snack in the PM. I eat 4-5 times a day – smaller meals. That keeps energy consistent through the day.

      1. The idea of energy being consistent is conventional wisdom/sugar burner mentality. If you are truly fat adapted, you shouldn’t feel the need for a snack. Up your protein and fat content during the 1-3 meals you eat each day and those cravings for a snack will go away.

      2. Whatever works each of us, but the 5 small meal a day thing is part of the old CW for people who eat “low fat” and have ‘good carbs’ in each meal. As Mark says in this post, being fat-adapted means having consistent energy without having to be eating all day.

    3. My totally non-expert opinion on this is that it has more to do with the conditions in the office. Cool, quiet, and dim sounds like twilight, and it may be fooling your body into thinking it’s getting towards bedtime.

      I’m in a similar situation, and was definitely feeling the afternoon slump. So, I got a desk lamp and put a strong “natural light” bulb in it. The addition of the bright, warm light seems to help.

    4. Maybe also this is your dinner time. Four or five hours might just be your body saying time to eat again. I sometimes eat dinner at around three or four and that’s it for the day as far as food. I live in Germany so we eat the American ‘dinner’ at lunch. Dinner tends to be something simple like salad, crackers and deli meat and cheese, cucumbers, tomatoes, bell peppers, soup warm or cold depending on the weather.


    5. Rachel, Have you ever had your vit D3 tested? If you are indoors a lot, and especially if you live in North East, you could be deficient. (I take a supp and it helps me)

    6. Why assume there is something wrong with getting sleepy in the afternoon. Maybe you just need a nap …

  3. After 12 months being Primal and having shed 18 lbs, now down to 149lbs I think I pass the fat-adapted test, but there are two things that worry me:

    1. A year in and the smell of fresh baked bread leaves me like a shark in blood infested water – why is this still happening? It’s almost like fighting an addiction! I “got over” everything else I kicked out of my diet in a week

    2. I can go for hours without eating but have noticed that when I do get hungry there is something in me that wants to hit the carbs…..I don’t and reach for a handful of almonds and raisins instead…..it’s almost like being “caught out” by something in the back of the brain

    Overall I’m so glad I’ve made this additional step in my life. I could never imagine how an already fit and agile guy has gone now to a new and different level.

    Thanks Mark


    1. I think fresh baked bread is just one of those smells that is soooooo heavenly that you never get over it! But I’ll be honest – About 2 weeks ago (I’m 10 months into primal) I gave into that craving after smelling some rolls at a local shop that I used to eat at all the time. I was so excited, and willing to just splurge that one time – and it wasn’t worth it. The taste wasn’t as good as I remembered. I think my taste buds have actually changed. I used to LOVE them..and it was utter disappointment. I should’ve just ignored the call and stuck with the wonderful aroma and sweet memory. Oh, well…clearly, I’m better off without.

      1. When I get bread cravings, I will indulge in a slice or two of a fresh loaf of italian bread, sliced at home and dipped in some great olive or avocado oil and balsamic, and make a little snack (maybe with some green olives or cheese), and I enjoy the hell out of it! Keeps me off bread with zero cravings for weeks at a time.

        1. My friend was told when selling her country styled cottage to borrow a bread maker and time it to finish right over the open inspection. Worked too! Very psychological, smells are one of the biggest triggers. I don’t buy it or keep it at home, never was a huge bread eater anyway (phew!)

        2. When great-smelling bread is in front of me, I just take about a quarter sized piece (usually from the crust) and eat it with equal parts or more of butter. I might do that twice at most. Gets rid of the urge and does no real harm.

      2. Great article, am definitely a fat burner. However, I still have a bit of a tummy flab after almost 3 years of being almost carb free. I am concerned about what seems to be a negative stance on ketogenic diets. To stay off insulin, type 1 diabetics need to be in ketosis. How does it cause insulin resistance? Thanks!

        1. Ketosis can be useful in a therapeutic sense for a few different physical dysfunctions. Therapeutic diets aren’t the same as normal diets, so don’t worry about it.
          Ketosis puts the body in a situation where it gets lazy about sugar regulation, not having to deal with it. Bodies are like that, like therapeutic doses of cortisone cause the body to stop bothering to produce it itself. You know?

        2. Are there type 1 diabetics living for a long time off insulin? I never heard of that.

      3. It takes a long time to get over bread because grains are addictive. When the smell of baking bread makes you look for rotting meat then you known you’re there.

      4. In some ways, kicking carb/sugar has been like kicking nicotine! Even cutting myself down to 1-3 cigarettes a day left me still thinking about them and craving them and it wasn’t until I quit completely that I regained true self control over the urges! And in the past when I did “give in” and take a drag off a cigarette, the feeling of satisfaction was completely gone. It’s been over four years free of nicotine now with nary a craving and almost two months into primal lifestyle with fantastic results!

    2. I think with the fresh-baked bread, there’s a strong psychological draw. For a lot of people, there’s a definite comfort factor there. Fresh-baked bread, mom, apple pie…. *sigh* Smells are such strong triggers.

      1. This is the one part of paleo that really requires some effort. Those fresh baked pastries and breads always make your mouth water, and it requires some self-control not to walk in to the shop and buy some. I like to just start thinking about anti-nutrients, or a nice big juicy steak as soon as i smell the baked goods

      2. honestly, I don’t really feel that urge when i walk by a bakery or bread in the window. I don’t think i really ever had that much affection toward bread, but what is hard sometimes is the ice cream! loved eating the ice cream when i was a chubby kid!

        1. I agree. Ice cream is killing me at the moment. I can’t fight this craving in the summer 🙁

        2. Make your own ice cream to ensure it’s more primal! Heavy whipping cream, vanilla extract, just a touch of honey. I made it this way and it’s sooo good, and without all the processed sugar/crap they put in commercial ice creams.

        3. I used to love ice cream too. Have you tried coconut milk ice cream? It’s dairy free, gluten free, and soy free. Pretty yummy if you’re looking for that ice cream taste in the summer!

        4. Yes, Gelato is your best choice!! As an Italian I can tell you that well done Gelato, does contain almost no sugar, a lot of cream and milk. If you use dairy it is a “good compromise”. On the contrary, here in Japan I ate an american ice cream (Baskin Robbins) and it was awful! You should try the real thing, bro…

    3. I so agree!! The smell! The memories!!
      But I also have to agree with Tiffany, it’s just not the same.
      I have come to the conclusion that’s it’s not the bread I am craving so much as the butter ON the bread. I miss the bread as the vehicle for my butter!!
      So if someone could suggest another way to have the butter, I would be a happy girl!

      1. Oh… also cheese. I miss mac’n’cheese and grilled cheese sandwiches, so badly. I can do a fair job of mac’n’cheese with veggies, but I still haven’t found a good outside for a paleo grilled cheese.

        1. Just visited my daughter in Wisconsin and they have this awesome product called “bread cheese.” It’s like the best grilled cheese without the bread. It has an outside crust; you toast it up in a skillet and it gets that terrific cheese crust on the outside and warm and ooey-gooey on the inside. It even comes in bacon flavor. I’m sure someone up there would ship it!

          1. Try The Wisconsin Cheeseman website

        2. Connie just reminded me. I have seen on television that if you put parchment paper where the bread would go and then cook your cheese in a panini press or between two hot cast iron skillets, it will grill the cheese. I have no idea what the outcome is like or the tricks of the trade, but people were buying them so there must be some type of benefit.

        3. Somewhere, here?, someone had the idea to use one of those giant red bell peppers cut in half and flattened to make the “bread” part of a sandwich. Should work for a grilled cheese if you like red peppers.

        4. Just buy a greek cheese called Haloumi cheese, it can be grilled or pan fried… delicious and no bread..

      2. GoRaw Chocolate Super Cookies make a nice holder for a slab of pasture butter, you just have to limit them because of the sugar from the dates and the PUFAs. I eat twelve or fifteen a day at different times of the day. Butter on your soup after it’s warmed up. Even butter in your coffee or hot tea. I’ve been mostly grain free (except for about a cup or two of rice a month) for eleven months, and I don’t miss the bread, oddly, because I used to LOVE it. I think the stuff is so toxic, even the smell might be bad for you.

      3. Not interested in just eating a piece of butter? I like it when it is still waxy so I can taste the fat without it being greasy.
        I also like to mash in xylitol and cinnamon or cocoa powder and go to town.
        Is that wrong?

      4. That factor is why I quit bothering with cheat days. I would get excited about eating a piece of something toxic and then the day would come and I would poison myself liberally and wonder why on earth I was inviting metabolic dysfunction for that really marginal “food” I was eating.

      5. That turned out to be my issue. I grew up on homemade bread and butter made from our fresh cow’s cream. Now I just have some straight up cultured pastured butter and that does the trick. The butter tastes so great that a Tbsp does the trick. Not often, just once in a while.

      6. If it’s really good butter, like Kerrygold, I don’t need a vehicle of any kind–just put a pat of that buttery goodness in your mouth and welcome to zen!

      7. Bake some Paleo friendly bread…..made with almond and coconut flour….its a good substite

      8. Have you ever had buttered radishes? A very English snack – just salt the radish slices, let them sit for a few minutes, then butter away.

        Or, I like to peel a couple of boiled eggs while they are still warm and put them in a tupperware container with butter, salt, and pepper. Shake them around a bit until the butter melts and you have a nice sauce for your eggs. Boil the eggs for a little less than 6 minutes and the yolks will still be a little runny. 🙂

      9. Just eat some Kerrygold butter straight. I know that sounds crazy, but when I get hungry and don’t want to eat a whole meal, I just eat a pat of Kerrygold (by itself) and I’m good. And it tastes SOOO good (even by itself). 😉

    4. I don’t know much about it yet but there is such a thing as having a yeast addiction. Bread contains yeast. So, it could be the yeast in the bread that you are craving. Also, yeast thrives on sugar, so carbs would satisfy those cravings.
      I am wanting to test myself to see if I have a yeast or candida addiction/allergy.

    5. Adrian-You may be closer than you think when you say “addiction”. If you haven’t already done so, check out “Wheat Belly” by Dr. William Davis. Some of the wheat proteins bind to the same opioid receptors in your brain,( meant to be filled by endorphins,) that morphine and heroin bind to.
      Scary, huh?

    6. the fructose in those raisins may be helping keep your addiction going.

    7. Adrian, I have a similar experience. (I’m about 4 months into paleo) I gave up 80% of things I’d eaten before without problem from the get go. Then for a few months I was very strict, and now I allow myself to give into some cravings, which are usually a slice of pizza or bread. As someone said above, if I give into some things – i.e. some fast food or cafeteria “burgers”, a small slice of cake, I find the taste just isn’t as fulfilling as I remember so it’s easy to say no almost all of the time and that helps keep me away. Bread and pizza, however, are just as tasty as before! But what I do find now is my indulgence is one slice of pizza every couple of weeks – this is way down from 4 slices once a week on pizza night! So I consider that a success and allow myself to enjoy what I do have when I have it. I used to love pancakes too and just discovered banana pancakes last weekend which are paleo and taste like a dessert to me, so as I find more substitutes that helps too!


      1. i never give in to cravings anymore. when i see a slice of pizza, what i see is adulterated omega 6 fats building themselves into my cell membranes and paving the way to cancer and heart disease. and I see HFCS ruining my liver. junk is junk and i won’t put it in my mouth ever, no matter the taste. anyone can learn to visualise the negative effects of junk food on his body. very helpful to help resist eating crap.

      2. Liz
        Have you tried making paleo pizza?
        the base is 2 cups almond flour
        2 eggs
        2 cups grated cheese
        bake in oven on baking parchment for 10 mins @180 C then turn over and top as normal then cook until topping is done.

        1. I made paleo pizza by pressing seasoned ground beef into a pan and letting it brown for a few minutes, drain of some of the liquid, then topping it with homemade tomato sauce (no sugar), fresh mozarella and a little good quality pepperoni. Throw that under broiler until the cheese bubbles. It’s a little messy (have to use a knife and fork), but it’s like having pizza and Bolognese sauce all in one meal without the wheat from pizza dough or pasta. Sprinkle with some minced fresh basil.

    8. Thankfully I don’t get that kind of craving for bread anymore. Have you tried maybe a baked sweet potato to try and squelch it?

    9. I know it’s hard to turn your senses off, but I think it helps to view things as food/non-food. I’ve been paleo/primal for about a year and a half and I now look at bread as a non-food item that smells nice, like a fragrant soap or something like that. Soap smells good, too, but you wouldn’t eat that, would you? 😉

      1. Génial! This is so helpful! Thanks for the amazing tip!

    10. Google GRAIN OPIOIDS and MILK OPIOIDS. That should clarify for everyone why they still crave these things. The addiction will probably never go away completely.

    11. Dear Adrian,
      it might be a good idea to check your Alkaline levels(blood acidity)..there may be some other foods in your diet that are high acid base and creating the craving.. check out https://biomedx.com/microscopes/rrintro/rrintro.html

      good luck, discipline is important and it appears that you have that under control at the moment. you’ll be amazed at how our blood acidity affects our overall health…the science is over 200 years old…interesting read.

    12. Adrian,
      That sounds like a very likely case of candida or yeast-related syndrome of some sort. Paleo certainly helps to avoid the triggering foods, but you may need to do a supplement protocol for a while, and be certain to avoid all yeasts and sweet things too. Many resources out there abound on protocols. It’s probably not just psychological or aroma therapy issues! 😉 The smell of yeast is insanely provocative if you have overactive yeasts in your system.

    13. You are simply and ex carb addict. Just like an ex drug addict or ex alcoholic. The urge will always be there but you just take it one day at the time.

    14. Sounds like you could potentially benefit from going zero carb, at least for a time.

      Worked for me.

  4. I am fat adapted and never wanna look back to those sugar-burning day!!!

    Thank you Mark for the inspiration. I love all your posts, so informative and logical. 🙂

  5. Once you are fat-adapted, how long does it take to become un-fat-adapted? If you go on vacation for a week and have a carbfest, do you have to start from square one?

    1. Good question – I’d like to know that too! My guess is that it wouldn’t be “square one” since you’ve already laid down the ground work…but it might take a couple weeks….? Just guessing…no scientific data to back me up. 🙂

      1. I thought that I read a previous post my Mark that said it would take a couple weeks to undo all of the ground work of being fat adapted.

        1. I have been on carb-fests definitely! But usually it is like a meal or two not the whole week.

          But there are times that I started eating carbs, from stress. I would start eating more rice, crave dessert. It was on going for a while. But once I start to cut most carbs out, it takes about a week and I don’t miss carbs again!

          Another thing for me, i found it hard to be on ‘carbfest’ once you are fat-adapted. Because whenever i eat too much sugar, only take about a half a cup cake or 1 piece of cookies, i will start feeling pretty shitty– really dramatic sugar rush and sugar crash, and sometimes i fall asleep 20 mins after i ate carbs.

          sometimes i get sleepy after 1 apple (which contains up to 50 gram of sugar!)

      2. According to phinney and volek’s new book (art and science of LC performance, you can experience a set back in fat oxidation of a couple of weeks. It certainly isn’t just a few hours. This certainly argues one away from “holidays.”

    2. Take a look at what Martin Berkhan has to say about big indulgences, such as a week off or eating pounds of cheescake. I think for me, jumping into a couple of days of long IFing can help to quickly reverse the bad stuff. I do this when it’s a weekend like Thanksgiving. You feel a bit off for that first day after the weekend but then after consuming very low carb and fasting you quickly get back to good status within a few days.

    3. I’m gonna say if you have enough self control to be primal in the first place and can usually go out and eat well despite conventional wisdom pressures all around you, then you should probably do just fine. I had a few friends go to Italy for a week and of course they are going to indulge in the pasta and other italian staples (because you HAVE to in that situation), but they came back and got right back on the healthy train no problem

    4. I’m confused…if you are a sugar burning type, does that mean you won’t lose the weight until you become a fat adapted type?

      1. Shelly, so long as your insulin level is above a certain threshold your body will not burn fat. You will have to eat low-carb and empty your glucose reservoirs before your body will start burning fat. Once you are fat-adapted, this will be the preferred mode of energy conversion

    5. I eat primal / paleo 80% of the time but when I go to the south of France I eat croissant, baguette with cheese and jam, an egg and coffee for breakfast every morning. Then fish and salad for lunches, then a salad or plain Greek yogurt for dinner. I kind of freak about my breakfast carbs those two weeks but when I get home I usually weigh about 5-10 pounds less than when I got there… If I ate like this at home I’d blow up like a balloon. It’s weird.

    6. I just did a 4 day trip to my hometown of NYC from my current digs in Miami. Since we can’t get good bread down here I went a little nuts in New York. I had a butter roll (kaiser roll with butter) and coffee upon waking for four days in a row. I had Indian food with basmati rice twice. I had a hamburger with bun once and I had tacos one night. Plus several beers. After 4 days of this I gained 5 pounds. Upon returning home I went back to my primal diet and lost the 5 pounds in 5 days. My body went right back to feeling like I did before vacation. So I’d say it’s safe to cheat a couple times a year.

      1. Jen, I had a similar experience after spending two weeks in Spain. Some kind of bread every morning, came home 3 pounds lighter. I am wondering if European countries use non-GMO wheat and if that has anything to do with it.

        1. GMOs are banned in Europe. It really is easier to gain weight with American foods than European, even if you’re having the same meals as you would in the US.

        2. yes, Bear is right, GMOs are banned in the EU. I live in the Netherlands and bread is everywhere, but they mostly eat multi-grain. My husband said France is the ONLY place where he will eat the white bread. I have to say, my biggest craving on Paleo/ Primal is… toast. (I eat it once or twice a month). I have got to find some kind of way to get around this.. especially during pms. Perhaps sweet potato or something..

    7. I just tried this experiment while vacationing in California, land of burritos, banh mi vietnamese sandwiches, dim sum, pasta, and fabulous sourdough bread, all of which I ate. I found that my appetite was pretty well suppressed between meals and, after one particularly heavy day of eating, I had a stomachache and a clear message from my body saying,”Do NOT feed me today!” I ate a small meal in the evening because someone else cooked it or I would have skipped. (This, incidentally, would not have been normal in my old sugar-burner days. I could eat heavily one day and still want to eat plenty the next day, too.) I didn’t follow my usual exercise regimen but did get in two runs throughout the week. Came home and weighed almost exactly what I weighed when I left. My conclusion: with some intermittent fasting carby eating can be done for a week without anything much worse than a tummyache.

      1. It’s all about quantities IMO. I eat bread everyday with my lunch sandwich at work and make it myself from fermented whole wheat flour poolish. Just a thin slice of it and I feel good. On the other hand, if I eat a lot of it or worst, crackers, chips, cookies, croissants, cake; I then get stomach pain, heatburns and low energy.

  6. Awesome. According to my answers to your questions, I’m fat adapted. I remember having to eat every 2-3 hours. What a difference to not have to bring a food bag everywhere I go. Nowadays I eat a big protein breakfast and bring one tin of sardines with me for lunch and that holds me until I get home around dark. Great article, I’m going to share on FB.

      1. I’m lucky – I haven’t had one complaint, except for the fact that I didn’t bring them a tin. 😉

    1. Starlene, this is definitely the biggest advantage I have since I switched my diet two months ago. I am now at a point where I feel as if I am always choosing to eat rather than having to eat. It really does change my everyday life, I used to run home from work open the fridge and throw food in my face not caring much what was in it. It really was like a “carb addiction”

      1. Anders, I do remember that. I have an hour commute and boy if I got caught in traffic on the way home and hadn’t had my mid-afternoon “snack” I was like a starving dog when I got home. I’d eat ravenously and couldn’t seem to stop myself until I was so stuffed and then I was so uncomfortable and wonder why I’d done it AGAIN. It was awful. This is so much nicer and I just wish I could get people in my life to understand it doesn’t take willpower. I have NO willpower. When I started to eat this way all those crazy cravings dropped away.

    2. What would you normally have for breakfast? I’m trying to get ideas for better protein-high breakfasts that are easy/quick to make or transportable.

      1. I have the same thing for breakfast every morning at about 7 AM. It’s a shake made of 2 raw cage free eggs, two Scoops pure power whey protein made from grass fed cows, 2 scoops of shredded organic coconut, a cup of blueberries (sometimes other berries)and a cup of almond milk, coconut milk, or raw whole mile if I can get it. I also have a small handful of macadamia nuts or almonds. I work out about 12 or 1 and then have lunch (sometimes I skip it). I can tell you that I don’t get hungry AT ALL until after my workout.

        1. ooo – Please, do tell: which protein powder have you found made from grass fed cows?? No artificial sweeteners or anything?

      2. Idamonster, were you asking me what I normally have for breakfast? If yes, I usually just shoot for 50 grams protein, so about 8 ounces of some kind of meat. I dislike reheated meat so it does add some time to my morning routine. I used to be able to get up and leave 30 minutes after my feet hit the floor. Now it’s a solid hour due to cooking *and* eating. I don’t mind eating reheated or cold bacon. Some days I will cook a mess of bacon and take 8-9 slices cold to eat on my drive to work.

      3. When I do have breakfast, I almost always have leftovers from last night’s dinner. Either that or I have one or two eggs, some macadamia nuts and possibly some organic high-quality sausage. But since I’ve gone low-carb I’m actually rarely hungry in the morning, most days I just eat lunch around 12 and dinner around 6.30.

  7. Phinney and Volek discuss in detail keto adaptation and esp. in their latest book its performance implications. They seem to be suggesting that there is a huge gap in how efficiently fat can be oxidized in keto-adapted (i.e. very efficiently) and non-keto adapted individuals.

    Mark, what you are now suggesting is that the gap is not that large, i.e. you don’t have to be fully keto-adapted to be able to use fat effciently.

    Now, how do you know that it is true for all/most people?

    1. I am also interested in hearing a reply to this. Volek is conducting research in this area and is suggesting that optimal fuel flow occurs when one is keto-adapted (a term coined by Phinney). This article borrows his terminology and makes some claims. It would be great to see the science or at least the thinking behind those claims.

  8. Agree with others that fresh bread is an amazing smell, especially for a frenchman. Thankfully I have a saving grace on that front: being wheat intolerant means the pain/ discomfort post eating bread is really not worth it!

    Evil tempter that is bread…

    1. I always loved the smell of gasoline, but I wouldn’t drink it 😀 Some things appear very attractive, but the knowledge that your body either treats it as a toxin or just doesn’t have a need for it usually puts me off enough that I won’t touch it; and just the memory of how bloated and irritated I would feel after a lot of bread puts the nail in the grain coffin for me.

    1. Me too,
      A year into Primal, I have lost 13 kilos, and have no intention of finding them, but I have at leat 10 kilos to go. I rarely eat breakfast, just have a coffee and cream (yum), may have lunch, and then have dinner around 7pm. Not hungry! Seriously, I justdont get hungry, very rarely have that knawing, shakey, crabby hunger I used to get especially in the afternoon.
      I think it’s about healing. I feel my liver still has healing to do as well as my thyroid, which has been sluggish for years. This is the first winter where I haven’t been cold, my skin hasn’t split around my fingers and my heels haven’t looked like wood rasps, so I am hopeful. Getting some blood tests done soon. Fingers crossed. For me at 50 it has been decades of decline before my turnaround, so I can’t expect instant results. But I think I am fat adapted, just quite healed. Hang in there,

      1. Most of us are deficient in vitamin D and magnesium (and other minerals). You can supplement with 10K of vitamin D and 400 to 600 mg of magnesium and that could help a lot. Read The Magnesium Miracle by Dr. Carolyn Dean. You might want to get your estrogen/progesterone levels tested, too, and supplement with wild yam-based products.

      2. Heather, I don’t know what your diet was like before going Primal but if it contained a lot of trans fats then that may be the reason.

        I can’t provide good evidence for it but I have read in other places that trans fats can cause weight gain that is really difficult to get rid of. The best link I can provide at the moment is this Wikipedia article which discusses briefly the body’s ability to burn cis fats but not trans fats.

        Unfortunately I can’t provide an immediate solution for you except to say that getting rid of a lifetimes worth of trans fats is probably going to be an ongoing process (especially as we occasionally fall off the wagon and replenish our McDermis!)

        Would like to hear what other’s opinions are on this.

    2. Do you IF? If you’re trying to lose weight and have an issue with creating a calorie deficit, 1-2 24hr fasts a week will definitely get you in a deficit. And if you truly are fat adapted, then a 24 fast shouldn’t scare you.

    3. Thyroid issue? Maybe you need iodine (try kelp, lobster, something high in iodine) Also, read Mark’s article about ‘stubborn fat’. Usually this is the ‘beer belly’ on men 🙂

  9. You mentioned in your article that Nighttime eaters have higher RQs.

    I have been Paleo/Primal for 14 months now and have lost 90 lbs. I only eat when hungry and that typically means one meal around 7 – 8 PM and then some Paleo Snacks if still hungry and usually bedtime at Midnight to 1 AM. I am not hungry the rest of the day.

    Seems to work for me …

    1. Everyone is different. I’m sure Mark meant to say that nighttime eaters USUALLY have higher RQs because most of those ppl tend to be sugar adapted. You’re probably doing so much right that eating a lot at night has very little negative effect. I eat 2 large (primal) meals a day lunch and dinner. It works for me…and my schedule.

  10. So, I can go hours without a meal no problem. But I still have long periods of brain fogginess, despite being primal for over a year. What am I doing wrong?

    1. I’m a bit like you, Scott – although not primal for quite so long. Due to my work hours I’m pretty sure I’m not getting enough sleep plus, I’ve also got very little to do at work during the day (apart from reading the back blogposts on MDA) and this leaves me tired and, along with the freezing cold, craving carbs/calories.

      1. Have you guys had your hormone levels checked? The tired and cold and foggy part sounds like it might be thyroid and/or adrenal related. I’ve been primal less than two months, lost a ton of weight up front (20 lbs), then stalled. I happen to have a really great doc, who got a bunch of lab tests and it turns out my ACTH and cortisol are both extremely low. So is my thyroid (T3) but I understand from Internet research that trying to adjust T3 in the absence of adequate cortisol is futile. So, cortisol first and thyroid later this summer. Try talking to your docs and see if you can get checked. If your levels are fine, at least that’ll be one thing you can cross off your list! Good luck.

        1. Most people are iodine deficient. Read Dr Donald Miller on iodine supplementation.

          Next, learn how to make your own Lugol’s solution.

        2. Thanks — that’s certainly a possibility. If I get them checked, and they are low, then what do you do?

    2. Scott UK, I don’t do caffeine these days so I no real ‘focus-puller’ for brain fog. Used to be hell on earth for me.
      But zinc, oh my.
      If I’m slow/stupid for a while and red meat/egg yolks aren’t cutting it I squirt some nano-ionic (liquid) zinc in a mug of some fine brew and *bam* -I do me some fine sharp thinkin’.

    3. Not sure what could be causing the brain fogginess. But as for the freezing cold, Martin Berkhan has addressed “cold hands, and feet” during long fasts as blood being diverted from your extremeties to your “fat areas” to be metabolised into energy (or something like that, i hope i didn’t butcher the explanation)

      1. Thanks JPizzey but it’s winter for me so the cold is due to the subzero (celsius) overnight lows and being stuck in a workplace for 13-hours a day that I can’t heat effectively – there’s only so many hours I can spend on the treadmill or elliptical to try and get warm!

    4. Scott, have you tried drinking broth? I had a significant problem with brain fog that just wouldn’t go away. After reading various sources I discovered it was a sodium deficiency. Low carb eating can be a significant diuretic and can wash away a lot of sodium. I also believe I produce insufficient amounts of aldosterone. Fortunately, a couple cups of broth a day fixes me right up.

      Try it. It’s harmless and the effect will be almost immediate if that’s your problem. Plain old bouillon cubes or granules is what I use. Works like a champ.

      1. Bouillon is rampant with monosodium glutamate(MSG), which, in the long run, will have worse effects on your brain. Making your own broth with free range, organic chicken seems a better choice, I would think.

    5. Thanks for all the comments. I think my diet is ok, but will take another look through fitday (including iodine).

      Previously, I noticed that, despite not being hungry, I just wasn’t eating enough calories (<2000). I redoubled efforts to eat even more fat, and have recently added more acceptable carbs back in, but it doesn't seem to help.

      Hormones are a possibility. I have a health check coming up and so will investigate. But what do you do if they are low?

      I do make broth, but tend to keep it for sauces etc. But I will try downing pints of it!

      I'm off to Google nano-ionic (liquid) zinc now!

  11. Yay! I’m a fat-burning beast!

    Primal for almost ten weeks, I’ve lost 22 pounds and I can easily go up to eighteen hours without eating (as long as half of those hours are spent sleeping).

    This post is exactly what I wanted to know. Thanks, Mark!

  12. Responding to your question I think I’m fat burner, I can do fast without being hungry, but then because I gained weight with paleo?

    1. I’ve actually gained a significant amount of fat since going paleo/primal. It’s very frustrating! I feel healthier, and my mental health has vastly improved, but there’s no doubt about it, I’ve put on more than 10lb of fat (from 135lb to 149lb). I wanted to lose weight, not gain it!
      The mental health benefits (my depression is almost completely gone, it seems!) make it worth staying primal for me, but I sure want to be losing weight and not gaining it…

      1. Are you SURE you gained fat? Are your clothes actually tighter? If not, you may be gaining muscle which is very worth it, even if you gain overall. 😉

      2. Do you get regular low-cardio exercise? Do you sprint every once in a while? While diet is a big part of weight-loss, a low-carb diet can and will lower your metabolism unless you tell your body to keep burning fat by exercising frequently.

      3. I had the same thing happen!!! I used to be 5′ 8″ 123 lbs, and now I am 130- 132. My clothes are tighter!!! I am a bit more muscular, but my belly seems to be thicker as well. My husband tells me it is because I am actually absorbing my food and nutrients now, where as before I couldn’t gain weight if I tried (I was definitely carb addicted). Thing is, I was happy with my weight, I went primal for health – which I can say is much improved 🙂

      4. I know exactly how you feel, and what I did was NOT DO any high intensity workouts…or Crossfit. I walked more often, lifted heavy, and sprinted. That fixed it. Oh and I eat fruit only once in a while. Mark has addressed numerous times that fruits are something you should limit if you are trying to get rid of fat.

  13. Having PCOS, I don’t think Ill ever be “fat-adapted” and I don’t think that will ever change for me no matter how well I eat. Is that a bad thing?

    1. I have pcos as well and if you sick to it, you can become a fat burning machine. It’s a little slower going but it’s a world of difference when it happens. Like day and night.

      1. Another PCOS gal who primal’ed herself out of the diagnosis, per my very happy endocrinologist. I’m a fatburner (now) and I’ve still got a LOT of weight to lose. It’s entirely possible.

    2. You have to consider that there are 3 categories of women with PCOS: 1-women who have PCOS due to being overweight, 2- due to insulin not being regulated, 3- other. If you fall into the first or second category, then you can leave PCOS behind through being disciplined. However, if you are one of the 1% of women who fall into the third category like me, you will most likely always have PCOS. My endocrinologist says that it has biological factors- extremely oversized ovaries which are not organs that you cannot shrink with this or any lifestyle. With that being said, having PCOS in no way prohibits you from being fat-adapted. This is something you still should be able to accomplish and be healthier for it in terms of PCOS (even if it doesn’t eliminate it).

    3. I also have PCOS (I prefer to call it insulin resistance, that’s the root cause, excess carbohydrate comsuption). I came from your ordinary “healthy” vegan diet (which I was constant hungry, having to eat every 2 hours, it was hell, I was always anxious counting the hour for my next meal, used to eat 8 fruits, 2 bowls of oatmeal per day, etc). I was exercing a lot too, but it was only getting worse because I was gaining weight on my waist. But converting to a paleo lifestyle, and now keto, I got the low carb flu, it lasted 1 week I think, but 2 weeks has passed and I’m better than never before, gained lot more muscles on my legs (which is great because since us with insulin resistance store fat on arms, breast and belly), I’m doing heavier strenght training without getting tired, I was able to walk on the treadmill for 72 min without getting tired. Now I’m eating mostly fat and low carb veggies.
      I wish so much to reset my insulin resistance and finally be able to put weigt where it should be in a female (hips, thighs and butt), I’m still 17).

  14. Fat adapted does not necessarily mean ketosis, but how about the other way around? If you’re in ketosis, does that mean you’re fat-adapted too?

    1. No. Ketosis is merely the state of producing and burning ketones rather than glucose for some biologic functions. If you stay in ketosis long enough, your body will fat adapt. Initial adaptation, which involve digestive enzimes and such adjusting themselves to the higher levels of fat usually takes a few days to two weeks. Full adaptation can take several weeks or months.

  15. Fascinating read – thanks Mark.

    I would be interested to know your position regarding pro endurance athletes (e.g. triathletes) who fuel themselves with gooey energy gels to get through their heavy training sessions. Perhaps some of it is just brand marketing but these guys are super lean (probably due to the vast amount of calories they burn) but surely they are sugar burners!? Or perhaps because they can never put enough calories into their bodies to make up for spent calories, they are fat adapted…

    Personally, I can get through fasts and am well aware of the feeling of my body taping into fat stores for energy – I would like to do it more but I do still rely on quick energy (e.g. gels) if I’m out on a tough ride.

    1. These pro athletes are definitely carb / glycose burners. However I would argue that the sport choose them and not the other way around. They are not lean because they run, they run because they are lean.

      They take the energy gels during runs because they need to replace their glycogen stores. I have just finished reading ‘The Art and Science of Low Carbohydrate Performance’ by RD, Jeff S. Volek PhD and PhD, Stephen D. Phinney MD.

      Interesting book if you want to know more about endurance exercising on a keto / low carb diet

  16. So, you described the differences between the two, but how do you become fat-adapted?

    1. Exactly, please tell me how to get from a sugar burner to a fat burner!

      1. yes, I want to know. I’ve been primal since April and I’m not fat adapted yet. Doing Whole 30 now for almost 2 weeks, still not fat adapted.

  17. I realized yesterday that I was fairly fat adapted. Breakfast consisted of two eggs (free range from a friend’s chickens) and a half cup cottage cheese, forced myself to eat my lunch around 1pm which was a large salad and a side of coleslaw; went to a movie with friends after work and friends said at 6pm when the movie let out “I’m starving!!!” And all I said was “well I could eat.” It was really impressing actually and I’m glad you wrote this article. I llloooovvveee that you added to RQ, I’ve never heard about that and when I read it, the science need in my went crazy!!!

  18. I don’t guess I think about food that much. To me, food is something I intake to get the nutrients I need to survive and maintain good health.
    I never ate much sugar (a little in my coffee, but not for months now), and when I quit bread etc. I just didn’t think about it that much afterwards. Maybe I just didn’t eat it that much to begin with? who knows…..

    1. I am with you Sandy, food has always been like fuel in the car. Can’t go without it. Never been a social (or emotional) eater, and probably been fairly fat adapted my whole life. Always did better on eggs for breakfast, if I ate cereal I’d feel like there was an alien I ther trying to claw out. Nasty feeling! Never ate much shit food either, too many kids not enough money! Lots of veggies and chicken, meat, never was given snacks, just a piece a fruit or bread was all there was…lucky me! Honest!. I was gardening the other day, skipped lunch was too busy building the retaining wall. I do my weights 3 times a week at 6am and don’t eat till I get home. And not completely primal yet but probs always fairly fat adapted.

  19. Here’s my problem…..I come from big people. Not an excuse. Just stating a fact. It doesn’t seem to matter how many meals I skip or if I cut everything with any kind of sugar and carb out. I stay the same. I lift weights in a semi-amateur body building sort of way. What is wrong with me? I am starting to lose hope that I will make it to old age and see my kids grow up and have kids of their own (obesity being the number one underlying cause of death and having diabetes on both sides of my family). I would really love to see that scale register even at the high end of acceptable weight for my height. And yes, I have had my thyroid tested. Sadly, I am fine.

    1. I have been there and at times given up. Hitting a plateau is not fun. Best thing is to be strategic and figure out what works for you in terms to nutrition and exercise. There are tons of free resources available. Don’t give up! You can do it. I found out what worked for me and documented it on my blog.
      Cheers 🙂

    2. but, are you borderline? sometimes that is enough to throw you out of whack. also, have you had your hormones tested? sometimes those can be “within range” but still one can be a little off from the others and that can throw you off. that being said. sometimes you can’t cheat genetics.

    3. Have you tried Crossfit? If not look into it. May help different workout each day to mix it up. May hit your body differently

    4. I am in the same boat you are in. On my mothers’ side everyone is fat. I mean everyone. We all live very different lives and in varying places but we all have the same body shape. I am always about 50 pounds overweight.
      I have a photo of my great-great-grandmother during the depression. She was basically a dirt farmer, and had very little to eat. But there she was standing next to my thin as a rail starving great-great grandfather plumb as can be! I really do believe that some people are genetically fat. We all eat very differently and live all types of lifestyles, but we all end up looking the same.
      I focus on being healthy. Eating right and exercising some. On a bright note, even obese everyone who is fat in my family lives well into their late 80s. Who knows?

    5. When I first had my thyroid tested, my GP said it was “normal” and therefore there was nothing she could do. Nevermind that I had weight I couldn’t shed, very low energy, and brain fog, among quite a few other telltale thyroid symptoms. Nevermind my prior diagnosis of Hashimoto’s and family history of the same. As long as the lab said “normal” she could/would do nothing.

      I found out I was at the high end of the normal range for TSH, so I started reading up on it and discovered how controversial the normal range actually is. When they established it, they included people withy hypo symptoms in the normal range. That was the beginning of a very long journey for me.

      I found another doc who would treat me, and about that same time I discovered PB. I’d read all the stories of people who found the weight just falling off them when they made the switch, but that’s not how it happened for me. I lost maybe 5 lbs (of the 40+ I wanted to lose) initially, then nothing happened.

      I eventually sought treatment for both adrenal fatigue (the thyroid treatment had helped some, but not enough) and candida. I don’t know if it just took me longer to see the benefits of PB in terms of weight loss, or if the key for me was really dealing with those other two issues, but immediately following the candida treatment, I began losing weight steadily. Not rapidly, but steadily.

      I have a little more to go, but I can’t tell you how satisfying it was to see my BMI drop down from the obese range into “just” overweight. I’m only a couple of lbs from the top of the healthy weight range for my height now, and it’s an awesome feeling to have it within reach.

      Without knowing what (if any) symptoms you’re struggling with besides the stubborn weight, there’s no guarantee my story means anything for you. If it’s important to you to move that particular needle, I’d encourage you to not give up and (if you haven’t already) to consider finding a doctor who wants to treat your symptoms, not just your lab results. They aren’t everywhere, but they do exist!

      I wish it were as simple in our medical system today as to get one thyroid test and know for sure you really don’t need treatment. Unfortunately, it’s just not. It’s also complicated by the reality that there may be more than one problem to solve.

      One of the most encouraging things I can say is, it’s at least a huge advantage that you’re here. I knew I needed to lose weight, but my focus all along was on regaining my health. I’ve always believed that if my body is truly healthy (and being fueled in a healthy way), the weight will resolve itself. It may take longer, but I still believe PB is a huge part of the progress I’ve made. I wish you all the best!

      1. Karen, thank you for your story. I am currently waiting for my blood work results to see if I have a thyroid problem. My family has been on BP now for several months. My husband has lost 45 lbs. and is feeling great!
        I initially lost about 6lbs and that’s it. I was already pretty low-carb though so the change wasn’t as drastic for me, I guess.
        Since being wheat and grain-free I’ve had less trouble with headaches.
        My new doctor suggested topical progesterone cream for the headaches and fatigue during periods etc. then, I decided to quit dairy completely and try to reintroduce it back in slowly to see if I’m intolerant or allergic. By the 3rd day I was miserable and thought maybe it was side-effects from the progesterone so I quit using that! The next day I looked up “dairy withdrawals” and discovered that that was what I was dealing with: terrible headaches, brain fog, nausea and acidity etc.
        I am just at the beginning of my journey trying to figure out what’s wrong with me. I have very low energy, get headaches a lot and since starting eating primal I have a lot of stomach acidity and just general unrest. I did have treatment for H-Pilori several years ago.
        I will be 40 in a few months. I have 5 kids and my Dr. Thinks I probably have an unhealthy gut due to childhood illnesses and living in 3rd world countries when I was young and just the physical stress of the pregnancies.
        She did give me a book to read on adrenal fatigue. I am also very interested to know more about candida and how it manifests etc.
        I am not hugely overweight but would like to shed 30 lbs or so.
        I was very interested in your story because you went on a journey to figure out your body and what was out of wack and I need every bit of help I can get!
        Thanks for your post

        1. Boy, it sure is a journey for some of us! I resisted thinking about it that way for a while, and all that did was depress me further – clearly no results in resistance! I truly believe that if we treat our bodies well, they have amazing power to heal themselves and overcome prior damage done. Sounds like you’re off to a good start and headed down a great path. I just turned 40 a couple of months ago, and I can’t tell you how much better 40 feels physically than 39! Best of luck to you!

      2. Karen, would you mind sharing what you did as a candida and adrenal treatment? I think I have both problems, and my symptoms are similar to yours. There are so many treatment options out there for candida in particular, I am lost. Thanks!

        1. By that time I was seeing a naturopath, who was initially only treating my thyroid. I was still really struggling with fatigue and some other symptoms, and the weight wasn’t coming off (in spite of roughly 90/10 primal eating). I asked her about possible adrenal issues and she had me do a saliva test (take saliva samples 4 times over a 24 hour period and mail into the lab).

          I don’t remember the details of the results, but they confirmed that my cortisol levels were low at times of day when they should have been high, and high when they should have been low. She prescribed several supplements that I took for a few months. Of course she also encouraged me to work on stress management techniques as well, like yoga, regular and adequate sleep, taking more walks (but not necessarily working out with intensity), etc. My results also showed I was low in DHEA, so she supplemented me there, as well.

          I believe that treatment was all necessary and helpful, but I still didn’t feel my energy levels coming back to where they should be. I read that candida symptoms overlap a bunch with both the adrenal fatigue and hypothyroid symptoms that I was still struggling with, so I asked her about it. I’d had nearly all of the lifestyle factors that are considered causes of candida overgrowth: crappy diet as a kid and young adult (HUGE sweet tooth), lots of antibiotics though my life, and use of the birth control pill. She prescribed a one month course of nystatin and advised me to follow her version of the candida diet (there are several variations) for six weeks. Given that I was already 90/10 primal at that point, the only real change was cutting out wine and dark chocolate completely (they were occasional indulgences), and further reducing my fruit intake.

          It seems to have done the trick! My best recommendation to you would be to find a good doctor who’s first and foremost even aware of (r believes in) both adrenal fatigue and candida, and understands how our bodies can heal themselves with some nudging and guidance (as opposed to pharmaceuticals). In my observation, that’s generally going to point you away from a GP or endocrinologist and toward a naturopath (though I’m sure there are exceptions). In my case, that’s meant spending more on my care, since my naturopath is out of network for my insurance. But, I couldn’t argue with the value of the results.

          Hang in there and keep the faith that you can and will feel better! I wish you all the best!

      3. Hi Karen,

        Thank you so much for sharing. It’s almost refreshing to learn that there are others for whom the weight didn’t just melt off. I’m very impressed that you stuck with it, and more motivated to learn that the weight did eventually come off.

        I love your attitude of focusing primarily on health! can you shift my paradigm for me? 🙂

        1. Thanks! I remember feeling very discouraged initially that my results weren’t as instant or dramatic as the wonderful, inspiring success stories I was reading. I believe that primal is the right dietary (and lifestyle) path for me, and ultimately realized that I had more work to do with my body before it was prepared to let the weight go.

          I don’t know if this will help shift your paradigm or not, but there are a few things that helped me get to a focus on health rather than just weight loss. 1) Knowing several “skinny fat” people, who may be able to wear a size I envied, but were still at least as unhealthy as me – skinny doesn’t guarantee quality of life or longevity at all. 2) Reading at one point that adrenal fatigue (and hormone imbalance in general) can be brought on my something I’d never heard of before… dietary stress. The author meant that if we’re putting things in our mouths that our bodies can’t tolerate or process well, we’re inflicting a different kind of stress on it. It occurred to me that this may be the form of stress I have the most direct control over, and that I wanted my body to have the best possible fuel so that it could help me survive through the other kinds of stress I can’t always control. That is what led me to find MDA. 3) Reading on MDA how much impact diet has on body composition, and how by us focusing on eating well enables our bodies to do the rest of the work to be truly well… which inherently means fitter and (often/usually) thinner.

          Hang in there, and stick around this place. I’ve discovered there’s plenty of variety in this community – we’re not all quick losers, but we’re all getting healthier!

        2. Try the Navitas (or other brand) organic raw cocoa, there is no sugar in it, you can use it in shakes or yogurt for example.

      4. Surprising that cutting chocolate and wine helped you, it must be specific to your condition.

        Cocoa is generally very healthy, especially little processed organic raw cocoa and red wine (although not to abuse) and better organic red wine is good to prevent coronary diseases, google “The French paradox” for more info.

        1. You’re right, Geo. Most versions of the candida diet have you abstain from all alcohol because the yeast will feed on the sugar. The idea behind the diet is to encourage die off by starving the yeast. Wine was really the only alcohol I was having by that point, and only in small quantities.

          I probably could have continued with the chocolate, since I was only eating small amounts of 72% dark, but I usually enjoyed it with my wine. No more wine meant I thought of it less often. Also, though this was probably silly, I was scared to push my luck with any sugar intake. Though it’s a vast improvement on my old Snickers habit, I still think of chocolate as a candy.

          I agree with you about the benefits, though, and I enjoy them both again now that I’m done with that treatment. Cheers!

  20.  I never ever eat sugar, but occasionally if out to dinner at an upscale restaurant I’ll have artisan bread because I love it, and sometimes I’ll have potatoes, but this isn’t often, less than once a week, sometimes less than once a month. 
    I got really fat from four and a half years of psychmeds, along with a plethora of other adverse reactions and side affects. I’ve been off all medication since late November 2005, although the withdrawal lasted a very very long time. 
     I feel better, way better in fact, since I went low-carb over a year and half ago, and I’ve lost nearly all the weight. I’m fairly certain the medication caused me to be diabetic, I have a blood glucose monitor but I only use it when I know I’ve been undisciplined with my diet. 
     But I still faint sometimes (last time spent in ER for fainting while waiting at bus stop was a year ago, but the heatwave right now is kicking my butt), often I feel extremely weak, and brain fog HA I’d forget my head if it weren’t attached. I’m wondering if this is permanent damage from the pharmaceuticals, menopause(last period more than year ago can’t remember exactly), the diabetes ll, or maybe something else. In late 2005 early 2006 I had a battery of tests at the county health dept. I guess everything was okay even though I nearly keeled over on the treadmill. 
     Anyway, I ride my bicycle everywhere I go, walk more than anyone else I know, can sprint for the train or bus, but sometimes I just feel like somebody let all the air out of me, why is that?

    1. Hummm….do you eat enough fat? Try an experiment and see what you sugars do at 1,2,3 etc hours after eating. Then look at what you’re actually eating and tweak it a bit. Are sugars stable? If you have been diagnosed diabetic, then know EXACTLY what your blood sugar does with food, it might help you to reduce feinting IF thats from low blood sugar. Might not be, so when you know sugars are stable but youre still feinting, then the doctor is a good plan. I am brain fogged but I know mine is all hormone related (dropping progesterone levels) and it fluctuates. I am still experimenting to see how food, and WHAT food helps. Psyche meds retain fluid too, that can be a lot of the weight loss too. Good luck. Keep digging until you know you body intimately – there is where many answers can be found!

    2. Have you considered that you may have a candida overgrowth? Most likely after the medication you were on. Google “candidiasis” or “candida overgrowth” and add a yeast killer to your daily regimen, as you are already doing the diet for candida (low-carb is essential as candida lives on sugar). You also need to get kefir, much better than a probiotic pill, it’s live and much better for you than the pills. That and real sauerkraut. My husband and I have been fighting candida for 5 years now, off and on. It causes sugar or carb cravings as well, so that could be the cause of many people’s carb cravings. Do yourself a favour, you can’t be better without rebalancing your internal flora.

      1. River Song, I DID just Google it: “To treat what they refer to as Candida, some alternative medicine practitioners have recommended avoiding antibiotics, birth control pills, and foods that are high in sugar or yeast, ostensibly to “eliminate excess yeast” in the body. However, there is little clinically valid evidence that these “Candida cleanse” treatments treat intestinal candidiasis effectively, or cure any of the symptoms claimed by the proponents of the hypothesis.”

    3. There are a number of things that could be causing these sorts of symptoms, but give your history of psych meds and a suspicion(?) of diabetes, I suggest you read “Sugar Nation” (Jeff O’Connell) – it’s the story of a sportswriter’s experience of reactive hypoglycemia, and his journey to and eventually precise diagnosis. If you see yourself, which I suspect you will, then you definitely do need to see some docs ASAP.

      His story will give you some valuable guideposts to diagnosis and treatment – even if you have to dig up the same docs or clinics.

      Don’t delay – if this is the case, it can be quite dangerous if unmanaged. And, not unusually, it’s often unrecognized and untreated.

      In any case, I would encourage you to tap into your inner pitbull and keep searching until you get satisfactory answers. Periodic fainting is a big red flag.

      Good luck.

    4. psychmeds are poisons known to wreak havoc on your body and it could take a long time for your liver, kidneys amd pancreas to recover from the devastating effects of the drugs, just thank the FDA for it. A friend who had an accidental depression ballooned quickly while on meds but she mostly recovered.

      For a different reason my wife had fainting events, I recommend that you eat less but more often, that will prevent your body from playing yoyo with your blood sugar level and do not eat sugar and starch at all either. I know it’s hard, I do love bread and make it myself, eat it as well in small quantities but I’m in good health. If you use a testing kit you can also verify what quantity of bread will be acceptable or not but even small amounts of sweet cake will make your blood sugar level explode.

  21. Hi I’ve been hitting primal for around 8 months now, I’m currently doing a lot of Crossfit I don’t feel I need to eat every 3 hours but I’m trying to put weight on. I’m staying away from carbs,cut hitting the meat hard. Is it such a bad thing to be eating every three hours? As long as I’m having primal meals is this still ok? It didn’t mean anything to me leaving bread behind feel so much better!! Be interested for some feedback thanks in advance

    1. Cut back on the Crossfit, and lift heavy with good form for less reps. Works like a charm.

  22. I think I am and I must admit I don’t feel hungry every few hours like I used to (actually I trained myself to eat every 2-3 hours coz that’s what I thought I was meant to do!). Sometimes I not even hungry really around “dinner time” but I eat coz it’s that time and it’s nice to eat with my partner. I am doing my first I.F this morning (skipping breakfast), and although I could eat it, if I really thought about it I am not that hungry, it’s more out of habit. If I eat when not hungry its usually coz im bored but not I am making an effort to move more I don’t have as much time to get bored. Another great think about eating this way is you save money – you spend more on good food but your eating less of it. Phew that was a long post! But I just get so excited about it all.

    1. Oh dear just read my post, sorry about the terrible grammar. It’s early here in nz.

  23. After going primal how long does it take to become fat adapted?

    I am still working on making my own mayo and salad dressings and still eat some grain fed beef. It’s been about 2 months though of no grains and no sugar. I am not yet fat-adapted and have not lost much weight yet.

    1. i have the same question, Susan. I never seem to go into fat burning mode–paleo, primal and atkins (followed all of them for a least a month each, paleo and atkins for two months each, with strict adherence) and initially lost a pound or three and then gained that back plus more weight each time. i am starting to question whether there are some people who are slower to convert or possibly unable to convert despite what our bodies are “normally” able to do. i am a lifelong low fat, high carb eater and i wonder if i’ve just trained myself into permanent sugar burning (or at least to the degree that two months wasn’t able to reverse it). i can’t stay on longer than 2 months yet because i’m unwilling to keep gaining in order to find the “wall”…it’s too demoralizing.

    2. I was wondering this exact thing. I’ve been an athlete since middle school and I’ve had low-blood sugar problems for almost as long.

      Recently, I decided to take the dive and really try to go primal. The prospect of not eating every 2-3 hours is amazing to me! Unfortunately, I’ve been programmed to eat that way for so long that even though I’m no longer feeling faint and shake-y after a few hours, I still feel very hungry and tempted by eating anything and everything.

      I can feel that my body is already making adjustments, but I feel like I’m no where really near the level of fat-adapted that I would like to be.

  24. I ate dinner last night, woke up this morning, drank some coffee, went to the trailhead, and hiked Mt. Audubon. 8 miles round trip, 2750 ft of elevation gain, 3 hrs 20 min car to car. Drank a little water on the trail, and got home, walked to the grocery store, and got some salmon and greens for lunch. It is so nice to be fat-adepted—constant energy level, no need to snack.

  25. I just stumbled on to this article, so I’m looking for a little synopsis here: What is “going primal” in its most basic sense and what is a good resource to start with to bet some more info on this topic. The comments really peaked my interest!

    1. Glenn, go to the ‘Start Here’ tab at the top of this post then scroll down to ‘The Basics/Primal Blueprint 101’ – all the information you need to begin following The Primal Blueprint is available on the site.

  26. I’m getting there. I did lose 30 pounds since January without trying.

    I used to get really cranky an hour before meal time. That’s gone away. Missing a meal doesn’t feel like a big deal.

    Probably still eat a bit more carbs than I should for weight loss, but not stressing too much about it has been good for me -and the pounds have slowly come off anyway. I think now that the farmers’ markets are in full swing it should be easier to buy good food, so that will help.

    There’s even a guy who sells grass fed beef there.

  27. The smoothing out of my energy level has been the single most important and life-changing benefit of this diet. It has put my sleep cycle back into order and increased my productivity in school. 🙂

  28. Great article, Mark! I have a question, though. I’m pretty sure, based on your article, that I am fat-adapted. Very rarely, I will have a “cheat day”. I pay for it the next day by feeling so lousy, that my cheat days are, maybe, only once every several months now. Hoping to make them even rarer than that! On the days I cheat (with various carbs–dessert-type foods, usually)I notice, almost like clockwork, intense cravings within a few hours after each indulgence. Does this mean I am not officially a fat burner? Or, is it normal for people with naturally low blood sugar levels to be so sensitive to diet changes–even for a day? I have been primal now for the past 3 years. Before going primal, my naturally low blood sugar levels demanded that I eat carbs frequently–as often as every few hours. Otherwise, I would feel very light-headed, shaky, moody, and general lethargy. The side-effects of my low blood sugar issues are completely gone when I eat Primal—and I don’t miss those side-effects, either! Would love to hear yours (and other’s) ideas on this. Thanks!

  29. Am not yet totally fat-adapted, still have occasional severe cravings 5 months into this. However when the engine is running ‘fat-adapted-ly’ … Its a joy… No cravings! No afternoon naps (was calling them my ‘post-donut snooze times’!)!!!! Headaches…gone!! Skin rashes….gone!!! Problems going to b’room….gone!! Food tastes extravagant!! 30lbs ….gone!!! I’m seriously clear headed!!! I need to loose 100 more lbs… If its this easy, I don’t care if it takes me another year!!! Love it love it!!!!!

  30. I had stalled with my weight loss while eating very low carb for a while. It was frustrating, and I figured it was just muscle gain, but at the same time it didn’t seem that i was losing fat.

    Jimmy Moore recently made a post, here (https://www.marksdailyapple.com/what-does-it-mean-to-be-fat-adapted/#more-30142) about his month long experiment testing and optimizing his state of ketosis. He mentions how some people think of low carb as high protein, but how it is actually more about moderate or adequate protein. I never thought (or maybe completely understood)
    how protein can be converted to glucose by the liver, and he claims that about half of all protein you consume is converted to glucose, producing an “anti-ketogenic” effect similar to excess carbs.

    Based on how much protein I was eating, I thought that could be why I had stalled for so long. I decided to cut my protein intake down and eat more vegetables in it’s place. It seems to work for me. I have lost weight again and it is definitely fat loss. About 10 pounds in the last 2-3 weeks, after having been stalled or slightly increased weight for 6+ months. Strength is the same. I can also go even longer without feeling hungry. It is a big relief to have found an answer for my stalled weight loss.

    I imagine many people on here know all of this already, but Jimmy’s post made it “click” for me, and it sure seems to work. Just wanted to put it out there as I have read comments from people who have stalled and even regained some weight on low carb. Too much protein being converted to glucose could be the issue. I was eating a lot of it myself and it seems like that was the case for me. I encourage anyone to read his post on the subject and post your thoughts. Hope it helps!

  31. Just so you know, neurons (those things that make up your brain and nervous system) can’t burn fat, and are only capable of obtaining energy from glucose. Food for thought (no pun intended).

  32. I meant to say I started eating more FAT and vegetables in my comment above. Sorry.

    1. Hi Keith. I did the same; cut the protein after weight loss stalled. It did the trick and I’m losing weight again. Yay!

  33. Hi, I started eating primally in mid March this year – have lost 14lbs which might not seem a lot, but this is the only program that has worked for me so far. Previously a lacto-ovo vegetarian for 17 years – have also started eating fish again as I had extreme cravings for it over the last 2 years. Coincidentally,I became crippled with osteo-arthritis in my hips – had to give up dancing/performing and teaching dance (not being physically capable of dancing – for me – really sucks!). Not sure if it’s all the fish and cod liver oil and/or the weight loss, but this week, I’ve been able to ditch my walking stick and am hopeful that I will soon be able to dance again, restart karate classes,go scuba diving and even take a long walk for fun! Other great things; I can easily go all day without a meal/I feel great – knowing that each week I’m losing a steady 1.5 – 2lbs without starving myself/my food bills have gone down ‘cos I’m not buying or eating rubbish,generally eating less!Hardly touch chocolate – just doesn’t do it for me now! My husband is tentatively trying the program as he is so impressed by how easily I’ve lost weight! Next step is to start the Primal Exercises, etc (within my current limitations). Thanks Mark, for your great website!(Thanks also to my sister, who gave me the website details – she too is losing weight which she couldn’t before!)

  34. I’m in my fifties, post-menopausal & insulin resistant – genetically predisposed, I have been told. I fit the profile of a fat burner (no cravings, can go long periods without eating, can exercise on an empty stomach). But I’m still unable to shift the rolls of fat around the middle. I’ve been primal for 12 weeks and no change. What else could be wrong?

    1. Ajay, I have a similar situation. I go by the book, but have been stalled for five years. I’ve been advised to cut my protein intake first, then cut calories, but not below a thousand. I shed sixty pounds and have sixty more to go.

  35. A month ago I was injured and had to stay with my brother and his wife. Theirs is a Weight Watchers household. While I drew the line at grains, I ate basically the same food but just had my eggs cooked with butter. I lost another 9 lbs in 16 days. Now that I’m back on the road and eating primal, I’ve lost another 2 lbs. 11 lbs in June! Part of that loss might have been muscle, but It’s come off my waistline. My poor brother is 5 lbs from goal and crabby and hungry all the time. I can IF for a full day with no hunger and he gets the shakes about every 3 hours. I am a fat burner who can now process variable carbs easily. It doesn’t mean I load every day, but I can eat more carbs occasionnally without destroying my fat burning adaptation.

    1. TruckerLady, how old are you? I want to guess you are pretty young to lose so easily and then, be able to process carbs sometimes, also easily.

  36. Cool post. It’s nice to have a little checklist to refer to like that. Even when I ate higher carb, I wasn’t really a beeyatch when I went long periods of time without food — can I give a shoutout to my parents for being fat adapted folks right off the bat? 😉

  37. what a stupid article….if the writers cared about there audience at all or had half a brain, they would point out that changing from primary reliance on carbs to primary reliance of fats is one of the adaptations that the body makes when it becomes accostomed to exercise.

    1. You know, if I was unable to correctly spell ‘their’ and ‘accustomed’, I wouldn’t accuse others of having less than half a brain.

  38. I’ve been going primal for about 5 days now, and I don’t think I’m fat adapted at all. I was STARVING after a meal of steak and vegetables. I have PCOS with insulin resistance. Is it possible that it might take longer for me than some to become a fat burner because of my insulin resistance?

    1. Give it more time. It could take a couple of weeks or more for your body to switch over. Patience, not panic. It will happen.

    2. And if you’re hungry, have a snack! Nuts or fish or some avocado, something filling. I was hungry a lot at first, too. I think this is normal. Eventually, you will adjust and find what works for you.

  39. the article is very misleading, and constructed to sell their particular diet. while i happen to agree that the paleo diet is the healthiest, but biggest point is that your body adapts to being more fate burning when you do regular cardio exercise…the more endurance, the more you rely on fat burning. if these people had graduate dgrees in exercise physiology as i do they would know that…a half truth is a lie. this is a really stupid article by stupid people written to manipulate the audience that reads it. the kind of food you eat plays little role in how fat burning you are.

    1. That doesn’t even make sense… I don’t have a Graduate Degree (so sorry to have an opinion) but if the only fuel available were fat then wouldn’t the beautiful intelligent complex machine that is my body figure out how to burn it???

      It seems to me that how you eat would have to effect what kind of fuel you are burning.

    2. debbie-you’re being kind of rude, here. One of the things I like about MDA is the wide variety of responses you get from lots of intelligent folks from around the world. People disagree with Mark and with each other all the time, but it usually seems to be more of a debate /exchange of information rather than argumentative. If you have some insights to share, I would certainly be willing to read them, but please be a little more respectful.
      As to selling something, yes, Mark does sell stuff. Both he and the worker bees need money to live on if they’re going to spend time doing this wonderful blog. That being said, this blog is free. Anyone can come here, get the info they need to change their life and never have to shell out a penny. I don’t think you can count this as manipulation.
      Lastly, it may not matter to you what kind of food you eat, but it does for me. That’s another thing I like about this site-Mark admits up front that not everything works all the time for everyone, hence the emphasis on journaling and self experimentation. I’ve been through many diets; all had me eating “heart-healthy whole grains” in varying configurations. All failed to keep the weight off. I also had an incredibly hard time resisting cheating. Having gone cold turkey off grains when I started eating primally, I spent a truly miserable week, then my carb cravings went away. I was sick with bronchitis at the time (yeah, I know Mark said to wait until I was feeling healthy before starting the program, but here I was with an unexpected break from work; the timing was just too perfect…), so I can assure you I was NOT doing any cardio, yet I still lost weight. Can’t cardio if you can’t breathe right!
      I have, in fact, gained so much energy that I actually Want to exercise, a situation that has never obtained for me on any previous diet I tried. Obviously, since we do not have a 100% obesity rate in this country, some people tolerate carbs better than others. If that’s true for you, then fine-for you. I, however, will probably always need to stay low carb and grain free to continue getting and then remaining healthy.
      So please, think what you like, say what works for you, disagree all you want, but please, please, please-stop with the insults. Thank you.

    3. As I’ve gotten older and wiser, I don’t pay much attention to whether someone has a PHD, or if an organization has a bunch of PHD’s on it’s staff. Probably half the doctors are spouting B.S. to their patients with chronic illnesses, and I’m convinced that the American Diabetes Asses, and The American Dietetic Asses, are pretty much that…asses.

  40. I also have PCOS, and I think I’m getting there as far as becoming fat adapted. I actually just realized my husband and I IF without even realizing it today, 15 hours. I am really impressed with how it has helped with my high and low energy swings, because they don’t exist anymore! I know that was caused from the insulin resistance. Great post, I was actually looking for a ” checklist” for being day adapted on the website the other day. Now that I have read it I’m excited to know that I’m getting there! 🙂

  41. I can concur with those having issues with ‘bread’ — my wife and I love the stuff but she is wheat/gluten intolerant so its largely omitted from our diets on that basis alone.

    Lucky we aren’t ‘meat’ intolerant 🙂

  42. Is it a problem if I am too keto??

    I am definitely fat adapted (3 months primal now, and no 80% rule use as yet) and according to my FitDay tracking I am averaging about 45g of carbs per day. I have been losing 1kg per week on about 1400 calories per day, with no effort at all, IFing regularly with ease and doing fasted workouts often.

    Should I be concerned about my carb intake?

  43. I must be doing something wrong! I find have to eat every couple of hours or I’m starving. I went primal/paleo severals months ago; meat, fish, fruits, veggies, nuts, ton’s ‘o water, lost a few pounds in the beginning then stabilized. 6’1″, 175 – 180lbs, 54 yrs, walk about an hour a day, some yoga, heavy lifts, but food wise, I could eat all the time! Go without a meal? NOOOOOOOO!

    What up? Any ideas?

      1. i second that…it is amazing how long good fat will keep u satisfied:)

    1. Maybe with your height and weight, your activity level demands that you eat more.

  44. I find that my status as a fat burning beast improves over time. Before this diet, I couldn’t exercise without a constant steady stream of incoming food. (So debbbie, you are so wrong you should tear up your worthless master’s degree.) I couldn’t be hungry during exercise without also losing energy. And I was always hungry during exercise.

    After I finally got over the carb flu and felt adjusted, my energy quality improved so much. I could exercise fasted and without snacking and lose no energy or strength even when feeling physically hungry. The freedom of that has been amazing.

    I still have that freedom now, 11 months since starting the diet, but now that I’m leaner and stronger, I do have to eat a lot more food once more. I don’t have to snack or carb load to keep up my energy level, and I still maintain energy even when hungry. But I do get hungry a lot more now than when I was actively losing weight, and I do have to EAT when I’m hungry.

    I wish I could get another 10lbs off me, but I continue to see improvements even without additional weight loss, so I’m happy for now.

  45. I wondered if something was wrong with me that I can go without eating for a day before getting hungry. The only discomfort I have from not eating is tolerating peoples reactions. Most are so adverse to this practice I no longer tell anyone when I do or don’t eat.

  46. Does anyone know what effect artificial sweeteners have on fat adaptation, if any? I’m struggling to kick my diet soda habit, and was wondering if that’s part of why I’m not as fat-adapted as I think I should be by this point.

    1. Bingo. Lose the artificial stuff. Every time I felt a craving for sweets I drank several gulps of water and eventually the cravings subsided. Magnesium helps, too.

    2. Check out mercola.com and search on artificial sweeteners. They are truly problematic. Splenda (sucralose) is a kissing cousin to DDT. Lots of folks have reported multiple symptoms, one of which is leaky gut syndrome, worsened by use of these sweeteners.
      I don’t remember reading anything on how they affect fat adaptation , but there’s enough bad things to warrant giving them up anyway.
      A product you might look into is called “Just Like Sugar”: calcium, Vit. C, orange peel flavorings and ground up chicory root. Tastes like sugar, though I have no idea why with that ingredient list.

    3. Why don’t you make your own soda?

      Artificial sweeteners are deadly poisons. Diet Coke is actually worst for your health than regular Coke.

      You can make your own SWEET soda without sugar. Stevia is a natural sweetener from the plant stevia (which you can buy in garden centers too). If you buy a sparkling water machine like Sodastream (I have one, it’s awesome) you can make sparkling water. Add a few drops of stevia extract (available at Whole Foods) and lemon juice, voila. You have yourself an all natural sweet soda (lemonade). Added benefit, no waste (no soda can and plastic in the trash).

  47. ok so i tick all the boxes for being fat-adapted-lots of energy, can exercise first thing before eating at all, no cravings, etc etc-I do get hungry 3 hours after breakfast but don’t need carbs in any form-however I haven’t lost any weight after 5 months, yes I’m female and read that others have similar problem despite all the science… so i do fell healthy and admitedly really only 12-15 lbs to lose BUT what’s the deal???

  48. fasted this morning, walked 3 miles with my dog, ate salmon, turkey and primal trail mix for lunch, hiked 3 miles, tri-tip, grilled carrots & bok choy for dinner…fat adapted FEEL AWESOME!

  49. * three hours without eating? CHECK
    * skipping a meal an exercise in futility and misery? NOT WITH ME
    * enjoy steady, even energy throughout the day? CHECK
    * midday naps pleasurable indulgences, rather than necessary staples? CHECK
    * exercise without carb-loading? CHECK
    * headaches and brain fuzziness passed? CHECK

    It is official: I am fat adapted!

  50. I eat once a day. I shop for gorceries while hungry and not pick up unwanted or unneeded food.I don’t work out but I do work a very physically draining job all day without eating. I manage to keep my prediabetic glucose levels within a normal range.

  51. I’m into week 2 of going primal. I’ve had no problem dropping the grains – except when out and I become hungry (I’ve taken to putting a meat muffin in my handbag for thease ocassions). I’ve dropped all sugar except for a tiny amount in my morning coffee without any real dramas also. I have experienced no brain fuzziness or low energy levels yet. Next week I start my final nursing prac (high performance expected) and I’m really concerned about it hitting when I need to have my brain and energy levels working really well. I also don’t feel like eating at 4am when I get up. Do you have any advice on what I could pack in my lunch to combat this if it strikes at work?

    1. fat…eat fat…i like coconut milk mixed with berries very filling…just smash them a bit & let them sit…chill eat…or an avocado or nuts but coconut milk & coconut oil keeps me satisfied for hours a 4am smoothie w/coconut milk & oil would keep u good for a while..:)

    2. After 2 weeks it might not happen at all. Didn’t for me. Eat more salmon or sardines. Awesome brain food 🙂

    3. Catherine-I’m an RN, work twelve hour shifts and sometimes I get forced into IF purely due to work load.(Welcome to nursing!) Couple weeks ago, I got floated at three pm to another floor; hadn’t had time to lunch earlier, then got five new patients on the new floor, so never got to take a break there, either. Had breakfast at 0630, nothing but water and green tea all day, then ate my lunch at 8pm after my shift. That was about 4 weeks into eating primally. One of my afternoon patients sent my manager a very nice message about my care of them, so I must have been doing well!
      I would guess if you haven’t had the low carb blues by now, you may luck out and avoid them altogether. However, I will tell you that I am faster and much more clearheaded since starting PB. I will be aware that I am hungry and it would be nice to eat, but no longer have the cranky, fuzzy-headed, headachy kind of feeling I used to get.
      I do, however, throw some beef or turkey Nick’s Sticks in with my lunch, or some sausage sticks if I can find some without a ton of crap in them. For me, having some fat with my protein if I do snack is vital. With your practical coming up, I wouldn’t even worry about being picky-just get something fatty and high protein to get you through next week, then work on better food sources afterwards. Hard boiled eggs, sausage sticks, beef jerky and macadamia nuts are some of my go-to snacks of choice. There’s also a wonderful product called coconut manna, which is ground up whole coconut, includes the oil; a small tuppertainer with a couple tablespoons of that and some squares of 70%+ chocolate is very Mounds bar-like and is mostly straight fat with a couple grams of sugar.
      Good luck with your practicals and welcome to nursing!

      “Save one life, you’re a hero. Save a hundred lives, you’re a nurse!”

  52. i must be fat adapted…4 most days i drink coffee with coconut milk & oil & thats it until somewhere between 3 & 5pm & i am not hungry at all. on the 4th i have smoked a turkey/ribs & fixed my family their faves candied baked beans, mac n cheese, corn salad …& brownies…never felt the urge to cheat and they all boo’d me because i forgot the garlic bread…i never even “thought of bread” thats awesome

  53. Karen-
    My wife has candida and is really frustrated with the time it seems to be taking to get rid of it. Mind if I ask what your treatment for candida is? We are both eating primal, and while I feel fantastic and am burning fat like crazy, she is still feeling really crappy and is really questioning this way of eating for her body.

    1. Hi Jason. My naturopath prescribed me a 30-day course of nystatin, which she says is as effective but kinder to our systems than the more mainstream anti-fungals. I also followed her version of the candida diet (there are many variations) for 6 weeks, which overlapped for the first 4 weeks with the nystatin. Since I was already eating primal by the time I started treatment, the only real changes I made for those 6 weeks were that I eliminated all alcohol (I’d been having red wine occasionally) and dark chocolate (out of extra caution), and I cut back on fruit.

      I hope your wife is seeing a doc who thinks about her as a whole person and takes all symptoms into account. I assume that since you say she has candida, she’s officially been diagnosed, but even still there could be other issues that are impeding her progress. In my case, I also treated adrenal fatigue and thyroid along with the candida. It’s hard now to say exactly what made things begin to turn around for me, but it’s possible the whole combination of efforts was necessary.

      I hope she beats whatever’s got her system stuck soon. I know I’m just N=1, but primal has definitely been a key aspect of my new found quality of life. Best of luck and health to you both!

  54. My vanilla coconut milk has 64 grams of sugar in one half gallon. Is this sugar bad for me and something I should avoid?

    1. There is better coconut milk out there or you can make it yourself from shredded unsweetened coconut. I do. Info on how to do this is on the web with some searching.

    2. I use unsweetened coconut milk – not the canned stuff…much much less sugar.

  55. If one has fatty liver, would one have to wait until that is resolved (via eating low carb primal as Chris Masterjohn points out in this link: https://chriskresser.com/chris-masterjohn-on-cholesterol-and-heart-disease-part-3#comment-22270 ) before fat-burning of adipose tissue can commence effectively?

    Here is my post which goes into detail of my current dilemmas:

    Short story is that I’ve been eating low carb Paleo and doing IF 16/8 to 20/4 the last few mos. Although I have lost some weight and bodyfat (was 24%, now 19%) and I am far from my goal of <10%. It is hard to pinpoint what could be impeding my goal. Fatty liver comes up as my first suspect.

  56. Thanks so much for this post, Mark! It really helped me see how far I’ve come myself, and how far my kids have come since falling into step with a fat adapted lifestyle.

    Cheers! Hope you all got to play today 😉

    1. I was curious if a fat adapted child has less meltdowns? Do they not get cranky when hungry? Notice any difference with your children?

      1. I’ve noticed much better behavior in my kids, ages 5 and 6 since ditching grains. They now eat bacon and eggs, sausage and eggs, nuts and dried fruit or something else with protein and fat for breakfast. Most days they don’t stop going full speed until around 2pm when I have them eat lunch. No need for snacks every 2-3 hours as during their carb-heavy snacking days in daycare. Now they know when they are actually hungry and politely ask for something to eat. No crankiness. No whining. No tantrums. It’s wonderful!

        1. You should drop the sausage and bacon immediately though. These are the worst processed meat you can find and usually contain potassium nitrates which cause digestive problems and sodium nitrates which cause a variety of cancers. Most hams are also loaded with these chemicals that help preserving the meat and also keeping it pink, otherwise your ham and bacon would be gray, which is how it should look if you want to have it.

        2. I happily found out Whole Foods is selling bacon not processed with added sodium nitrate. I got some, delicious. But, it costs $9/lb, while the Oscar Mayer junk costs $4/lb. You get what you pay for I guess.

          It’s a nice treat once in a while but IMO, I’d rather spend $9/lb on buffalo ground meat.

  57. Hey guys
    I’ve only just started the Paleo diet and it already feels good!!

    Im confident I can drop body fat as you all have but naturally being so tall I dont exactly look well (buff) so lean.

    Carbs have allowed me to build a little more muscle which was good but way too much bodyfat.

    On the paleo diet how do I build muscle?? Is it basically switching from carbs to very high protein and ensuring I eat enough / or more calories?


  58. David,

    “Vanilla Coconut milk”- Not very primal, i would think. Look for a variety that’s not flavoured. Organic non flavoured would be best, in my opinion.

    God knows living right is difficult for me. I live in the middle east, and organic stuff costs me an eye, arm and a leg.

  59. Just finished readin ‘The Art and Science of Low Carbohydrate Performance’ by RD, Jeff S. Volek PhD and PhD, Stephen D. Phinney MD

    Quite an interesting book although a lot of their work is still in progress.

  60. I’d love to see Mark publish a follow-up to this talking more about the process we should expect.

    I admit that every couple months I crave bread or baked goods. After 3 years, I think I always will.

    When I do indulge, it still tastes great. (Like nothing else out there.) I don’t feel great afterwards though. I don’t notice any progress off this cycle.

    Is this normal? Will it change if I keep at it?

  61. i started the PB in january, first step was to cut sugar, replaced it with honey. now i have cut that too and find i don’t even like eating sweet things. cutting grains was difficult, but 6 months in and i am mostly grain free – if i do eat pizza or pasta etc, the next day is somewhat uncomfortable so i only do it rarely when friends want to go to the pizza shop once every few months. the biggest thing i noticed is that recently i am going to the gym for an hour, or riding 20km on a daily basis… all without having eaten anything. i have more energy, don’t get hungry or fatigued mid session and am building strength and endurance at a rate i didn’t believe possible.

    i pretty much eat meat, fish and vegetables, with a bit of fruit and nuts depending on the season. since January i have lost 12kg with little effort, but i still drink too much booze due to some personal reasons (relationship related depression – we have all been there)… if i could drop that the last 5kg around the middle would be history. another side effect of going primal has been that i do not get sick any more… seriously, everyone i know gets the flu a few times a year and even getting sneezed on by some sickly grain junkie in the street does not pass on the virus.

    this site has changed my life, just gotta deal with the depression and stop drinking beer and i will be the finished fat adapted product…

  62. Okay, I think I am extremely fat adapted, low carb, 2 to three meals a day. So why do I look more like the guy on the left than the right? I feel good, lots of energy, but weigh too much.

    No, i am not eating candy in my sleep.

    1. I hear you and I’m the same. It’s funny how comments like yours get overlooked. You say that something’s not working, but I don’t see any helpful advice for you. Just everyone else patting themselves on the back. Don’t we all want success? It’s easy for others to think people who are overweight are just weak, or that they tell lies about their self-control or discipline. But what if they try just as hard and still nothing changes?

  63. I’ve been following this faithfully for almost a year… It has changed my life! I’ve lost about 100 pounds and have about 20 still to go. People always ask me how I’ve done it (if they recognize me at all!) and I first U replied “I gave up wheat and sugar” which sounds like a sacrifice which it’s not. I now say “I cut out the foods that were killing me” and imagine myself as a proactive swashbuckling pirate protecting myself. Puts a smile on my face… thanks Mark!

  64. I’ve been following this faithfully for almost a year… It has changed my life! I’ve lost about 100 pounds and have about 20 still to go. People always ask me how I’ve done it (if they recognize me at all!) and I first U replied “I gave up wheat and sugar” which sounds like a sacrifice which it’s not. I now say “I cut out the foods that were killing me” and imagine myself as a proactive swashbuckling pirate protecting myself. Puts a smile on my face… thanks Mark!

  65. correction, at first I replied… apparently my coffee hasn’t reached my fingers yet…

  66. Do you know much about how your body works when breast feeding your child?

  67. I’m not quite sure if i’m fat adapted :s the problem is, I started eating Primal a while, and I lost a lot of weight. But here’s the catch, i’m only 18, and to begin with, I wasnt that heavy. Now I’m pretty skinny and my mom keeps telling me that I’m underfed.

    What I’d like to know is, is it normal to lose noticable weight when you go primal, even if you werent THAT heavy to begin with?

    Now, because of a lack of support within the family (they understandably think that eating primal is rather expensive, which it is) I have found myself reverting back to my old ways. I dont eat bread a lot, only about a couple of sandwhiches a day, and i make sure those are loaded with protien and fat (100% natural peanut butter, and “heart healthy” margarine)and my job requires a lot of physical labor (landscaping).

    what can I do to make sure that I dont get too skinny, and is it alright that I eat some carbs?

    1. Get rid of the margarine and stick to good quality butter. Try increasing carb intake from vegetables such as sweet potato – with your activity level you can probably even get away with potatoes, pumpkin and carrots as well.

  68. Good timing as I’ve been wondering how I can tell when I’ve become a fat burner. Fortunately, I meet all the criteria above. I still can’t shake the feeling that it doesn’t seem “painful” enough. I eat very well (and don’t need to starve myself…shocking!!!). I train hard but don’t kill myself as I did before. I am only hungry when I truly should be and can exercise at a high intensity without needing to fuel beforehand AND I’m not starving afterwards. As a side effect, I’m leaner than I’ve ever been in my life. Seems too damn easy, thanks Mark!!!

  69. This article fails to address the most obvious topic of how to train one’s body to become able to digest fats as opposed to sugars. I already know I’m a sugar burner, but how do I become a fat burner?

    1. Stop eating sugar. Stop eating grains that your body converts into sugar. Lift heavy things and move slowly often.

      I don’t mean to make it sound so simple, but it really isn’t very complicated. If you are new here and haven’t read much of the site yet, spend some time under the “Start Here” tab. Thats where I started and I didn’t even read all of that info in order. I read the things that jumped out at me first, because those topics answered my most burning questions. Do the same and I’m sure you’ll find the answers you need/want.

      Good luck!

  70. My Dr. suggested I purchase, read and follow
    “Dr. Gundry’s Diet Evolution” .
    Dr. Gundry is a heart surgeon, inventor of a special heart pump for surgeries and a former sugar burner.
    HIs book is a 3 Step Program of Reprogramming your
    genes and then maintaining your new genes.
    Very exciting stuff as Mark’s stuff.
    The problem with any program as it must become a lifestyle, NOT a diet.
    Dr. Gundry varies with Mark in the AMOUNT of protein eaten in any given day. Dr. Gundry prefers a lower animal protein while higher or bulk of your energy comes from plants, nuts, and minimal fruit (whole fruit) not juices.
    BOTH programs I have done.
    Both are excellent programs.
    However, if you have unknown health issues like I did, Dr. Gundry’s along with my Metabollic testing showed I have a very HIGH iron count. Hemochomatosis from my Swedish ancestors so the high eggs, beef, etc. was my enemy on the simple Palio diet.
    I ENCOURAGE anyone who may have northern climate ancestors to have their blood tested for Hemochomatosis.
    HIGH IRON is deadly for your organs and ultimately your longevity.

  71. I discovered this informative website several weeks ago. I have what will be a ridiculous question for a website on the Primal Blueprint: how can a vegetarian follow a fat-adapting diet? I limit carbs as much as possible, other than fruit. I eat lots of nuts and seeds, veggies, Greek yogurt, cheese and soy milk. I have lost 10 lbs in the last 3 mo by limiting carbs. Any suggestions for me and other vegetarians? (I have been a vegetarian for 31 yrs and there is no possibility of me ever eating meat/seafood again.)

    1. I am a former vegetarian (15 years veggie), and although I now eat meat, I do believe the Primal Blue Print can be adapted to a vegetarian diet as long as you are willing to eat some animal proteins and fats, such as eggs and yogurt.

      Eat lots of eggs! Eat lots of good fats like coconut oil and olive oil and avocados. Ditch the grains completely. Have some raw cheese and butter and whole milk yogurt. Get rid of the soy milk and all soy. Eat lots of veggies and some fruit. Eat some nuts, but not a lot. If you won’t eat eggs, eat some beans prepared by traditional methods – but try to convince yourself that eggs are healthy and can be raised by ethical farmers in an ethical fashion and eat those instead.

      Good luck.

  72. I used to be fat adapted before I became pregnant. Now I really am not sure because I feel hungry a few hours after and cannot go with skipping meals. So not sure if I’m no longer fat adapted of whether it’s just my body doing strange things!

  73. Sometimes I want to skip meals b/c I am not hungry or I am fat adapted… but I can’t get over psychologically not having 3 meals a day. And I fear other people saying “you’re not eating” or something like that… any other girls have this issue?

  74. The nerdy scientist in me must point out a correction: I would replace respiratory quotient (RQ) with respiratory exchange ratio (RER). RER refers to whole organisms, while RQ refers to isolated mitochondria. RQ would be near impossible to measure in humans (without cutting out pieces of them, homogenizing those pieces, blah blah biology wet lab stuff).
    Also, RQ can never be >1, so you definitely meant to say RER.
    Also, RER can be measured noninvasively. I do it all the time.
    Other than that, great summary!

  75. You are the man, Mark! You have changed my whole outlook on life, nutrition, and exercise.

  76. Getting started, about 4 weeks in, I have doubled my eggs, meat and fish proteins intake (from being almost vegetarian), increased a bit fat in my cooking and cut in half grains (cereals and bread). I have not lost weight yet (I’m only 15Lbs over) but I have lost some belly fat and gained a little bit of muscles.

    I’m no way eating a pound of bacon in the morning like I could read on one of these threads, when we eat meat, my wife and I each have a half (typical size) grass-fed hormones-free steak with vegetables (sometimes a grass-fed burger on buns) and that is way enough food IMO. I’m pretty sure Groke was not having a pound or two of meat when he fed himself.

    I’m not completely eliminating grains because I find gain-less diet extremely boring; I make my own delicious bread the French way and have a homemade pizza 100% from scratch or a quiche once in a while. Very rarely sweet stuff however such as cookies, cakes and ice cream, never any soda, never any manufactured food that contains corn syrup and MSG an avoid food potentially containing GMO’s.
    For breakfast instead of a half cup of organic cereals in the morning I just have 1/3 cup on organic rice milk to boot my brain up . Later in the morning I have fatty food, I eat a quality boiled egg (from a local farm when I can) and snack on about a 1/3 cup of nuts (walnuts, almonds and Brazil nuts) with a cup of coffee or two and I don’t get that mid morning drop of energy anymore.

    Overall I feel more energized all day and less tired in the evening, but if I grab a beer and snack on crackers or chips, I can feel my energy level crashing within minutes and get bloated.
    Yesterday I went kiteboarding for almost 5 hours non-stop then refueled with a half medium rare grass-fed steak and well oiled (olives) delicious mixed salad (lettuce, carrots, olives, dried tomatoes and a few black beans), and felt great.

  77. This makes interesting reading and explains something that I’ve noticed since switching away from sugar – a couple of times when I’ve been busy this week I’ve missed lunch and simply have not noticed it, whereas in the past I would be starving my lunch time ..

  78. I do not eat more whole grains, but this does not mean that if a baker of bread comes out smelling like I will not eat it because I know the problems that brings.
    To lose weight I have removed the binge eating of dried fruit.
    Also a week I started fasting for breakfast (I had tried a few months ago but apparently I was not ready because I’ve eaten at mid-morning), I feel good and go on without hunger until lunchtime (and I realize that often for lunch I eat more to habit than true hunger)

  79. Headaches, grumpiness, fear of running out of steam 40 minutes into my workouts… I try to eat as primal as possible, but how do I make the transition?

  80. Considering I skipped meals all my life, I’d say I’m pretty fat adapted. Food was never an issue for me… problem is I’ve lost about 2 kg since going primal and I was already borderline underweight. No amount of weight lifing is helping me gain, and trying to overeat primal carbs has been a disaster of fruit and potato induced sugar rushes and crashes.

    Meh, I’ve decided to accept the fact that I’ll always be a little underweight.

  81. How do you train your body to be fat adapted? I’ve read the PB and have been eating the primal way for some time but I don’t think I’m fat adapted yet hence still having difficulty at intermittent fasting.

    I’ve also found it difficult completely excluding starchy carbs so I included plantains as my only starchy carbs for no more than one meal a day.

    Are there any special techniques one can use to become fat-adapted and how long does it take?

    Any posts here you can point me to? I’ve searched but can’t find anything with specific guidelines. Thanks.

  82. I’m still in constant awe of the difference fat burning makes to my overall experience of life. When I gave up smoking many years ago, I never experienced that “liberation” feeling people describe, but being fat adapted? Oh man, you just don’t realise how food dominates your life until it stops being the case.

    When I first read your suggestion of fasting “not IF but WHEN”, I know subconsciously I wrote the idea off as not really being for me: I was almost constantly hungry, so the idea of an unplanned fast seemed impossible!

    But sure enough, only the other day I walked six miles in a fasted state to a pub which had a pretty unappetizing menu for a primal eater. So I had a nice glass of water and walked six miles home again without giving it a second thought.

    Utterly liberating – thank you!

  83. Great article. I have been primal for about 2 months now, and for the past 5 days was in the mountains on a trip with friends. We hiked almost daily, and in the morning I would have tea and maybe some jerky or an egg, then we’d go on a 5 or 6 mile round trip hike. I would eat a few nuts or some more dried beef on the trail if my stomach growled, but I did not feel that howling, must-eat-now-or-die hunger, I wasn’t shaky, tired, crabby or anything like that. Coming back to camp for lunch after all that exercise sometimes I wouldn’t even be hungry, and this was a revelation to me. I never knew this was how my body was supposed to feel! It’s such a relief not to feel like I’m being controlled by hunger or planning my day around food, to know that even if I feel hunger, I am not in imminent danger of turning in to a raving b***h.

  84. What is the word of Fat-adapted and BONKING?

    My body is adjusting to a new way of eating and I have noticed that I can cycle longer in a fasted state. But I do not know how far I can go before I hit the wall. I have a 56 mile ride planned Saturday and am afraid to try it without a carb-y dinner on Friday.

    Please HELP. Thanks!

    1. If you can, drink a coke on the ride. Seriously, around the half way point. It won’t hurt your paleo. Later.

      1. Come on, you can’t be health concious about your diet and recommend a coke! There’s better sugar than a coke… coke is one of the worst beverage for your health you can have. Not talking about the sugar but all the chemicals and acids it contains. If you need a sugar jolt, make your own lemonade with organic agave sugar or (real) maple syrup, sparkling water and fresh lemon juice. It taste good too.

  85. I’m fat adapted. Yup, I’ve adapted to being fat……Joking of course, getting more paleo by the day. Goal weight, 190.

  86. I’m a sugar-burner. How do you become fat-adapted? I’m assuming it’s possible to switch from one for the other but what do you have to do to get there?

  87. HOLY HANNAH, I’ve been researching this on my own incessantly. I’ve been 95-100% primal for the last year. I have no problems with it, I love it. I’ve been faithfully doing Crossfit 5-6 days a week for 8 months and I love it. I dont have a thyroid, 1 year on Armour. However, I cannot lose body fat to save my life. I do body comp tests every 6-8 weeks and I’m simply not losing fat. I am gaining muscle though.
    I can’t skip meals, Im hungry and headachey more often than not and rarely get through a day without a nap. PLEASE HELP! IS THE MISSING THYROID THE KEY?! I’m beyond frustrated!!

    1. Hannah-Still working on issues myself, and quite frankly, the hormone stuff makes my head spin sometimes! Good for you to be on Armour rather than the usual T4 only/Synthroid crap. That being said, have you checked your other hormone levels? Vit. D? I’m still learning, but my doc and I are working to get my hormones back into balence. We’re starting with cortisol, since mine is at the extreme low end of what CW says is normal. My doc said no use to try and get thyroid fixed until cortisol and ACTH are back up.
      Interesting take-away, she told me that Armour and one other desiccated thyroid med she used to prescribe now have additives like corn and wheat! She’s currently looking into one called naturthroid ( I think) to see if it’s a cleaner version.
      So you might consider checking some other labs, as well as the content of the Armour you’re taking.
      There’s a website run by fellow thyroid patients called Stop The Thyroid Madness (STTM) that has lots of info on it. I’m still slogging through it, and the book of the same name; they are Sometimes a Little over the Top with their adjectives, if you know what I mean, but the info is very interesting. Hope this helps, Hannah. Good luck!

    2. I’m still new to this way of life, but I found I lost the most weight when following PB fitness. I’m presently in the middle of a trial of a 90 day cycle of p90x and I’m losing less, if at all. So maybe try out dropping the crossfit and following PB fitness. Also, try tinkering with the amount of protein, dairy and fruit you are eating, one at a time to discover if one of these are hindering you.

  88. I used to be hungry CONSTANTLY! Until I hit 30 I could also eat constantly and not gain, but then came a quick 25 extra lbs.
    It took me seven years of diet/ exercise to finally get to a system that melted lbs without exercise:
    I eat five-six hours each day only. Example: am smoothie of cultured coconut milk, hemp hearts, raw protein powder, kale, frozen berries and green tea. The rest of my eating period is 80%raw fruits and veggies.
    This way of eating allows me to sleep on an empty gi tract so that all of my restorative sleep is just that, no energy towards digestion/storage.
    I haven’t been hungry in months and have lost 30lbs over the last two yrs!

  89. I’m pretty certain I’m a fat burner now having switched to low carb 9 months ago and lost 34lb. I prefer to exercise on an empty stomach – preferably first thing in the morning and at least 2 hours after eating. No longer crave carbs and when I tried my first bagel for 6 months last week I no longer liked it. My trouble is chocolate and I have to factor that into my day but certainly for me the hunger and cravings are largely psychological rather than physiological. When I’m bored or tired or stressed I crave sweet things, when I’m busy I can go for hours without thinking of food. Its so hard to separate the physiological hunger from psychological “hunger”.

  90. In correction to the above – I prefer to exercise 12 hours after eating not the 2 hours stated.

  91. Mark,

    Great post! I’ve always felt better energy levels as a fat burner and just in general healthier and less sluggish. Adapting to a more Primal diet and practicing intermittent fasting has definitely helped me make the transition.


  92. I have been primal since March. Lost approximately 25 lbs of fat and gained about 10 lbs of muscle. I calculated this through charting body weight, tape measurements and Accu-measure pinch test for body fat percentage. It is very important that all of us not to become so fixated on total weight loss alone. This is not a true picture of what is happening to our bodies.

    In addition, the same simple rule applies to the primal lifestyle, “Calories-in versus Calories-out.” If you want to reduce body fat, you must create a deficit!!!! Just because you are a fat-adapted, primal monster, it does not mean you are free to eat 3,000 kCal in one day when your daily requirements are 1800 kCal.

    For me, I use Intermittent Fasting (IF). I know for some, this is a scary concept, but if you desire weight loss, while keeping your muscle, this may be an approach for you. Mark has many posts on IF so I will not go into detail but I will let you know it worked for me. So how do I know I have not lost muscle while IF-ing? I charted my strength increases over the last 4 months. Increase in weight lifted and reps obtained went up 48%! Yes, this is with eating only once every 16 to 24 hours and no, I did not feel like I was starving. As long as I put in the “primal” only food, I had no hunger pains.

    So as they say, proof is in the pudding!

  93. I LOVE this article, but it makes me think I am doing something wrong — I have been primal for 2+ years and I no longer crave refined carbs (I used to have a HUGE sweet tooth). My cravings now include berries, dates, and nut butters, which I limit because I could eat a whole lot of these things. Constant hunger is still an issue though. I am def. hungry every 3 hours. I used to blame my very high activity level, but is this fair to do? Or am I doing something wrong?

  94. Great article, Mark! Thanks for all of your continued efforts to disseminate information like this in a way I can use to talk to my friends. It’s one thing to know all the chemical processes that go on in the body, it’s another to put it down in a way that makes sense to people who don’t, and you’re a master of that.

  95. I’ve only been primal for a month, but I’m pretty sure I’m fat-adapted. Four meals in the last three days, one each for the last two days (a big-ass salad) and 24 hours between those; a four hour walk yesterday and a four-mile jog this morning, both before my one meal of the day. I had gone 18 hours without food when I went on my jog, and worked out for 5 minutes in the middle `cause I felt like it. Easy.

    My only source of carbs in the last three days has been vegetables. I suspect I’m in ketosis. I basically did three IFs in a row. Virtually no hunger, definitely no cravings.

    I’ll have a small dinner tonight and a can of semi-primal clam chowder sometime in the next 22 hours or so (potatoes).

  96. Hmm, I meet the fat-burning criteria except for the constant need to nap and the brain fuzziness … oh, that’s right! I have a six month old. Problem identified!

    1. Lol, me too! When I first began this I kept wondering why my appetite hadn’t been reduced. Then it dawned on me, duh, I’m nursing a little grokling!

  97. Just finished “The Art and Science of Low Carbohydrate Performance” by Jeff Volek and Stephen Phinney and I too wonder as a previous poster has pointed out if the gap isn’t that tight as suggested in the book. Mark seems to think you can tolerate more carbs and still be a fat burning machine, the book indicates that you have to be at or under 50 grams to achieve optimal fat burning (along with training at or under 65% of your VO2 max). Just began “The Big Book Of Endurance Training and Racing” by Phil Maffetone, will be interesting when I get to the nutrition chapter what Phil’s take on the subject is.

    1. I haven’t read Volek’s & Phinney’s books yet, so I don’t know if this is the case, but it sounds like they are counting “net carbs” (total carbs – insoluble fiber) like the Drs. Eades do, rather than total carbs like Mark.

      Apples and oranges when setting your limits.

  98. I’m 9 months into Primal and I would say I’m pretty close to being fat-adapted. A year ago, if I ate a meal with too many carbs, I’d be shaking and desperate for food within 30 minutes. Now, I eat 1 or 2 meals a day and rarely get hungry. When I do, I usually feel like I’m running on empty instead of shaky and grouchy.

    So far I’ve lost 32 pounds, a steady 0.8 pounds per week, which is amazing for someone with hypothyroidism. It took about 2 weeks for my bread cravings to go away. I returned to eating a little cheese and ice cream since I didn’t feel any different with/without them. Those are my indulgences. I do use “Paleo” replacements occasionally, for baked goods, but it’s rare.

  99. Perfect timing Mark! I read this today after a couple rare days above 150g of carbs and wondering if those cravings meant I could still be sugar-adapted.

    But tonight, my kids and I went to the greenbelt near our house here in Phoenix to play soccer. They are 6 and 9 years-old so our play often revolves around keep-away and their thinking it’s funny for Daddy to chase the ball as far and long as possible. I went about 20-25 minutes kicking the ball around and having them make me do many sets of 50-80 yard sprints. At the end, I wasn’t very winded and felt incredibly happy and energized. As I put my arms around my sons on the walk home I thought, yep…definitely fat-adapted! 😉

  100. “Fat adapted”…”Sugar Burner”?
    I seem to recall Mark saying Metabolic Typing was hogwash and yet he keeps dancing around the same concepts that Metabolic Typing supports. Metabolic Typing definitely supports Primal Blueprint eating for certain types but with even further detail. I love using Marks Cookbooks for clients to see how easy it is to eat whole foods that lean more towards fats and proteins.
    The take away from this post is that everyone is biochemically unique and we need to find what foods and macro nutrient ratios work for each person. No matter what “type” you are, keeping away from processed foods will also keep you away from the doctor.

  101. Anybody heard of Roca Labs Formula? I want to know if the stuff really works. I heard it creates a natural gastric bypass effect so that your food intake is cut by half without surgery. I am definitely a sugar burner.

  102. Just received some lab work back and the urinalysis (UA) showed traces of ketones; the “normal expected value” was supposed to be negative. The remainder of the UA results confirmed that I had a major UTI ( infection), which I had known from the symptoms.
    Now, going over Mark’s list, I think I’m fat adapted-can go long stretches between meals w/ no crankiness, no napping required, have done workouts in a fasting state and felt hungry but fine afterwards, no more brain fog.
    So, here’s my question : are ketones showing up in my urine because I had the UTI, or because I’m fat adapted? ‘Cause if it’s the latter, and you wanted to check if you were fat adapted or not, I know there are urine dipsticks you can use to check and see if you have ketones in your urine and you could just do this at home-no doctor or lab required. Does anyone have any further ideas or info on this? Seems like it might be easier than that the respiratory efficiency test Mark was describing, if it has any validity as a marker for fat adaptation.

  103. Mark
    I’m tired hungry and a complete sugar addict. I crave carbs and rarely eat well. I had a gastric bypass 5 years ago, lost 180 pounds, and have gained back almost 100. I’m tired of being overweight and tired of being tired. I loved this article because it describes me to a tee. My question is where do I start. Seriously! I am ready to get my energy, life and fitness back. I am motivated.

    1. Good luck! It’s a fun journey to start. Go to the start here tab and just start reading and implementing. Consider yourself a science experiment and have fun!

  104. Hi there,

    I have a few questions I was hoping you knowledgable people could answer for me…

    I’m relatively new to this style of eating (had pulses and whole grains before, but otherwise mostly paleo). I feel like I’m some way down the Fat Adapted road – don’t get hungry between meals so much, can train without carbs etc. but I would like to become fully fat adapted. My questions are these:

    – how to accelerate that process? Just continue as-is (reasonably low carb, high protein, moderate fat) or move towards a higher fat diet?

    – what happens when you eat carbs? I am vegan one day a week – will these additional carbs have any effect on fat-adaption?

    – I do bouts of quite intense exercise, and normally eat carbs (banana or sweet potato) straight afterwards – if I am fat-burning, do I not need to do this, or do I still need to replenish muscle glycogen stores?

    Thank you in advance for any advice you many have!

    1. Get an oil lamp. Fill it with protein. Try to get it going. Now fill it with coconut oil and watch it burn baby, burn!

      Don’t be afraid of fat. Fat, as we have just demonstrated, is your fuel. Primal is not high protein, it is high fat.

      If your vegan day consists of vegetables and green leafys with olive oil and/or coconut oil, no problems mate. Consider, however, that one way to eat vegan is to – not eat. How about a fast day instead?

      Consider also the possibility that a vegan day is an affectation. You aren’t actually a philosophical vegan and there is no dietary or environmental reason for it. Let it go.

      Unless you are are engaging in multi hour, multi times a day, intense exercise in a competitive environment there is no reason to even think about your glycogen stores. It’s a complete irrelevancy. Your body will manufacture what it demands. From stored fat. While you sleep. “Worry” about getting enough high quality sleep.

      Note that an Ironman is NOT a multi session intense exercise just because it is nominally three events. It is a single moderate effort.

      If you have a psychological need to eat something try a hard boiled egg.

  105. Mark and all… At our Center, we test our client’s resting and exercise metabolisms using the New Leaf Metabolism Assessment System. We have found it to be extremely important in determining whether the client is “fat adapted” and to what degree. In fact, it does give you an EXACT RQ value that you speak about in your article above and ultimately tells us what percentage the client burns fat versus sugar while at rest. Then, we design an exercise and weight loss nutrition program to help them improve all aspects of their metabolism and lose excess body fat as well. Thanks for posting this article – it truly describes the “real” issue when it comes to why the general population can’t lose and then maintain their weight.

  106. Thanks for this article!I am sugar-addict without any doubt and want to change it.I admit that it might seem really strange, but I don’t know how to do it. Just buy some primal book and start to eat this way? And what book would you suggest? Or should I somhow gradually do it? I would be really grateful if someone would give me a short advice.

    1. As someone fairly new to paleo eating, I would recommend just going for it. There’s enough stuff on this site that you could read here and then just try things; I found Mark’s 21 Days book particularly useful because it gave me specific tasks for each day, which kind of got me started.

      DEFINITELY clear the junk out of your pantry; if you have to get dressed and leave the house to acquire a craving food, you can better resist ithan if it’s just down the hall.

      I really like the stuff on this website, the rest of Mark’s books, Loren Cordain’s books, Robb Wolf’s book and It Starts With Food.

      Good luck !

  107. Ahhh, thanks. That was just what my brain needed after reading someone’s blog post “Ten Reasons I’m Not Primal/Paleo”.

    “……paleo is a fad with no evidence supporting it……”

    She even adds links to one of Mark’s interviews.

    Next blog entry you see CheesyGal and her grain fed mid-western hubby and think, “Gosh, I’m looking at two fairly big reasons why I eat primal”.

    Keep up the good work and thanks.

    1. Millions of years of evolutionary eating: fad diet.

      A few decades of eating according to propagandized by marketing and political concerns: standard diet.

      Sometimes the stupid is so great the only thing you can do is point and giggle.

  108. Something to note for people who still consume a fair amount of carbs, like me – if you are feeling constantly hungry, check your water intake. Glycogen stores require as much as 3g of water to store 1g of carbs, so if you are dehydrated all the carbs will leave your body without filling up your glycogen.

  109. Great article. The one additional thing I would like to add regarding there is no “fat adaptation home test kit.” You can easily test blood ketone levels (bohb) via an inexpensive blood glucose and ketone monitoring system. I read that measuring one’s blood is more accurate than via a urine sample, so I ordered a testing kit with some blood ketone test strips and watched how my bohb levels are around 2-2.5 mmol after I became fully keno adapted (for me, I define that as <= 50 grams of carbs per day max — usually in the 40s for me). The Volek/Phinney book on LC performance was very beneficial for me. I tend to look at any home test kit like this as more of a validation tool that I am in the general range of being in a keno-adapted state, rather than over-analyzing individual test result strips down to the tenths.

    I have found the benefits of LC to be fabulous. I'm training for my first marathon, and I can wake-up early, no food/breakfast, and go out and run 6-8 miles and not feel tired, shaky, etc., something I could never do when I wasn't LC. Moreover, after I'm done with a long run, I'm not even hungry most of the time, and usually wait a few hours to eat, it's great not having to scarf food down for some supposed window for recovery as well as being really hungry. I know other local keno-adapted long-distance runners who have run 50 milers total totally LC leading up to and including the race, etc.

    1. “I read that measuring one’s blood is more accurate than via a urine sample”

      A point often overlooked is that when one becomes adapted to ketones there will be few, if any, ketones in the urine.

      The reason is simple; you’re using them for fuel!

  110. This weekend I went on a bike ride with my elite-road-racer boyfriend and some of his friends – 30 miles in about 2.5 hours – fasted, refusing their offers of Gu every 45 minutes, and finished strong! Later the boyf and I discussed fat adaptation, and he really can’t believe it. He’s definitely one of those people who gets cranky if he doesn’t eat every few hours. Fat adaptation and intermittent fasting come easily to me, but what about people who are so strongly sugar-adapted?

  111. Mark,

    I really like much of what you promote and enjoyed this article as well. Happily I am a fat burner. My biggest problem with Primal living is your belief in evolution. Because of your belief you give not credence to the Creator’s injunction not to eat the unclean foods such as pork and shellfish. To promote them is a disservice to your readers and followers. May I suggest you look at the scientific basis of how Biblically unclean foods digest and how they impact human health? ~Jon

  112. Some of you mentioned headaches and brain fog symptoms.

    Sounds like low carb dieting to me.

    Since I’ve increased my natural carb intake (of taro, sweet potatoes, normal potatoes, rice and quinoa) my headaches, muscle aches in the chest, brain fog, mood swings, heart racing, high cholesterol, anxiety, low libido and arrhythmia have stopped!

    Having too few carbs can make you excrete minerals, vital to keep your mental health and heart healthy. So if you’re getting same symptoms I did after going on PB, try increasing natural carb intake, increase mineral intake (potassium, magnesium, selenium, copper) and eat more liver to mitigate any loss of vitamins.

    So safe carbs aren’t evil (only wheat & sugar are evil).

  113. Hi there Mark! Great stuff as always my man!

    had to smile that you reached the metabolic flexibility conclusion too.

    Awesome! I am biased as that has been my research focus for the past 6 years and my PhD dissertation topic. I agree with everything you noted here, but the only difference is that not all fat burners are metabolically flexible; but a vast majority are, so it is a fair assumption.

    For those looking at more research, check into metabolic flexibility and the formal name for the theory Mark is talking about is the “Glucostatic theory of appetite control” originally proposed about 50 years ago by Jean Mayer.

    Keep up the great work!
    Rock on
    Mike T Nelson PhD(c)

  114. Bizarre. I eat a whole food, starch based, low fat, high fiber diet and my answers to questions indicate I’m fat adapted. Fasted workout? No problem. Hours between meals? Cravings? Headaches? Nope. Maybe the Maffetone Method did it for me. I’ve been curious about this thanks to Ben Greenfield, but I still don’t get it.

  115. Hi, I know this is an old post, but only just read it!
    I have just read The Art and Science of Low Carb Living, and the performance version. In both books they say that it generally takes less than 50g carbs per day to get into ketosis and optimum fat burning. Also they say that if you have between around 50 to 150g carbs a day you wont be in ketosis, so wont produce ketones to fuel the brain, and wont be taken in enough carbs to get enough glucose for the brain.

    Any thoughts on this?

    Also, Mark makes the comment that you can have a high(er) carb meal regularly. But in the 2 books, and from interviews I’ve seen from the authors, they definitely dont recommend high carb meals, even after exercise.
    Conflicting info?!


  116. Hi Mark, this approach certainly makes sense biochemically, especially for older (going slower) endurance athletes. I’m having pretty good luck with it – see latest blog post https://goo.gl/1pzro.
    Nice site, great info. Thanks for the photo (see blog), which I linked back to your source article.

  117. Hello, I am VERY new to this; I haven’t even started yet; just doing the research, but desperate for my energy levels back, and to lose weight and honestly – just FEEL better. I am really nervous about giving up the “staples” in my diet that I have been accustomed to. How can I get my 3 kids and fiance to be on board with me? Is it difficult/expensive to change all the old habits to become fat-adapting? Side note: I also want to look GREAT in my wedding dress in October!

  118. Based on the signs, I think I am now fat adapted at 5 weeks into the programme. However when it comes to exercise, I can do low level intensity, such as a 3 mile run just fine without carb loading or even in a fasted state. I can even do the same for a bodyweight session in the morning.

    However, when it comes to sprint training with my sprint group and rugby training, I find it difficult to really push. E.g, when I try to sprint my hardest, I cant push my body hard enough to get properly out of breath, cos it just doesnt have the energy to do so. I can jog off fine but high bursts of energy are suffering. I am guessing this is down to low levels of glycogen stores? So, if i needd to up my glycogen stores before or during exercise? I have been trying to eat more carbs the day or two days before training in for m of sweet potatoes or squash and plantain but its not suffice for those intense bursts. Should I have dark chocolate? Honey, more fruit or what? Any advice will be much appreciated because I feel like my body now has the potential to be much more explosive and fast than before but is being limited by not being able to push.

    1. I have the exact same problem, all the other indicators are good but when it comes to doing bursts of exercise like quick sets of jump rope, sprinting up the stairs, or sprints in my bike, my muscles just dont want to do it, they feel too drained!! So what gives?? How is the glycogen supposed to be replenished with less than 100g of carbs per day all being practically veggies? (i’m trying to lose weight, so I’m trying to stay on the “weightloss sweetspot” from Mark’s chart)

  119. I’m fat adaptive, I’ve been an intermittent faster/no grain-eater for the past 22 months. I perform very well in a fasted state on long strenuous hikes and don’t feel all that hungry at the summit (though I do eat and always bring a clean protein and fresh veggies for my meal).

    This is my “problem”: I’ve got two big hikes coming up (one at the end of this month and the next at the end of August and both are beyond anything I’ve ever attempted). The group that I’m hiking with is planning a “spaghetti feed” the night before. I would surely like to stick with what works for me but I’m not sure I can defend my position properly in this crowd where I am clearly the novice hiker. I’ve taken all of their advice for safety, gear, etc but have avoided the carb-loading issue.

    I really like these guys but in all honesty, I believe them to be over-trained and out of shape (each sports a huge belly). They stop often to eat their cookies and granola bars, while I sip on my water. I’m sure their assessment of me isn’t all that flattering either (crazy anorexic or whatever).

    Anyway, I think they’ll be putting pressure on me to carb up and insist it’s for safety. I’d certainly do it if I thought it would help my performance on the hike AT ALL.

    So, could you tell me, would it help my performance??

  120. I have gone six months of cyclical Keto/ carb backloading, and have only recently started to try and get fat adapted. Its only been three days, and I feel no lack of energy in my workouts, and can go more than 12 hours without feeling the need to absolutely devour food. I have never gone longer than 5 days totally keto/low carb, but is it possible that I am already fat adapted?

  121. I do not even understand how I stopped up here, however I thought this publish was once great.

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  122. What, exactly, is the metabolic pathway for dietary fat to be stored as bodyfat, as claimed in this article?

    Quote: “If you’re adapted, your post-prandial fat oxidation will be increased, and less dietary fat will be stored in adipose tissue.”

  123. Can you be fat adapted and still not lose weight? I have had many of the signs of fat adaptation in the past and not lost more than a lb. in months, maybe 1 inch around my waist. And that’s it!

  124. I’m confused. So here you’re talking about being “fat adapted” wherein the body prefers to use fat rather than carb for fuel. Sensible enough. However, other sources will say that to shift the body to a fat burner you must go into ketosis… I’m on a very high fat diet and basically only otherwise eat low to medium starch veggies and meat. I clearly fit into the category of “fat adapted,” yet I’m not so sure about ketosis because I think I eat too many veggies (although my urine often smells since eating this way). Lately I seem to have issues with hypoglycemia (tingling in toe tips) which I haven’t had since inadvertently trying to eat this way two years ago (after which I’d stopped)… If I’m not eating high-glycemic carbs, and eating a lot of fat, shouldn’t my blood-sugar be more stable, assuming all other things are in order?

    Is there any soundness to an argument that if carbs are super low and of only veggies and fat is quite high (~75%), that moderate animal protein could drive insulin to lower blood sugar to dangerous levels as there’s no carb to help lift it back up or balance it? This seems to defy everything, but, well, can’t hurt to ask it…

    1. Hmmm… I think Dave (commenting on November 3, 2012) answered my question. I mainly burn fat. I have to as it’s most of my diet. However, the seeming hypoglycemia isn’t a blood-sugar issue so much as it comes about because I’m not quite in ketosis nor eating adequate carbs for sufficient brain fuel… Thanks Dave.

  125. Hi I’ve been a fan since Feb 2014. Since going grain free and mostly Paleo, I have always wondered why my energy in the gym has soared ( been going since 1979 steady ), now reading your article about how do you know if you are fat adapted i think i understand.
    I will no longer say to my friends..: ” I wonder where all this energy comes from ?”
    Truly remarkable.
    You, Mark were the first step in changing my life for the better. Thank you. Mario.
    P.S. I am 68+ years young.

  126. I’m wondering what you’d advise for me, as I have Fibromyalgia chronic pain/inflammation & fatigue. I’m not able to exercise & generally need to rest/recuperate from the little activity I currently do.
    I’d dearly love to increase my energy reserves, especially for general endurance. I’m also very interested in lowering my pain levels along with my body fat percentage.
    Have you worked with anyone else in similar circumstances?

  127. Kerri. I have Fibromyalgia also and have found that routine and consistency is paramount to boosting healthfulness and energy levels.
    I eat a low carb diet and keep my protein up. I use the my fitness pal app to try to keep everything the same every day. I use gentle exercise. Always drink 1800ml of water. Always have two cups of coffee and always go to sleep at 10 and wake up at 7.
    I pay close attention to my body temperature and work hard to keep it consistent even if that means putting on/taking off my jacket 15 times a day.
    I also have a consistent energy intake. I don’t eat gluten and I avoid msg like the plague.
    By being ridiculously consistent I have alleviated my symptoms considerably and my flares are now only happening a few times a year for a week or so and then I feel better.
    I do really believe that gentle exercise every single day helps and exactly 9 hours sleep.
    Good luck

  128. Thank you for this article — it explains so much. Regarding ketosis, my body used to go into it after skipping even one meal. The transition to ketosis was rough, and it was an uncomfortable state to be in. After becoming more fat adapted, my body seems to easily adjust the fuel mix on the fly. (Hooray no headaches, no funny breath.) Also I lost weight after becoming fat adapted; I don’t think the ketosis state is necessary for weight loss, as many believe.

  129. So, if I understand this correctly, I can become fat adapted, and become healthier, by increasing fat, but I don’t have to give up fruit and potatoes, as long as I don’t indulge in junk carbs.

    Is that correct?

    Because, I was thinking about Keto, but this sounds way better.
    I can do without junk carbs. Not so sure I could give up peas, blueberries and sweet potatoes.

  130. I’m on a bunch of meds: Prozac, Adderall, birth control. I’m also currently on an antibiotic for sinus and ear infections. I can’t get my blood glucose to continually be under 80. I check my ketones via blood but not very often as the strips are expensive. I’m usually between 1.2-1.5 on ketone meter. (This is all fasted, BTW.). I /am/ under constant stress due to a rocky marriage. I keep adjusting my macros according to a couple different people online. Now I’ve been bouncing around 50- 53 lbs lost for the past month. I’m 42, female, 264 as of this morning, 5’5″, and currently very lightly active. I’m not sure what type of exercise to do as I’m hearing different things. I want to be healed, be healthy, get rid of this excess body fat, and tone my body. I’m afraid to eat too much protein because of Gluconeogenesis and afraid to eat to little because of my body using muscle for energy.

  131. Should one even consider blood glucose or ketone levels for “fat adaption”? I have all the tell-tale signs of fat adaption, but my blood glucose and ketone levels are all over the place.

  132. You I am interested in the last part of the article which states that glucose is scarce in a ketogenic state. I thought that the whole point is that the liver manufactures necessary glucose for the brain through gluconeogenesis? Or am I mistaken?

  133. I really love the concise explanation of fat-adaption and the contrast between ketogenic diets and the primal lifestyle. I linked to this page in my article “Wake Up and Smell the Fat Burning”. After reading this I realized I am fat adapted! Now I can continue melting fat like butter. (Mmmm butter!)

  134. I’ve been doing fantastic with primal eating this summer. I find it quite easy to stay on track. I get hungry about 9 o’clock in the morning, two hours after I wake up. I don’t crave carbs at all. But I do feel like I really need to eat in order to concentrate. Does that mean I’m not a fat adapted? If so, why am I not fat adapted?

  135. I’m not very clear as to how much 80% fat a day means – practically speaking.
    I’ve pretty much replaced most of my carbs with fat and have always eaten lots of veg and some good protein (mainly oily fish, chicken, some duck – no dairy – can tolerate the stuff) and I actually feel that im putting on weight.
    I don’t like counting grams of food or counting calories – is there a rule of thumbs for proportions in a meal?
    I mix my exercise up from 40-45 min runs – twice a week – a hiit session 30 min once or twice a week – lots of stretching and sometimes just the stretching 2-3 times a week.
    I also do meditation daily and try and reduce stress all the time as I totally get the cortisol-weight connection.
    My aim is to lose about 8-10 kgs.
    I’m 67kgs now – would like to go under 50kgs where i feel my best.

  136. I’m just now learning about this concept of being fat adapted. I have struggled with low blood sugar all my life, even as a little child. I get disoriented, light headed, and confused. Is it possible for me to be fat adapted? Are there some people that shouldn’t do this for medical reasons?

  137. I am a 64 year old female and have been on a modified Ketogenic diet for more than a year and a half and have lost 100lbs. My macros are 120P 70F 20C. I supplement my electrolytes daily. This way of eating has changed my life in miraculous ways. I have one persistent issue, thirst. I cannot seem to quench it. My mouth is so dry I’m needing to chew gum all day and I wake up several times through the night needing to drink. My mouth gets so dry it’s uncomfortable. I’ve tried several things like upping my sodium, reducing my sodium, adding potassium 400mg qd. I’ve used Biotine and that hasn’t helped. I have no other symptoms of dehydration, my urine is pale yellow. I do urinate a lot as I am drinking about 120-150ml of water a day. Any thoughts?

  138. Hi Mark! I found all your posts extremely interesting and I am on my way to become fat adapted.
    I was wondering if when you have a low HRV – the aerobic level varies.
    I should run quite faster to get to the 144bpm (I am 34) and I found completely contradictory that in the aerobic level I cannot maintain a conversation or breath if I have really hard time to get my HRV to 144 bpm.
    Or is it that I don’t understand yet the HRV measurement?

  139. Great post Mark! Being fat-adapted would have a really big effect on getting healthier and reducing body fat percentage. Amazing advice. Thanks a lot for sharing 🙂

  140. Take a look at Lumen.me, this is a new device (I bought one this year at CES) which measures the CO2 ratio and indicates your fuel or fuel mix. It’s purpose is to get your metabolism adapted as in this article. Works well so far.

  141. When people ask how I lost weight I tell them I’m changing from being a “sugar burner to a fat burner”, and then they say, Yeah that makes sense. But if I say Paleo, then I get all kinds of answers. Great article, we are seeing so many people today with all kinds of sugar problems and a vast number of Americans on the verge of diabetes simply because of eating habits and how easy those habits can change.

      1. Editörlerimizin ara?t?rarak haz?rlam?? oldu?u Bitkiler alemi, Gezi rehberi gibi birçok kategoride ki yaz?lar?n? sitemizden okuyarak bilgi edinebilirsiniz.

        1. Take a look at Lumen.me, this is a new device (I bought one this year at CES) which measures the CO2 ratio and indicates your fuel or fuel mix. It’s purpose is to get your metabolism adapted as in this article. Works well so far.

  142. Aren’t ketones produced as a by product of fat oxidation? So if you are a fat burner, you will produce ketones. The better you are at burning fat, the more ketones you produce and, conversely, the less stored fat you burn,

  143. Overall, I’m pleased I took this next step in my life. I couldn’t believe how an already fit and nimble person had advanced to a new and distinct level.

  144. Thanks for sharing such valuable content. I really like the tips that you provide for fitness and health. and I have been following your blog for quite some time now.