Dear Mark: Should I Increase Carb Intake for Weight Loss?
Sometimes, weight loss slows. Sometimes, what worked amazingly well before, stops working quite the same. Although this can be scary, frustrating, annoying, or all of the above when progress slows, stops, or requires new input to continue like it was is ultimately okay, because we are an adaptive species. We can change things up, shift stuff around. Physiological processes (among which weight loss and metabolism can certainly be counted) are never linear – that’s partly what makes all this stuff so endlessly engaging.
Today, I revisit a strategy for overcoming these lulls in weight loss induced by low carb: carb (re)feeds. They seem counterintuitive, sort of, especially if you’ve had success restricting carbs, but hold you opinions until you read on. I think you’ll find it enlightening.
Dear Mark: Your blog is a treasure trove of valuable information. Thank you for keeping this resource available to us!
This is a question that I think many of your readers would appreciate seeing addressed in a post. [Background: I've been studying (and trying, periodically) various low carb regimens for many years, with varying degrees of success. I'm looking to metabolize off about 30-40 pounds of excess fat, build lean muscle and optimize my health and fitness.]
My question is, what do you think of the increasingly common recommendation (from various diet and fitness gurus) to “spike” calories and carbs one day per week, in order to keep the body from down-regulating certain mechanisms too much due to continued low carbohydrate intake? The theory is that a once-per-week carb/calorie spike gives the metabolism a boost, and keeps weight loss going at a better rate than simply sticking to the low carb regimen seven days per week.
I’m wondering if this recommendation for one “free day” per week is helpful or harmful to the objective of significantly reducing excess body fat over a period of a few months, and staying lean for life. I don’t mean a “be a fool and eat garbage” day, but an honest “spike the carbs and calories with healthy foods” day. What do you think: Would this be a weight loss booster overall, or just a setback on the road to burning excess fat and getting to an optimally lean body composition?
Thanks, Mark! I (and I’m sure your other readers) will value your opinion on this.
Dee
I’m happy to help. Thanks for the kind words.
Short answer: Yes, I think there is something to the lowish-carber’s occasional carb and calorie fest. Its relevance to a given individual depends on that person’s metabolic situation, of course, but I wouldn’t dismiss it out of hand. Check out my previous posts on leptin and carb refeeds and weight loss to get an idea.
Longer answer: If you’re eating low-carb and low-calorie (which low-carb tends to promote on account of its inherent satiety) and the weight has stopped dropping, you may be low in leptin. Why does leptin matter, and what do calories and carbs have to do with it?
Leptin is a hormone that fulfills two primary roles, as far as metabolism and weight loss go – it increases (or lowers) energy expenditure, depending on perceived energy availability, and it inhibits appetite. Both actions actually happen in the brain, but it’s leptin that gives the brain the message. If perceived energy availability is “low,” energy expenditure drops and appetite increases. If perceived energy availability is “high,” energy expenditure increases and appetite drops. That’s a quick and dirty (and incomplete) overview, but it serves our purposes for today’s discussion.
How does the body “perceive” energy availability?
Body fat is, quite literally, stored energy. It’s also an endocrine organ that secretes leptin, the amount of which in circulation is directly proportional to the amount of adipose tissue on your body. So, the leaner you get, the less body fat (and less stored energy) you have available to drive leptin secretion. Even if you’re not as lean as you’d prefer to be, your lower body fat levels are low enough that the brain isn’t getting the “high energy availability” message from leptin.
Insulin is another indicator of energy availability. Sure enough, insulin increases leptin secretion in fat cells. As far as the body’s concerned, if insulin is present in significant amounts, food has just been eaten, which means food is probably available in the environment. If food is readily available, the body doesn’t need to cram as much food in, nor does it have to conserve energy. It can do things that aren’t essential to immediate survival, like play a game, have sex, go explore, or work out, because there’s plenty of energy available. Leptin goes up, reducing appetite and increasing expenditure. Problems arise with leptin resistance, of course, when your insulin is constantly elevated, but I’ll get to that later.
Carbohydrate content of the diet, perhaps independently of the increase in insulin, also affects leptin levels. Protein also increases leptin, and fat seems not to, but carbohydrates have the largest effect.
Overall calorie content of the diet is an indicator of energy availability. Studies show that calorie restriction causes the body to lower serum leptin levels in order to protect against further weight loss, and that supplementary leptin kickstarts weight loss all over again.
Ultimately, then, leptin is how the body senses both incoming and stored energy. It goes up in response to food eaten, as well as food stored. And since day-to-day survival of an organism is largely about energy availability, the presence or absence of leptin can make life pretty awesome or pretty awful. This doesn’t just impact weight loss or gain; it impacts your enjoyment of life. Low leptin? You might not feel like taking that walk with your friend. You probably won’t want to work out. Your libido might suffer. You might not feel like doing much of anything except sit around.
Can you see why lagging leptin might be an issue in stalled weight loss during a diet? You’re dropping calories (an indicator of reduced energy availability), dropping body fat (an indicator of reduced energy availability), and, especially if you’re low-carb, you’re dropping insulin and carbs (an indicator of reduced energy availability). All these things tell the body to make less leptin, and less leptin means higher appetite (so you eat more) and lower energy expenditure (so you burn less fat and don’t feel like doing much of anything).
How Should You Do It?
As I mentioned in the refeed post, keep the fat content of your meals down when doing a carb feed – about 50 grams for the day. Why? For one, fat doesn’t have as much an effect on leptin as carbs or protein do, and two, since triglycerides have been shown to prevent leptin from crossing the blood-brain barrier (into the brain where leptin does its work), the increased postprandial triglycerides (which are a normal, temporary, physiological consequence of eating fat and different from elevated fasting triglycerides) may reduce the effectiveness of leptin.
The greater you normally restrict carbs, the more you eat on your refeed. If you’re hanging out in the 100-150 gram range, you probably won’t need much – if any – of a boost in carbs. If you’re below 100 grams, I’d do 250 grams or so. If very low carb (below 50 grams), shoot for 300-350.
Do your refeed on a training day. Lift/sprint/run/hike/play big and, then, eat big. Your insulin sensitivity and leptin sensitivity will be high, your glycogen will be depleted, and you will basically be set up to store/burn the carbs and muscle energy rather than store it as fat. Leptin will increase regardless if you train or not, but doing it on a training day will mitigate any metabolic fallout.
Don’t use this as an excuse for stuffing your face with garbage. I mean, I suppose you could truly turn it into a cheat day and eat a couple pizzas, a gallon of ice cream, and a platter of crispy oxidized soybean oil-infused whatevers, but you’ll have better results with potatoes and yams (or even rice) and animals.
Who Shouldn’t Do It?
A big carb feeding isn’t right for everyone. I would say that for the severely overweight-to-obese, you should not be messing around with carb feeds. It’s not that they’ll wreak irreparable amounts of damage on your metabolism or anything; they just won’t be very helpful. See, the obese tend to be insulin-resistant (PDF). They have tons of leptin in circulation, far more than lean individuals, but it cannot do its intended job. Instead of telling the muscles to burn more fat for energy and telling the brain to quell the appetite, leptin’s message in the obese is muffled, stifled, hamstrung. It can’t get through. Lack of leptin is not the problem, as the considerable amounts of adipose tissue are doing a fine enough job manufacturing the stuff. Sensitivity to leptin in the brain and periphery is the problem. Thus, adding more leptin to the bunch via dietary manipulation won’t help, and it may even compound the problem. Improving leptin sensitivity is the real issue here, and a lowish-carb Primal eating and general lifestyle plan (with adequate sleep, smart training, and plenty of stress mitigation) is the best way to do that.
Who Should Do It?
Leptin is most effective in the lean, moderately lean, and somewhat chubby (yes, those are absolutely technical terms). Men with six-packs, four-packs, two-packs, and men and women with a light layer of subcutaneous blubber covering everything up tend (a la those hunter-gatherers who aren’t exactly “ripped,” but definitely not unhealthy) to be essentially leptin-sensitive. In these individuals, leptin acutely boosts skeletal muscle fatty acid oxidation.
Those with “stubborn” body fat, those on an extended stall, or the otherwise lean who can’t quite seem to get the last dozen pounds to disappear are prime candidates for a big refeed. They’re not so overweight that leptin resistance is likely, so they’ll benefit from a general increase in leptin. They’re fairly lean, so circulating leptin is lower.
Anyone who’s “feeling off” from low-carb Primal, despite their best efforts. Say you’ve given the low-carb flu a chance to pass over, you’ve addressed your sleep and stress, you’re not trying to train like a pro athlete, and you’re still feeling run down and unable to lose weight? Throw in a big carb feed.
What about you guys? Have you experimented with carb refeeding, and if so, how did it impact your weight loss efforts?
Thanks for reading!
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Posted By: Mark Sisson
This is gold, Mark!
Try stir-frying your yams/sweet potatoes with sweet onions and coconut oil/butter. Pinch of salt and pepper. It’a a 3-generation favorite for our family we serve any time of day.
Any suggestions for refeed foods? I’ve been doing it all wrong ;( carb + fat.
Can’t think of strictly carb, low fat foods that actually taste good.
Any ideas?
Fruit, rice, squash, yams, potatoes, more fruit
So glad to see this post. I’ve lost 15 pounds in 2 months of very strict (90/10, and that 10% is always low carb, but not organic) Primal eating, never more than 70g of carbs, but most days less than 50g. I got stuck for about 2 weeks at 10 pounds down. What broke that plateau was a night out with friends that included 2 whole sushi rolls with rice (I thought, screw it! I know Mark said rice was okay somewhere on MDA. And I’m not going to dip in the soy sauce, so there!) and a couple of glasses of red wine to boot. I was so afraid to get on the scale the next morning but I was down a little! And the scale started going back down to the additional 5 I’ve currently lost. Vacation is in 39 days and I’d love to get rid of 7 more pounds before then. I would have thought this to be near impossible as I am getting very close to ideal weight, but maybe with the refeed it will work! Akina Sushi, I’m coming for some Sin City Rolls!
One thing that I noticed was the lack of using fruit as the re-feed source. Was this an oversight? I guess this is due to the fructose. I’ve read (probably here) that fructose goes directly to the liver and is digested differently than other carbs. Maybe this process creates a different leptin response from what is laid out in this post as compared to yams, rice, etc.(a.k.a. safe starches)?
when I go carboverboard for any given off the tree and onto the ground reason…I pound Macadamia and Brazil nuts over the course of the day…every once in a while…never even once a week. Those are my “carbs” of choice…you would have to force a sweet potato into me..EWWWWWwwww!
LOLOLOL
Interestingly, Tim Ferriss also recommends this once-per-week carb “re-feed” in his 4 Hr Body book.
I find lots of synergy between the Primal/Paleo lifestyle – Pareto Principle i.e., 80/20 rule), basically primal eating, heavy weight-bearing exercise, and de-stressing by turning off as much of the modern world as you possibly can – and Tim F’s books (4 hr workweek/body). I know Mark has recommended his books before; I second that, especially for the workable advice on how to decouple from modern stress.
The re-feed is also a great example of what generally works well for me too, so long as I’m still basically eating clean while doing it and not using as an excuse to eat garbage
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Great post!
You don’t have to tell this crowd twice to have a cheat meal Mark!
I love the explanation of how leptin works. Really well said.
This topic has been on my mind a lot lately and I just listened to John Keifer on the Upgraded Self Radio podcast. Def recommend people listen to that if they want to learn more.
And the light bulb over my head goes ON! I don’t know how many times I have dreaded the scale because I know I’ve overdone the carbs (but never grains–bad bad bad for me), only to find that I have dropped a couple of pounds and that the loss keeps up for a few weeks. Time for a refeed!
Very informative article. It seems that an occasional “refeed” does help to speed up weight loss. Just as long as it is indeed occasional & doesn’t become the norm.
Thank you so much for clearly stating that people who are severely overweight and insulin resistant should not load up on hundreds of grams of carbs. That’s a very important point.
As someone who is highly insulin resistant and obese, I can get away with the occasional cheat–I’m talking every few months or so, not a regular cheat day. And probably only 50 or 60 more carbs than usual, if that.
I will usually see a nice loss after doing so. But adding in 250 or more carbs at once would be very harmful, I think. I doubt I could bring myself to do it.
I really appreciate your distinguishing between young, fit, healthy primal eaters and those of us with severe insulin resistance. Our metabolisms are VERY different!!! That’s great–I hope you will carry it over to other posts as well.
Last time I added in some extra carb (via yams), my blood sugar went higher than acceptable.
I had some initial success with alternate day partial fasting, but I’ve stalled a bit (and I think it might be from too much carb on “up” days). I think I will experiment with fat & protein percentages to see what effects that has.
This is a timely subject for me personally, as I just discovered a LOT of info (from paleo women website) about women with thyroid issues eating too low carb/too strict paleo – which is exactly what I have been struggling with! I know this article is a bit different, but in some ways relevant, and I would love to learn more/read more about women specific issues with eating more carbs, especially with low thyroid concerns………
Same here. I’m diabetic (no meds) as well, so it’s sort of a tightrope walk. I’ll have to go by the glucometer.
Same here, I had a lot of the symptoms she described such as feeling like I had been hit over the kidneys and sore feet in the AM. Upping safe carbs every few days (+ a little dark choc) has gotten rid of these symptoms and I’ve strted losing weight again. I get them back if I don’t eat enough carb. I’m only talking about upping from say 30g per day to 80g though.
Thank you so much for posting this info. I am 48, finally losing via Ideal Protein diet, but have to keep my calories VERY low and so strict to lose. So far I’m down 25 lbs. in 3 months.
Are you referring to the site paleoforwomen.com?
The thyroid “issue” is normal. Maybe what the experts consider “normal” is actually “high” and the numbers on a VLC diet are “normal”. It’s physiological, not pathological. In fact, there’s a few articles on it over at Hyperlipid. It comes not from VLC but from not enough calories (And if you are getting enough fat while VLC how can the body think it’s “starving”?)When you are VLC you must get take in calories than you would normally. I’ve got a dysfunctional insulin response that can’t be fixed thanks to the genetic issues. The damage has been done. I have increased carbs even with the “safe” ones. They don’t send my blood sugar skyrocketing but my fasting sugars start going up and the blood sugar “lows” come back. It sucks.
take in MORE calories than you would otherwise
I guess I blew my carb refeed today since I ate my potato with a third a stick of butter.
Great article, I for one am for cycling, it works for me. Depending on the level of my activity I will usually have a re-feed as often as 1 in 5 days. The reverse is true too if you are trying to gain weight by bringing your calories/cabs back to normal will also assist maintaining a stready gain.
Some good tips still not convinced about low carb diet tho.
But I will look further into your site for more insights before I make up my mind.
Best way to be convinced is to try it. 30 days, nothing to lose but fat.
Low-carb is a bit of a misnomer — more like this is a high-fat diet that is grain & refined sugar free. Everyone settles to their own comfortable starch/sugar intake.
Great post Mark! I have been eating Paleo almost one year now and I’m leaner than ever and no matter how much I eat it stays very steady.
when I started, however, I initially lost some weight but stalled and actually gained weight. I then gave up eating my big daily dose of nuts (nut butters and raw, shelled nuts)and way too many fruits, and the weight melted off. I eat 85% dark chocolate every day, but at least I’m not dipping it into jars of almond butter anymore!
Typically I start my day with protein and fat (eggs, bacon, avocado) and keep the carbs (sweet potatoes) for lunch or dinner, usually post workout. I don’t seem to need any “cheat days” and I don’t like the concept of working that in to a weekly schedule. I just use my cheats for days when I’m in a bad spot.
Any specific frequency? It seems most people do a “once a week” thing. However, our modern “week” seems to have little meaning to our evolutionary physiology, does it? I’m in Nutritional Ketosis (<25g/day) and have wanted to try this, but Dr. Phinney said in an interview once it may take 3-4 days to get back into Ketosis after a "cheat" day. That seems like doing a carb-refeed would leave about 2 days per week in Ketosis which seems pointless.
Would once a month work? Once every 3 weeks? Is the once a week idea based on any science?
Thanks.
you could run sprints the two mornings after the refeed – hiit I think mimics the effects of ketosis, while also helping deplete glycogen, helping you get back into ketosis faster. Typically, I refeed and go out of ketosis on Saturday, and am back in ketosis by Tuesday. I look lean the morning after the carbs. For what it’s worth
Iv been doing some research and from what I understand 3 days low carb and 1 day refeed works well.. But what ever works for u really, everyone is different
As a Creationist, I believe there is a physiological (not to mention celestial) reason for our “modern” week. A very interesting question about which I will not be dogmatic, but I will say that when Napoleon tried to make the week metric by going to 10 days instead of 7, it didn’t work out very well. Sketchy and anecdotal for sure, but interesting nonetheless.
My cheat is always ICECREAM! It takes a day or two to start to drop more weight. But It always does.
what about doing a week or two of a carb refeed?
I have been stuck at the same weight for a over a month now. I starting eating ‘clean’ two weeks ago, and take in ~60-70g carbs. I’m currently 5’9″ 158.8 and would like to be 150lbs. I have not lost anything, and when I do one day refeed I gain 1-2lbs and then lose the same amt. I usually eat ~1100-1300 calories.
I read some places that I should increase my calories to 1600-1900 and 150-200g carbs (healthy carbs).. Any suggestions?? Im just worries I will do this and gain crazy amts of weight. please help!
It sounds to me like you need to eat more calories. Carbs you can try different amounts of, but if you starve yourself too much for too long your metabolism will go down eventually. I don’t know your activity, but at your height and weight I would think you should definitely increase your calories even if you aren’t that active. But the nice thing about paleo/primal is that you shouldn’t have to track your calories. Just eat real food and listen to your bodies signals of fullness and hunger.
this has been your greatest post to date! thanks a ton and keep up the great work! it is very much so appreciated.
I lost 40-odd pounds on Joel Marion’s “Cheat to Lose” diet (and Xtreme something.) And now I’m doing Geoff Neupert’s Kettlebell Burn Extreme, which in addition to cheat days adds IF and cold showers. I want to say that I’m a firm believer in “be a fool and eat garbage.” Mr. Marion, to be fair, argues against this. But, I lost fat at a pretty good clip and I never had to wait more than six days between seeing food and eating it. It’s fantastic for adherence.
Interesting, I know this topic has come up before and someone mentioned the Perfect Health Diet (they advocate Paleo but ‘allow” safe starches – white rice, potatoes (white and sweet) and rice noodles. When I do strict paleo I feel great at first, but then a few weeks later my mood swings and irritability are out of control. Since introducing their method I feel so much relief. Obese people seem to lose weight using it too, as long as they keep their fat intake low while eating the starches.
Awesome post! Like mentioned in the post that “Physiological processes (among which weight loss and metabolism can certainly be counted) are never linear.”
I agree this statement 100%. Speaking from experience, occasional carb refeed do help, but there have been times where the occasional became often. Discipline is very important.
Perfect timing for this post Mark!! I have been doing a bit of research lately about refeeds. I am following the simply shredded- The Deadline Diet, which follows paleo guidelines and refeeds on every fourth day. I have always been slim and healthy but struggling to lose those last few stubborn pounds! I’m sure this will give me the kick start my metabolism needs for sure! Let you know how it goes!
For a practical ( and in my opinion, awesome) way to implement this, check out http://www.leangains.com , which Mark has himself linked to in the past as an example of intermittent fasting. I’ve been doing this for a month now, and have been setting PRs in every lift, every week.
I think carb refeeds/ cycling/ whatever you want to call it are essential for performance, but if you ask me, you should not be dong them unless you are following a very basic primal tenet, namely… LIFT HEAVY ( AND I MEAN HEAVY) THINGS!!!
Great info. I’m wrapping up day 19 of a planned 21 day fast, and the last week my energy level has been about as low as ever – I could barely walk upstairs. So this may have been a leptin response. I feel great today with nearly normal energy level, so looks like I’ll wrap up the fast on a high note. I’ll keep the carb refeeding in mind for post fast. Thanks for the post Mark!
Seriously? 21 days straight or a Ramadan type quasi-fast? You haven’t put calories in your mouth in 19 days? I would love to hear how that went for you.
Joshua – sorry I missed your response earlier. This wasn’t Ramadan style – I had zero caloric intake for 21 full days – water, coffee and teas were the only things I ingested. You can follow the progression at the MDA Forum/Journals/David’s Fasting Journal.
I love that carb refeeds are really a thing. When I first lost weight on Atkins (I was more Paleo than most, though, since I hate unnatural food/meal replacements) I noticed that if my weight loss stalled, I could get things going again by a calorie and carb refeed, usually with rice or potatoes. I even joked with someone I was helping with weight loss by saying “If weight loss stops and energy is low, sometimes you just need to eat a chocolate cake and drink a 12 pack of beer.” Hyperbole, yes, but based on experience.
I would like to point out the Nature article on rice (and possibly potatoes/wheat, and by possibly I mean quite likely) interfering with gene expression, that of the super-important LDL receptor. Piqued your interest? Andrew at Evolvify has a beautiful presentation/discussion of the info (with witty advice as well). Basically, treat your refeeds with suspicion and use sparingly to elicit beneficial leptin changes and don’t go overboard b/c of leptin/insulin AND miRNAs. Enough to make one’s head spin, yeah? In defense of miRNAs, see the comments of “Matthew” in the discussion (maybe mammalian miRNAs like in cow milk, similar to human breast milk, turn out to be a-ok?)
http://evolvify.com/rice-wheat-potatoes-interfere-with-gene-expression/
The answer to your question is YES! I use re-feeds quite a lot in my clinical private practice (I am a Registered Dietitian). I myself am paleo and I have quite a few clients that follow a primal/paleo lifestyle and the ones that lift heavy and train often eventually get to a point of stalled fat loss and even in some cases catabolism of lean body mass.
At that point we institute a re-feed day, usually about twice a week, depending on the training schedule of the individual (there’s definitely no one-size fits all formula).
I myself train twice daily about 4 days a week, with strength and then conditioning work, and two other days of one or the other; and I find that about every 3-4 days, I need to boost my carbs from about 150 to around 200-225.
Particularly if you are trying to put on lean body mass in significant amounts, you NEED those carb re-feed days, otherwise you just can’t build the quantity of muscle that a strength athlete will need to continue that training volume. This also becomes true for your ‘average joes’ that undergo some significant weight loss, only to stop losing around that last 10-15 lbs. Increasing their training volume, as well as cycling their carbohydrate intake seems to work beautifully for about 90% of the clients I work with.
Great article Mark! Nice to seem some objective thoughts on the concept of eating more carbs every once in a while (within reason of course!).
Hrm..does this apply to alcohol? I bizarrely craved alcohol the other week…I put a major dent in a bottle of pura caña rum over the course of a cleaning day. It smelled and tasted sweet and delicious like I could chug it — but have had no taste for it since and even today tried tasting it and put it down. While metabolizing it, I felt very warm, social and active.