Dear Mark: Saturated Fat Jet Lag, Collagenous Amino Acids, and Different Cutting Diets

Sat Fat Jet Lag FinalFor today’s edition of Dear Mark, I’m answering three questions. The first concerns a recent study seeming to show that saturated fat disrupts our circadian rhythms, especially saturated fat at the wrong time of day. Should we—yet again—trade butter for soybean oil? Second, how necessary are the amino acids found in collagen? Aren’t they found all over the place, not just in collagen? And finally, I answer a couple questions about cutting diets (those traditionally low-fat, low-carb, high-protein diets) and if they can be adapted to a primal way of eating.

Let’s go:

Dear Mark,

What’s your take on this study:

It says saturated fats disrupt the circadian rhythm and lead to metabolic dysfunction unless you eat them in the morning. Thoughts?

This paper is another in a long line that exposes cells in petri dishes to isolated palmitic acid and extrapolates the results out to whole foods diets. And yes, it’s really easy to find lots of corroborating evidence for the evils of isolated palmitic acid, particularly isolated palmitic acid petri dish bathing:

  • Palmitic acid lowers expression of the LDL receptor gene. Less LDL receptor activity means LDL hangs around longer in the blood, has more time to become oxidized and cause trouble.
  • Isolated palmitic acid is toxic to isolated skeletal muscle cells. It impairs glucose uptake and increases insulin resistance. It’s generally good for muscles to accept glucose and respond to insulin.
  • Palmitic acid induces an inflammatory state and disrupts insulin signaling, two harbingers of diabetes. Nobody wants diabetes.
  • Palmitic acid damages heart muscle cells. The heart’s quite important.

It’s all scary stuff. It’s enough to make you swear off butter and become a fervent defender of orangutan habitats in palm oil-production zones. Except:

In other words, palmitic acid in the wild is never alone. It always comes with these mitigating fatty acids, like oleic or arachidonic acid.

Now, the recent study you reference may be different. Maybe the circadian-disrupting effect of palmitic acid isn’t offset by oleic acid or any other whole food nutrients. It’s possible. But I doubt it, given the track record.

These petri dish studies aren’t useless, of course. They do provide mechanisms that occur in the real world. The petri dish isolates everything: the object (the cell line), the environment (the dish), the actor (the palmitic acid), the effect. It’s all singular, refined, granulated. But that’s just the one mechanism, unaltered and unbound. Everything changes when you introduce other variables, like, I don’t know, other fatty acids.

Don’t throw this one out. Integrate it. Maybe it’d be cool to try eating most of your fat earlier in the day. Maybe you’ll sleep better. Maybe eating some sardines (a good source of DHA, the PUFA the scientists discovered did not impair circadian rhythm) alongside your saturated fat is a good idea. Maybe don’t use that Just don’t forget that scientists use these specific nutrients in isolated unrealistic conditions to study an isolated mechanism. They’re not saying you can’t eat butter anymore.

And if they are, they’re wrong.

I have taught a little bio cheese and physiology and so I would like to understand something regarding eating collagen.

When we eat collagen, we would normally break it down into its component amino acids and then absorb those amino acids. Then we would process it and synthesize new collagen with those amino acids. But these amino acids are found in many other proteins – so why do we need to eat collagen?

this doesn’t make sense to me.

First of all, I would love to learn about bio cheese. Sounds delicious.

Second, it’s true that glycine can be found in other protein sources. But collagen is concentrated in only some of them. It’s a supplement that replaces a missing yet vital element of the traditional human diet: skin, bones, and connective tissue. If you look at the top sources of glycine, they’re mostly all odd bits of the animal. Lungs, hocks, skin, ears, and other assorted and delicious oddities. And at the very top is isolated gelatin, which is entirely collagen. You can get glycine from other sources like muscle meat, but it’s not enough and you’ll also be getting a massive dose of methionine, the amino acid that must be balanced with adequate amounts of glycine.

Hi there,

Very interesting website. I am very interested in your opinion on the following question:

Is it healthier/better to do a low calorie, low fat ketosis diet (eg. popular diets such as the max 500 calorie lean protein, no/low fat, with only a small amount of veggie/fruit), or a more moderate primal diet where you are not necessarily in ketosis?

Does the insulin resistance side effect of ketosis diets make those diets less preferable to a more moderate primal diet which is not dependent on ketosis? IE, is it healthier/wiser to do ‘sweet spot’ weight loss, (as much as the alternative fast weight loss that comes from the ketosis phase might be attractive to some people….)

Thanks so much!

Those extreme low-fat, low-carb, high-protein diets, also known as protein-sparing modified fasts (PSMF), certainly can work. In the literature, longer term PSMFs are always done under medical supervision with plenty of biomarker monitoring and supplementation. Out of the clinic, they are good short term hacks if done properly. If you’re on your own, the safest way is to alternate them with days of normal eating. Something like 1-2 days on a normal diet followed by a day of PSMF. Repeat. More seasoned dieters can do them for a few days to a week to cut weight quickly, particularly as you approach your goal weight but still have stubborn body fat to shed. Just be careful.

I prefer the standard Primal eating plan, of course. It allows for greater diversity of food and a wider array of nutrients. It’s more sustainable, pleasurable, and, well, normal. But you can always throw in a round or two of PSMF (even a Primal PSMF) for variety and quicker weight loss.

As for insulin resistance from ketosis or very low-carb dieting, it depends.

Insulin resistance is okay as long as you’re not eating carbs and generating lots of insulin. This is physiological insulin resistance, where what little glucose you have is spared for the brain and the rest of your tissues rely on fat and ketones for energy. It’s actually a feature, not a bug.

If you’re wolfing down carbs willy nilly whenever the mood strikes you, you’re not going to be in ketosis but, because of the high-fat intakes, you will be insulin resistant. That’s a recipe for metabolic dysfunction and weight gain. You have to be strategic about combining carbs and ketosis. Eat them around intense workouts that burn a lot of glycogen. If you have glycogen stores to fill, or “glycogen debt,” any carbs you eat will go toward restoring those glycogen stores and won’t interfere with ketone production. It’s pretty cool.

Hope that helps!

That’s it for today, everyone. Be sure to offer your own experience or expertise down below if you have something that might help today’s questioners. Thanks!

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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29 thoughts on “Dear Mark: Saturated Fat Jet Lag, Collagenous Amino Acids, and Different Cutting Diets”

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  1. Had to laugh because I’m eating sardines (mentioned in the first question) as I’m reading this, and had collagen (second question) blended into my coffee this morning. Two of my favorite foods for good skin!

    1. Interesting, Elizabeth, because I, too, just finished a can of sardines. I love sardines and eat them 2 or 3 times a week for all the health benefits.

  2. I consume fats of all kinds throughout the day, and if it weren’t for this AND the magnesium I take in the evenings, I wouldn’t HAVE a circadian rhythm…just like in the bad old days.

  3. Interesting! I haven’t really looked into the idea of a protein-sparing modified fasts, but I’ve certainly done versions of them unknowingly. I always thought juice cleanses were bunk because they left out any substantial protein intake, which let me to think our bodies would start catabolizing our own muscle tissues at some point. So when I’ve done semi-restrictive periods of eating, I always make sure include a good chunk of protein.

  4. Hm. I’ll keep this in mind. But like you said, Mark, fatty acids usually don’t come packaged alone. I don’t think I’ve experience the “jet lag” effect of saturated fats in the evening (and maybe that’s why). I’m not sweating it. Great post!

  5. It’s funny how some studies and researchers still attempt to demonize saturated fat. With regards to saturated fat, to my knowledge, this is the only real world study every conducted, the Tokelau study:

    Now it’s not even a study but more of an observation as to what happened over a number of years from a population that went from eating 70% saturated fats, to a western style diet. Then went back to their 70% saturated fat diet again, when western food became available.

    That is the only study that ever should be quoted when talking about saturated fat, because I said, to my knowledge, it’s the only real world study/observation that occurred over a number of years.

    Bottom line, Saturated fats aren’t the problem.

  6. If we were to try and follow a paleo diet that closely resembles what our pale ancestors actually ate shouldn’t we be eating the majority of our saturated fatty acids from stearic acid, which is what predominates in grassfed meat and wild game? Stearic acid has no effect on serum cholesterol or triglycerides. What about lauric acid in coconuts, coconuts actually boost your HDL and lower your triglycerides.

  7. That’s why I eat my pound of daily bacon and eggs in the morning…

  8. Good to know about the collagen question. I had the same one. Thanks, Mark!

  9. “It says saturated fats disrupt the circadian rhythm and lead to metabolic dysfunction unless you eat them in the morning.”

    This is not specific to “saturated fats.” It’s generally commendable to eat your fats at breakfast and lunch. Your dinner, if you eat dinner at all, ought to be the lowest-fat meal of the day.

    1. Do you have anything to back that up please (genuine question)?

      I’ve read that you should focus your carb intake in the morning, because it’ll be burned by the day’s activity and may also lower morning cortisol levels if you’re stressed (that was via something the Hellers did), also that blood is slightly more prone to clotting immediately after wakeup, due to overnight dehydration & probably other effects (this was on a BBC page I can’t recall), so you might not want to flood your body with fat, especially in the presence of caffeine, a vasoconstrictor.

      In reality I eat things any old time, and don’t really intend to change that, though I find it easier to cut out carbs after mid-day, so I’m curious if there’s anything to support this. 🙂

      1. One of the reasons your breakfast should be high in fat is that in the morning, your gallbladder is full of concentrated bile waiting to be released. A low-fat, carb-heavy breakfast will cause only insufficient gallbladder emptying, while a relatively high-fat meal will likely result in a 100% gallbladder emptying rate, which is what you want (except if you have a gallstone or an acute bile duct infection, in which case limiting your fat intake is, unfortunately, a must). You can still eat fat at lunch but by the evening, your fat digestion will be rather poor, causing – as others have remarked from experience – a hard time getting a good night’s rest (think restless dreams). This can be interpreted as a disruption of your circadian rhythm.

        Most of this is based on the work of an Hungarian internist by the name of Peter Legrady who studied digestion. From his clinical practice emerged a set of dietary recommendations that emphasized 1) having 2-3 large meals instead of 5-6 smaller ones, 2) having a hearty breakfast with adequate amounts of fat, protein and fiber, 3) having a “balanced” two- or three-course lunch and 4) either skipping dinner – think of it as a way of intermittent fasting – or having a very light supper. He also recommended other things such as a regular consumption of eggs – which was considered heresy back then (the early 2000s) – eating pickled/fermented vegetables and other Primal-compatible things.

      2. It depends on ones health is in relation to cortisol which could dictate what (and when) they eat.

        As you stated Cortisol is higher in the morning. Cortisol is also inversely related to insulin. The higher the insulin, the lower the cortisol, Insulin wants to build up and store (hence delivering nutrients); cortisol on the other hand is catabolic (though it causes fat storage).

        For this reason, somebody with elevated cortisol will benefit from a carb heavy breakfast due to the insulin surge so to speak. It is better so eaten with protein as to slow down the surge so you have a gradual blood sugar rise/fall, along with a steady cortisol rise/fall.

        Cortisol in itself is a vasoconstrictor as it does narrow the arteries when the heart rate rises. Somebody with elevated cortisol, may not want to drink coffee in the morning; however, consuming fat will not cause any issues with elevated cortisol with regards to blood.

        It really depends from person to person and what your goals are but generally yes, carbs are best consumed morning and/or in and around workouts

  10. Based on the third question, I’m curious if there is a ration of carbs to fat that keeps unwanted weight gain to a minimum. I am a powerlifter and increased carbs a bit to keep up with that and I’m obviously trying to increase musclemass but would also obviously like to limit gaining fat!

    1. Hey Taylor, like you, I’m taxing my body (except by surfing, bodyweight exercises and some bike sprints). I dropped the carbs down and leaned out really fast. Then the low carbs started not working as well after a year or so. Nothing specific, just a general feeling that my carb intake was too low for my exercise level (carb cravings, maybe a little irritated, slower recovery time),So I’ve added more black beans, sprouted whole grain rice and sweet potatoes. I’m happier, and I’m still lean. I’m still an efficient fat burner and never bonk even though I do all my exercise before breakfast. I’m not even that hungry after working out. Just normal “no big rush to eat” hunger.

      I would do the same. Keep lowering the carbs over time until it reduces your quality of life, then notch it back up until you feel normal again. Then stay there. Once you become efficient at burning fat, it’s pretty easy to stay that way.

    2. Hey Taylor, weight gain/loss is tied to metabolism and circulating T3 rather an a relationship of carbs/fat (unless it’s relating to water retention). Thyroid secretes T4 which in turn either converts to T3 or Reverse T3 (RT3). T3 is the switch that allows your body to burn off fat and carbs/glycogen, consider it an accelerator to metabolism. RT3 is the brakes, and slows down the process. Lots of things cause T4 to convert to RT3; bad sleeping patterns, calorie restriction, intermittent fasting, low carb for too long, and just stress in general. Cortisol basically inhibits the amount of T4 produced by the thyroid.

      1. Brian,

        T3 is indeed made from T4 but a certain amount is made directly.
        A net carb intake of 50 grams appears to be a watershed when it comes to T3 production – go below that and your T3 will plummet, even in the short run.

  11. I’m with ya Shary and Elizabeth. I had my can of sardines for lunch. My wife (and pretty much my whole extended family) can’t stand the things. Sighhhh. They don’t know what they’re missing.
    Keep the blue side up.

    1. My family makes me open and eat them outside. Smoked sardines in oil over a bed of arugula with blanched red onion and lemon juice. They don’t know what they are missing.

  12. Happy to see another post in defense of saturated fats. Interesting idea though, them disrupting sleep. I drink whole milk all day long and don’t have any issues, though admittedly I have not thought of only drinking it in the morning. Haven’t had sardines in a long time, you guys have got me thinking about them now hah!

  13. I think it’s interesting that palmitic acid seems to be the lethal one if you’re a cell in a petri dish when palmitic acid is what the liver creates when trying to store excess carbohydrates as fat. In that situation, there would be no mitigating oleic or arachidonic acid to lessen the damage unless you always eat your carbs with olive oil.

  14. Great mailbag as usual … it’s great to deep dive into the specifics surrounding the Paleo/Keto diets instead of just hearing the basic “ Avoid carbs, eat protein” advice all the time.

  15. Haha. I think his spell checker turned “biology” into “bio cheese”. ????

    1. Or it’s the cheese that’s being made from culturing toe jam and pit funk.

  16. I normally find that if I eat something really fatty at the end of the day I have a harder time getting a good night’s rest. I try and keep fat to a minimum for dinner and later as a result.

  17. Mark,

    “because of the high-fat intakes, you will be insulin resistant”

    Wait a minute. Isn’t it an overconsumption of carbs that causes insulin resistance?
    What’s that got to do with dietary fats? Are there specific fat-carbohydrate combos / ratios that must be avoided?

    Admittedly, I have become a bit confused.

    1. When eating a keto diet this usually means the subject has lowered his/hers carb intake to below 50 grams a day. When doing this the body is not getting a sufficient amount of glucose to operate on so it switches over to fatty acids(AKA ketones), hence the word “keto”. At any rate the liver will produce enough glucose on it’s own to fuel the brain but that’s it. With negligible amounts of glucose in the body you naturally become insulin resistant. It’s not the same resistance as diabetic insulin resistance but can cause problems if you eat substantial carbs while in ketosis. I personally eat enough carbs each day to stay out of ketosis, eat at least 80 carbs a day to achieve this. Ketosis isn’t necessary to be healthy or to even lose weight.

      1. “….. Ketosis isn’t necessary to be healthy or to even lose weight….

        Depends on your individual physiology. For many people, ketosis absolutely IS necessary for weight loss, or even just weight maintenance. Many of us have learned the hard way that absolutely nothing else will work — not distance running, not sprinting, not powerlifting, not low-calorie, not low-fat, not anything else.

        In my case, I started running and weights and whole grains and beans while I was still a skinny teenager, hoping never to get fat in the first place. It didn’t work, as I got older the fat crept on no matter how hard I tried. Ditching the beans, lentils, and wholegrain bread in favor of more meat, fish, and olive oil was what finally did the trick.

        The discovery that ketogenic dieting — the polar opposite of the advice that the government, the medical establishment, and the vegetarian ideologues have been barking at us for the last 40 years — is the only thing that works for many of us, is a major driver of the alternative health rebellion. If they’re wrong about the most fundamental health advice — what to eat — what else are they wrong about?

        If you, personally, can control your weight without going keto, or only going keto cyclically, then, bon appetit. I’d never recommend keto to anybody who didn’t absolutely need it. But, there are a lot of us, perhaps a third of the population, in that category.