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How We Get Fat

A while back, I did a Q&A about excess dietary protein and whether or not it could lead to fat storage.  The short answer was that, while the biochemical pathway exists, the likelihood of it ever happening are roughly zero.   For some reason, despite my answer being written in what I felt was a clear way, many people seemed confused.  Among other silly inferences, people somehow heard me saying that overeating carbs or protein can’t make someone fat.  And that was not true.  So to clear it up, let me look at the simple issue of how we get fat.

Energy Balance

.At a fundamental level, fat storage occurs when caloric intake exceeds caloric output and there is a surplus energy balance.  Now, I know that a lot of people claim that basic thermodynamics don’t hold for humans. Simply, they are wrong.  Invariably, the studies used to support this position are based on a faulty data set: to whit, they are drawing poor conclusions about what people SAY that they are eating.

For example, one popular book bases one of its many incorrect theses on a 1980 report suggesting that the obese ate the same number of calories as the lean.  Ergo, they concluded, obesity was caused by something else.  The problem is this, the data set is wrong.   This is a fact that we’ve known for 30 years but that the author was somehow unable to unearth in his “5 years of dedicated research”.

Study after study after study over the past 30 years shows people systematically under-report their food intake, by as much as  30-50%.  They also over-report their activity by about the same degree.  This means that they will say they are eating 1800 calories when they are really eating 2400 or more.   They overestimate the calorie expenditure of activity to as much if not a greater degree.  They think they are burning 900 calories when it’s closer to 300.

Because when you put those same people in a metabolic ward and control their food intake and activity, the energy balance always holds.  Always.  It’s only when you take self-reported data at face value that it doesn’t.

And make no mistake I am NOT saying that people are consciously or knowingly lying about their food intake.  Most people simply suck at knowing how much they are actually eating.   Lean people do it, obese people do it, active people do it.

Hell, even registered dieticians, who should be good at this, do it.  Self-reported food intakes are simply awful and wrong (which is a big part of why nutritional epidemiology is crap).  If you’re mistaken enough to believe the self-reported values, you reach even more screwed up conclusions about things.  Just like Gary Taubes did.

In that vein, I have found that the chronically underweight “I can’t gain weight no matter what I do” are invariably vastly over-estimating what they are eating.  That is, they are eating far less than they think.  Other studies show that “health conscious people” tend to under-report their true “junk food” and dietary fat intake.   That is, to appear healthier than they are, they selectively omit the burger and fries.  Honestly, if anybody is lying, it’s these folks.  Everybody else is just bad at this.

Nutrient Intake, Oxidation and Storage

The primary storage of fat in the body is in fat cells, duh.  Most of that is found in what is called subcutaneous fat, which is found under the skin.  There is also fat stored around the gut area called visceral fat (this surrounds the organs).  Fat can also be stored in “bad” places like the liver and pancreas under certain conditions.  This is called ectopic fat storage.

I’m going to focus here on subcutaneous fat.  There, whether or not fat is stored or removed comes down to a concept called fat balance, which I discuss in some detail in The Ultimate Diet 2.0.   You can think of fat balance as the fat specific equivalent of energy balance.  That is

Net Change in Fat Stores = Fat Stored – Fat Burned

The same nutrient balance concept holds for protein, carbohydrate and alcohol (which I will not discuss today).  That is, the net effect on bodily stores, whether protein or carbohydrate stores in the body increases, decreases or stays the same comes down to the balance of protein/carb stored vs. protein or carbs/burned.

So at a fundamental level, fat gain occurs when fat storage exceeds fat burning (technically oxidation).  And fat loss occurs when fat oxidation exceeds fat storage.  Please realize that both processes take place in some amounts throughout the day, controlled by a host of processes I’m not going to talk about.  Just recognize that what happens over time in terms of your fat stores comes down to the relationship between those two processes: fat storage – fat oxidation.

So what determines fat oxidation and fat storage rates?

Individual Nutrient Metabolism

And this is where people got confused in my previous Q&A about excess protein intakes.   And where things can get drastically unconfused if you’ll read this reasonably short piece on how nutrients are oxidized or stored in the body.    For those who didn’t read the linked article, I’ll summarize the key points below:

  1. Ingested dietary fat is primarily stored, eating more of it doesn’t impact on fat oxidation to a significant degree.
  2. Carbs are rarely converted to fat and stored as such.
  3. When you eat more carbs you burn more carbs and less fat.  Eat less carbs and you burn less carbs and more fat.
  4. Protein is basically never going to be converted to fat and stored as such.
  5. When you eat more protein, you burn more protein (and by extension, less carbs and less fat).  Eat less protein and you burn less protein (and by extension, more carbs and more fat).

Ok.  Let’s work through this one at a time.

When you eat dietary fat, it’s primary fate is storage as its intake has very little impact on fat oxidation.  A question that invariably comes out of this is whether or not people have to eat fat to burn fat.    And the short answer to that question is no.   Eating more fat does not increase the body’s use of fat for fuel under most conditions.  Additionally, dietary fat intake also does not impact much on the use of protein or carbohydrate for fuel.

Carbohydrates are rarely converted to fat (a process called de novo lipogenesis) under normal dietary conditions. There are exceptions when this occurs.  One is with massive chronic overfeeding of carbs.  I’m talking 700-900 grams of carbs per day for multiple days.  Under those conditions, carbs max out glycogen stores, are in excess of total daily energy requirements and you see the conversion of carbohydrate to fat for storage.  But this is not a normal dietary situation for most people.

A few very stupid studies have shown that glucose INFUSION at levels of 1.5 total daily energy expenditure can cause DNL to occur but this is equally non-physiological.  There is also some evidence that DNL may be increased in individuals with hyperinsulinemia (often secondary to obesity).  There’s one final exception that I’ll use to finish this piece.

But by and large the conversion of carbohydrates to fat for storage is not a major pathway in humans.   However, this doens’t mean that carbohydrate can’t contribute to fat gain.  Because when you eat more carbohydrates you burn more carbohydrates and less fat.  If fat burning is decreased, more of the fat that you are eating can then be stored as fat.   So the effect is indirect and I want to repeat it to make sure it’s clear.

Carbs don’t make you fat via direct conversion and storage to fat; but excess carbs can still make you fat by blunting out the normal daily fat oxidation so that all of the fat you’re eating is stored.  Which is why a 500 cal surplus of fat and a 500 cal surplus of carbs can both make you fat.

They just do it for different reasons through different mechanisms.  The 500 calories of excess fat is simply stored.  The excess 500 calories of carbs ensure that all the fat you’re eating is stored because carb oxidation goes up and fat oxidation goes down.  Got it?  If not, re-read this paragraph until it sinks in.

The same holds true for protein which is effectively never converted to and stored as fat.    When you eat excess protein and the body will burn more protein for energy (and less carbs and fat).  Which means that the other nutrients have to get stored.  Which means that excess protein can still make you fat, just not by direct conversion.  Rather, it does it by ensuring that the fat you’re eating gets stored.

How We Get Fat

I really want to make sure the above is clear before going forwards so let me summarize it even further.

Let’s assume someone is eating at exactly maintenance calories so they are neither gaining nor losing fat.   Now they create a 500 calorie per day surplus.

Let’s look at what happens physiologically based on where those extra calories are coming from.  That is, mechanistically why all three can end up making you gain fat.

  1. Excess dietary fat is directly stored as fat.
  2. Excess dietary carbs increases carb oxidation, impairing fat oxidation so more of your daily fat intake is stored as fat.
  3. Excess dietary protein increases protein oxidation, impairing fat oxidation so more of your daily fat intake is stored as fat.

Got it?  All three situations make you fat, just through different mechanisms.  Fat is directly stored and carbs and protein cause you to store the fat you’re eating by decreasing fat oxidation.

And I’d note again, since someone will invariably misread this that that doesn’t mean that a low-carb and/or low-protein diet is therefore superior for fat loss.  I’m not saying that and don’t think that I am.  Because in such a situation, while you may be burning more fat, you’re also eating more dietary fat.  So net fat balance can be unchanged despite the dicking around with macronutrient content.  It still comes down to the deficit at the end of the day and variations in carbohydrate and fat intake don’t tend to make much of a difference here.

Which also doesn’t mean that the choice of diet doesn’t matter at all.  It can depending on the context and I’ve done a comparison of the diets elsewhere on the site.

Why Not Just Eat Zero Dietary Fat?

Hopefully all of the above makes sense.  Basically, excess intake of all three nutrients can cause fat gain, just for different reasons.  Fat is stored directly and both carbohydrate and protein intake decrease fat oxidation so more fat is stored.

Which raises a fairly obvious question: If carbs and protein are rarely converted to and stored as fat, but can cause fat gain indirectly, wouldn’t a high-carb, high-protein zero fat diet cause zero fat gain?

And the answer is still no.  I mentioned above that DNL does not happen in humans under most situations.  Severe carbohydrate overfeeding can cause it but that tends to be rare.  But one time when DNL is upregulated in humans is when dietary fat intake falls below 10% of total daily calories.   Under that condition, carbohydrates can and are converted to fat for storage.   You’ll still gain fat.

Because the body is ultimately much smarter than we are.  When dietary fat intake is adequate (i.e. 10% of total calories or more), the primate fate of dietary fat is storage and protein and carbohydrates are used for other things.  And when dietary fat drops to an extremely low level the body will start converting carbohydrates to fat for storage.  It might even start converting protein to fat although I suspect that pathway is still pretty damn inefficient.

What About Alcohol?

And of course people are wondering about alcohol. Well alcohol is complicated and has to wait for another article.

But now you know how we get fat.

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99 thoughts on “How We Get Fat

  1. AWESOME article. Unfortunately, much needed.

  2. Lol, that’s a hell of a preface before you get to the substance. Who says you don’t have the elitist prick gene to make it inside the inner sanctum of speed skating? You should have fit right in. Thanks for the clarification.

  3. So basically what you’re saying is that no matter what you do, you are going to get fat?

  4. The flipside of this is the misunderstanding which leads to the idea that there is something special and particularly desirable (if fat loss is a goal) about remaining in the “fat burning zone” while doing cardiovascular exercise. More precisely, the misunderstanding here is twofold: It involves both an analogous misunderstanding of the implications of what substrate you are oxidizing while exercising and a misunderstanding of relative vs. absolute amounts.

  5. Great article!
    I think if people can’t understand it they have some degree of analphabetism..

  6. Great article. I had gathered that basic story from reading your articles, but it was nice to hear it more explicitly stated in this article. And I’m glad you discussed the “zero dietary fat” hypo, because that was I question I had.

    I look forward to the eventual article on alcohol – specifically, for instance, whether and how alcohol should be accounted for when I’m counting carbs/calories/etc; how alcohol affects fat loss, glycogen levels, and muscle gain; and all the other info I’m sure you’ll have for us.

  7. Lyle,
    This was fantastic…I understand why people were a bit confused by the last article. I ended up reading it through twice, after which I had a pretty good handle on what you were saying (I also read through the oxidation and storage article). This article, however, brings everything into perfect focus, thanks for the clarification and all your great work.

  8. so lyle this is more or less a homage to the energy equation?
    what do you object to people saying eating a certain composition of macronutritients set up a specific hormonal millieu that makes it easier to control hunger and therefore helps to lose fat.
    so would you agree that some macro compositions make it easier to reach a negative energy balance?
    or is that a completely different topic which people tend to mix up?

  9. Well presented and discussed Lyle. Now I understand the point of how protein will never be converted into fat.

  10. In a calorie deficit how much does the type of fat intake matter? I like eating saturated fat a lot more than mono. I know sat fat is more readily stored but obviously that would only happen in a surplus.

  11. So does this lead any credance to the “not combining fats and carbs in the same meal” brigade a ‘la Berardi? I always thought this was a pretty dumb idea.

    If my understanding is correct “no” would be the answer if in negetive energy balance (cutting), but what about bulking scenario’s?

  12. Aled: No, not in the least.

    Bilbo: Different topic.

    Jean Paulo: Thanks.

    Soultranfer: Good grief, did you not READ the introduction where I said NOT to infer a bunch of stuff, that when I say X I mean X and not to assume I mean Y. Or that you should read the articles elsewhere on the site where this has ALL been discussed? Thank for proving the point of my introduction by the way.

    August: If you overeat, yes, you get fat.

    Deo: Your part of the reason I had to write this piece with the introduction, because you and others can’t read worth a damn and insist on inferring a bunch of things that I never said. And then getting pissy when your mistake is pointed out to you.

    Because somehow you would take the sentence “This is a cat” and go “So Lyle says this is a dog” And then get bitchy with me when I said it wasn’t. Or had specifically linked to an article that said it wasn’t a dog.

    Which has nothing to do with being elitist. I’m just asking for basic literacy and to avoid being so lazy that you can’t click a link or read more than a single answer to a single question.

    But that’s apparently too much for you to handle. But instead of going “Yeah, I was wrong” you make it about me.

    But way to get indignant when you’re the one at fault here. And since this will be my last response to you, let me make it clear: please don’t waste more time whining in the comments section.

    If you don’t like how I roll, don’t read the site. It’s that simple, delete the bookmark and go find something else to read.

    Maybe T-nation would be more your speed.

  13. Lyle, you said it all. Two thumps up! This place is the best!

    And… I actually had forgotten the bit about sub 10% fat diets and the DNL ramp up. Thanks for the reminder! The body is surely a masterpiece.

    Looking forward to the article on alcohol. In vino veritas.

  14. how can someone get so grumpy over simple and honest questions.

    I appreciate that you adressed a question I posted in the comments before.

    The stuff about zero fat was new though

  15. This article should be in all forums of bodybuilding.

    The blame of this doubts it’s the tons of bullshit articles in internet (bodybuilding forums, articles, etc) and weigth-room culture.

    I guess most modern (not 0 day, say modern) research results were not transmitted to people, some part of the chain went wrong. I dont know if this thought that carbs are easily stored as fat was an old idea, or someone invented it using common sense.

    It’s not easy to change paradigms… if someone reads a lot of information that it’s not true, its very possible that when it reads things right, start associating wrong information with right information, and this conflicts appears.

  16. Doesn’t this really just say what most of us already know; you should eat based on what you need.

    All you gotta do is get enough fat, but not too much, so maybe 10-20% and then divide the protein/carbs up how you’d like as long as you are getting at least 1g/lb protein. Then it will just come down to calorie balance.

    Another more important question though, and I may be infering too much here.

    Are there delays in the processes of changing what is burned as fuel? Like couldn’t you take in NO fat on some days and cycle it often enough, as well as cycle the amounts of protein/carbs, to keep fat as the primary source of fuel with not enough dietary fat to supply energy needs?

  17. Good stuff Lyle. Very clear (I thought.)

  18. Does this mean it might be optimal for preventing fat storage to never eat fat and carbs in the same meal?

    For example,

    meal 1:
    fat and protein

    meal 2:
    carbs and protein


  19. Lars: Same answer as I gave to Aled that is about 2 comments above yours but you couldn’t be bothered to read. No no, a million times no. Food combining is voodoo bullshit.

    Dan: No that’s not what it says. Because nobody knows ‘what they need’. But you did make the mistake of making a poor inference, this article is NOT meant to make recommendations, I’m explaining basic physiology. No more, no less.

    So a tangent of ‘eat X fat and divide the rest or whatever’ has nothing to do with what the article is actually about. I wasn’t trying to make dietary recommendations in the least, I was attempting to explain some physiology and clear up confusion.

    And getting into your last question would take another full article to begin to address.

  20. Excellent article again Alumni Brother!

    Nice editing BTW 🙂


  21. Awesome Lyle!

    This article has more truthful information than almost any entire voodoo diet book.

    Keep up the good work.

  22. Awesome!

  23. My mother told me the other day that she is going on some sort of a separation diet because she has to cleanse her self and when I told her that that is not going to do sh*t she got upset.

  24. Lyle, you provide great information, as always. But you also LEAVE OUT a huge deal of equally great information. Let me explain.

    Your article is incomplete. You lay out all the interesting knowledge about fat storage, but in the end you don’t make a clear suggestion. You leave that for the (mostly uneducated) reader. So, in their attempt to reach the bottom line of what you said, people get confused. And it’s not difficult to see why .

    Correct me if I am wrong, but I guess that you do it on purpose, so as people will buy your books. Nothing wrong about that, but at least be clear.

  25. Alex: Jesus, could you be more wrong? No, you couldn’t. Every other issue related to application is ON THE SITE in one of the 200+ other articles. That you clearly haven’t bothered to read.

    It’s not to push a book at all and it wasn’t meant to be an article about application or I’d have discussed that. This was an article to explain basic physiology because people are confused.

    But thanks again for proving my point. You read a single article and drew a single stupid conclusion that is utterly wrong. I’ve discussed how to set up diets, compared high and lowcarb, how to adjust diets when they aren’t working in endless other articles here and my stuff is usually too long as it is.

    This was BASIC PHYSIOLOGY and that was it.

    Oh yeah, and fuck you for suggesting that I would leave out information to push a book. If I had been doing that, there’d have been one suggested at the end of the article but I don’t expect logic or facts to sway from your moronic opinion of me. Your going to draw your idiot conclusions based on this one piece and then get indignant over my comment here.

    Everything anybody needs to know to set up and adjust a diet is available in the FREE articles on this site. But you read a single one and like every other Internet illiterate, drew a moronic conclusion that is oh so wrong.

    Again, thank you so much for proving my point in spades. And did I mention fuck you?

    Martin: If food separation diets do anything, it’s this: most of the tasty stuff that people overeat is high in fat and carbs. By preventing those combinations, people are FORCED TO EAT LESS. Magic!

  26. Lyle, excellent job with this post. I feel your pain from some readers misinterpreting your previous post. You’ve made it very simple and clear now so everyone can understand. I’m glad you tackled this issue and revealed the truth. I can’t tell you how many times I’ve wanted to pull my hair out listening to “so called experts” say that eating more carbs or protein than your body needed automatically meant that it got converted to fat. The TRUTH has now been revealed. Keep up the good work!

  27. I ment in long term.

  28. Lyle, your site is by far the best thing on the internet concerning diet & training. I just want facts and truth and that is what you provide always. Because of your writings (I have read everything on the site) I have changed aspects of my diet and training, the results have been positve change (the proof). Thank you.

  29. Very helpful, thank you.

    Sometimes when I am out and about, with limited food choices such as
    during travel/vacations, I run into a problem deciding what is best when trying to maintain my body fat loss.

    I strive to always reach for a protein food first
    and lots of protein foods can be high fat (steaks,cheese, etc)

    if no lower fat protein foods are available, that makes me wonder whether
    I should just choose the lower fat carb food available?

    As an example, if the only food available to me at the time were a steak sandwich and I was trying to avoid weight gain, would I be better off just eating the meat and discarding the bread,
    or discarding the meat and eating the bread (since most bread has little fat)

    Obviously the best answer would be to never eat above my overall calorie needs, but I am thinking of situations where I might be exceeding those calories, for whatever reason (not simply gluttony)

  30. In this fast food serving society (i.e. instant gratification) unfortunately people just want to get a paper with a solution , (or just give me the pill) without investing time in undertanding how our body works and reacts to the input we give to it. Then you have people dissapointed because the “pill” they took does not work since they did not have the will to find first what their problem is.

  31. Enjoyed the article.

    I think one part of the confusion here is how people read your separation of EXCESS _whatever_ into EXCLUSIVE categories of fat/protein/carbohydrate.

    As long as one does not argue for any specific macronutrient ratios, if your calorie intake is excessive your fat/protein/carbohydrate would ALL be excessive (in terms of fat storage). Again, I’m not implying you claim you can have one without the other, I just wanted to point out that at least two persons in my flat read it that way 😉

  32. LOL! I think this whole article is halarious. What’s the point? If you do A then it will lead to B, and C to D… So now everyone wants to know the answer of how to burn and/or store more/less fat. But this article doe snot explain that at all. It basically says nothing relevent to the question on eeryones mind. Ha! Maybe I should just start ranting about something that does not give you any usefull info, and sit back and wait for everyone to take what they want. And then Ill get mad cause your confused

  33. Thanks for all the hard work, time and dedication you put into these articles, Lyle. It is MUCH appreciated!

  34. Great read

    This shoud be required reading for anyone working in the fitness, nutrition, or weight management industries.


  35. Ryan: Same comment as I made to alex. There are over 200 articles on this site dealing with application. Go read them. This was meant to explain one bit of physiology and if I made every article I wrote a comprehensive treatise, well…that would be called a book. And then someone else would bitch at me for making my articles too long. So stop whining.

    Erik: Excess = in excess of caloric requirements. That’s the bottom line: an excess of ANY caloric type can make you fat. But only if you are in EXCESS of your daily caloric requirements. But they still do it via different mechanisms.

  36. Excellent information.

    I am one of those people that others get pissed off at (secretly) I’m sure because I do what they are not willing or able to do that trounces this bizarre notions that there is some magic macro nutrient formula that makes some calories not count. lol. For years I have tracked the calories I consume as carefully as possible to make sure that I’m eating the right amount for my goal weight. I’ll shave off the necessary amount to lose fat when needed if I overindulge. That means buying the most accurate digital food scales and choosing, for the most part, the least processed foods so I am not as likely to be ‘off’ with the figures thanks to hidden ingredients. Sure, there will always be some margin of error, but if done carefully things shouldn’t be too crazily off.

    I’ve done this on different types of diets (meaning different macro nutrient ratios and foods). Whether I was about 14 years old (the first time I looked into this) or now, at almost 40 years old, it’s ALWAYS been about calories in vs out when it comes to fat gain/loss. ALWAYS. People want to believe that it’s something magical – the perfect ratios so they can eat their heads off and not gain fat. And yes, I’ve met many people who claim they are eating a little or a lot and said that they didn’t understand why they had gained or lost weight, and they were ALWAYS wrong when I broke it down with them and determined that, as you say, they were over or under estimated by quite a bit!

    I wish that strict metabolic ward studies were the norm when testing these things.

    Sure, I could eat the most when I was the most active because I needed perhaps an extra 500 calories daily so I wouldn’t lose weight thanks to the intense exercise I was doing (several hours worth!), but that meant a LOT of exercise because I’m only 5’1 and lean overall. I got tired of doing so much exercise, so I have a more moderate approach to exercise now and thus can eat a bit less (approx 1600 cals daily to maintain my current weight at current activity levels).

    I don’t mind weighing my food, etc. at all. I feel good that I can keep track of things and not run into the problems that others do when they are NOT being careful about keeping track of calories. Some people seem to have a good sense of how much they’re eating so they don’t need to count anything, but when I’ve tried that, I have either gained or lost weight when I didn’t want to. I do find that a diet that is moderate to low carb and medium to high fat is good for satiety, so that helps me keep calories at the right level without feeling hungry, and I do intermittent fasting sometimes, but truly, I’ve deliberately lost and gained weight on different diets, eating at different intervals (several meals a day, or only one big meal, eating at night only, etc) as long as the calories were supportive for my goals.

    Now, here’s something I’m still trying to figure out:

    Are people with low thyroid truly experiencing a lower metabolism or is their appetite being affected or is it partly edema that causes weight gain for them? I did have a weird experience years ago of dropping a lot of weight fast after days and days of eating lots of raw cruciferous vegetables. Now, my calorie intake was not high when I did that, but it did seem like I lost more than I normally would. My hair started to fall out and I was cold a lot during that time too. I won’t do that again – lol – but I’m genuinely curious if thyroid really affects metabolism like some people claim, or it’s very subtle. I know people who claim it does – they have thyroid disease – but I also know that they are eating more than they think they are to some degree and sometimes moving around less because they are so fatigued thanks to their illness.

  37. Good stuff as always Lyle.
    This is like a bunch of guys in trench warfare, watching as one dumbass after another climbs out and gets mowed down. Hilarious.

    oh btw, you forgot to include your super-secret 1 week method for fat loss, since i really hate reading or tracking food intake and besides, the gym is overrated…. 😉

  38. Perhaps people often misunderstand you not because they don’t read, but because you’re not clear. Ever stop to think that YOU might be the problem and not everyone else? A good writer does and even the best writers need editors.

    Given what you wrote, let me ask you a question. If my goal as your client was to get as fat as possible in 8 weeks for a movie I was making with Steven Spielberg called “Fat Man,” after figuring that my daily caloric requirements to keep me where I am was 2000, what foods would you have me eat in excess of my daily requirements? Remember you are trying to get me as fat as possible.

  39. Another great article that explains everything quite clearly I thought. This makes perfect sense to prove why practically all diets work at least in the short term. They all reduce calories-plain and simple.

    Thanks for sharing your knowledge with us Lyle


  40. eyes? opened!

  41. Hi Lyle……I have just read through your article and the information it contains is fantastic. The thing that struck me most though, is the comment on people reading things into your writing that you have not actually said! God, this strikes a chord with me.

    I know just how you feel , I try to explain things simply in terms people can understand about the thing I am trying to get across……..but deliberately or not they pick my comments into pieces and reassemble them in their minds to something that is nothing like the original statement. This is what makes simple things complex…… It changes from an accurate portrait into a Picasso painting of a face…..

    Try explaining why you are still bodybuilding at 54 and look twenty to your peers! They cannot understand that health and fitness are in some way linked, and that you look the way you do because you eat all the right things five or six times a day, do weight training and cardio fitness sessions…………No one listens then!!!

    Keep up the good work, I am still listening and not reassembling your thoughts LOL

  42. Lynn: calories matter, food combining does not.

    Lilea: Low thyroid does impact metabolic rate. A small percentage of people find that hyperthyroid can boost appetite but low thyroid status, to my knoweldge, does not impact on appetite. The water balance issue related to low thyroid status can mask fat loss.

  43. A study on fructose consumption increasing visceral adiposity and lipids by Jean Marc Schwarz ( is referenced by Robert Lustig, M.D. at a lecture to med students (available on youtube video – called “Sugar: the Bitter Truth” as a major contributor (fructose consumption) to childhood obesity. This is because the liver creates fatty acids in order to metabolize fructose, is what the research purports. Wondering what your thoughts are and if you have addressed this anywhere. Trying to separate fact from fiction in my research. Thanks

  44. I think Lyle has a right to be pissed off sometimes. He’s got a Master’s degree in this field, 15+ years’ experience, and offers hundreds of top-notch articles FOR FREE here, and people still argue with him and give him shit because of some B.S. they read somewhere else on the internet from a guy trying to sell them a crappy rehashed e-book. Or they think that because they don’t understand something HE must be wrong. This man has saved me hundreds of dollars (from not buying bogus supplements) and thousands of hours of time (from not doing unproductive stupid stuff in the gym). So thank you Lyle and please keep it up.

    and call me a brown-noser, I don’t care. :p

  45. Hi, Lyle, thanks for a great article!
    I looked and couldn’t find, are there studies that directly talk about this? Don’t get me wrong, I believe you, but I would like to have it printed as an “evidence”, because I’m a nutritionist student and one of my lecturers wrote exactly the opposite in hers handouts 😀

  46. Bojan: Directly talk about what?

    Paula: There is a research review on HFCS on the site and Lustig is an extremist. I’d suggest reading Alan’s deconstruction of what hew wrote. However, consider this: excess fructose can raise triglyceride levels. However, fructose doesn’t increase carb oxidation and fat oxidation stays higher. Guess what that means for the energy balance equation? It still stays balanced. And most of the ‘fructose’ studies use insane non-physiological doses of fructose.

  47. Diabetes Care. 1996 Oct;19(10):1142-52.
    High-fat and high-carbohydrate diets and energy balance.

    Shah M, Garg A.

    Center for Human Nutrition, University of Texas Southwestern Medical Center at Dallas, USA.

    The current American Diabetes Association guidelines for nutrition recommend a moderate increase in monounsaturated fats and a reduced intake of carbohydrate in patients with diabetes in whom high-carbohydrate diets deteriorate glycemic control and lipoprotein levels. High-fat diets, however, are believed to promote obesity, and some investigators may have reservations recommending such diets. This review thus investigates the role of diet composition in promoting obesity or achieving weight loss and its implications in patients with diabetes. Epidemiological studies show some evidence that fat intake is more importantly related to body weight than carbohydrate intake, but conclusions are weak because confounding variables, such as physical activity, smoking, and energy intake, were generally not controlled for. Metabolic studies under isoenergic conditions report no change in energy balance when fat intake is increased, but report a negative fat balance with substantial increase carbohydrate intake. During overfeeding, excess fat intake is stored as fat, whereas excess carbohydrate is mostly oxidized in the short term but can lead to substantial gain in fat stores because of reduced fat oxidation and considerable de novo lipogenesis in the long term. Spontaneous energy intake, however, is higher on an unrestricted high-fat diet compared with a high-carbohydrate diet, but the long-term effects are not known. Weight-loss intervention studies show that a hypocaloric high-carbohydrate diet is not associated with more weight loss than a high-fat hypocaloric diet. In conclusion, a high-monounsaturated fat diet to control glycemic control and lipoprotein levels in patients with diabetes should not affect weight loss or maintenance, provided that energy intake is carefully controlled.

  48. Fred – just lots of butter?

  49. Just a quick comment: anybody who wants to continue the argument about whether or not I’m an asshole can do it elsewhere. Further comments (whether pro or con) will be deleted. This is the only warning I will make.

  50. Lyle, thanks for Alan’s site and thanks for your continued commitment to health and wellness amidst the vast forest of silliness!

  51. Great article, thanks! Looking forward to the alcohol article… Logging works for me, as for Lillea, I don’t have the innate calorie check that some do, and it’s an easy, and unequivocal, way to see what is going on and what needs to be culled!

  52. Good article.

    Anybody who has messed around with macro’s in their diet order to lose fat will notice it comes down to intake.

    Also, just a reminder that fat loss and health are 2 different topics — let’s not blur the lines (or the goals).

  53. Your last point is a good one, and all too often forgotten.

  54. A study/studies that directly confirm Your standpoint, small to none possiblity of turning carbohydrates and protein into fat, are there any?

    One other thing. What if the excess of calories is larger than total fat intake of the day, and fat still covers 10 or more % of daily caloric intake (I didn’t calculate the example but I belive it is possible), that wouldn’t make extreme metabolic conditions You mentioned at which carbs and protein can be and are stored as fat? All the fat I consumed that day would be stored as fat, but I would still have the excess.
    Hope You understand what I’m saying 😀

  55. Bojan: Look about 3 comments above, review by Shah. And acutely, with fat below 10%, you simply see an expansion of glycogen stores. As i mentioned, it takes LONG-term overfeeding of carbs (like 3 days+) to see significant DNL. This is how UD2 tricks the body, for about 24 hours you can be above maintenance calories from carbs and not fat fat but ONLY if you keep fat low.

    Am J Clin Nutr. 1988 Aug;48(2):240-7.
    Glycogen storage capacity and de novo lipogenesis during massive carbohydrate overfeeding in man.

    Acheson KJ, Schutz Y, Bessard T, Anantharaman K, Flatt JP, Jéquier E.

    Institute of Physiology, Faculty of Medicine, University of Lausanne, Switzerland.

    The metabolic balance method was performed on three men to investigate the fate of large excesses of carbohydrate. Glycogen stores, which were first depleted by diet (3 d, 8.35 +/- 0.27 MJ [1994 +/- 65 kcal] decreasing to 5.70 +/- 1.03 MJ [1361 +/- 247 kcal], 15% protein, 75% fat, 10% carbohydrate) and exercise, were repleted during 7 d carbohydrate overfeeding (11% protein, 3% fat, and 86% carbohydrate) providing 15.25 +/- 1.10 MJ (3642 +/- 263 kcal) on the first day, increasing progressively to 20.64 +/- 1.30 MJ (4930 +/- 311 kcal) on the last day of overfeeding. Glycogen depletion was again accomplished with 2 d of carbohydrate restriction (2.52 MJ/d [602 kcal/d], 85% protein, and 15% fat). Glycogen storage capacity in man is approximately 15 g/kg body weight and can accommodate a gain of approximately 500 g before net lipid synthesis contributes to increasing body fat mass. When the glycogen stores are saturated, massive intakes of carbohydrate are disposed of by high carbohydrate-oxidation rates and substantial de novo lipid synthesis (150 g lipid/d using approximately 475 g CHO/d) without postabsorptive hyperglycemia.

  56. Lyle, I have to hand it to you. You make your point with rich well researched info. I’ve really gained a lot by poking around in here. Your stuff has helped me greatly.

    Thanks for not hording. I really appreciate your willingness to share your knowledge and hard work so freely…….


  57. A simplification of all this is to eat “with purpose” and not for “Pleasure”.
    Who was it, Jack LaLane?, that said, “If it taste good spit it out.”


  58. What a miserable way to go through life. Yeah, you spent 98 million years on the planet (LaLanne is at least that old) and you never enjoyed a moment of it because of some idiotic and trite approach to life. What utter bullshit.

  59. Wow! I guess that would be a choice. Sorry, for getting you so upset Lyle. But, don’t stress. (Remember the glucocorticoids thing). I doubt LaLanne cares what you think about him. After all, he’s happy, healthy, and living well in his 90’s and he’s never read anything you’ve had to say….hmmmm.

    Sorry I posted. I won’t again….just an occational read. As I said above, I do apprecite you sharing your stuff with all who care to read it.


    Find something you can be competitive at, it will help.

  60. Awesome post Lyle! A patient of mine just did the Lemonade Cleanse for 9 days and lost 14 pounds. After questioning him, he was consuming 300grams of carbs a day from maple syrup with no protein and no fat! What do you think happens when a person does this?

    If a person were to add sufficient protein to this mixture, would it be possible to avoid muscle loss in the short term?

  61. Good article. I think you should use it as your model article, in that you say just one thing in it without too much discussion or circling around the point. Lately you’ve been using a whole paragraph where a sentence would do.

    I understand that you’re trying to anticipate all the ifs and buts and whats you’ll get in comments, but remember that online people don’t read, they scan – so the longer the article, or series of articles, the MORE if and buts and whats you get.

    And then you have to write a rant.

  62. Lyle, amazing and insightful article. This explains why I have an intake of over 30% of my daily calories in the form of dietary fat (whole milk, butter, coconut oil, olive oil, nut butters, avocados), yet still manage to maintain my current weight or even lose some: my carbohydrate levels are below the RDA level, about 35-40%. Also in part because I exercise on a regular basis.

    Is that why Dr. Berardi recommends carb cycling? Sorry if this question is redundant.

  63. Carb cycling is a way of temporarily shifting fuel oxidation (e.g. reduce carbs and the body burns more fat) but it also usually affects caloric expenditure. That is, if you keep protein and fat static and cut carbs, you’re ina deficit. Since carb oxidation goes down, fat oxidation goes up. Fat loss occurs. But it’s not magic to carb cycling, it’s calorie cycling too.

    My own UD2 is just a more extreme version of carb-cycling strategies (e.g. 4 days lowcarbs -> 3 days higher carbs) with all of the physiology behind why it can be useful explained in detail there.

  64. Does the 10% dietary fat rule still apply if say, half of that, 5%, would be comprised of MCT’s or DG’s?

    For example: an individual consumes carbohydrates, protein, and 5% of the total caloric intake is MCT/DG and another 5% is animal fat.

    I’m assuming it wouldn’t mean anything towards stopping DNL that would occur as it would be made into ketones by the liver… but I’m just double checking…

  65. I can’t recall anything looking at it but I don’t see why it would matter. At the end of the day, I think a 10% fat diet is far too low for a natural bodybuilder. Parillo be damned!

  66. I would have to disagree that dietary fat is bound for storage. I am a 5’3″ female and eat over 100g of fat per day (mostly good fats, but not all.) The only fats I totally avoid are Trans Fats. On this diet I have gone from 29% body fat to 19% in six months. Daily caloric intake is 1800-2200 depending on amount of activity for the day. I basically do weight-lifting yet am very fit and able to do long distance running and cycling. A couple of weeks ago I did a 100-mile cycling event so I ate more to make up for the burned calories so as to not lose muscle. I didn’t eat a ton of carbs; I ate fat and feel my body runs better on it (has more energy.) That day I consumed over 5000 calories! The trick to it working like that is not eating the carbs with the fat. I am also insulin resistant and very carb sensitive (not from lack of eating carbs; I used to eat them daily like most people.) Now I have five high fat/high protein/LOW carb days followed by two high carb days and it just continues in that cycle. I am still losing weight and feeling fantastic. My cholesterol has come down nearly 100 points! So that is proof to me that dietary fat is NOT always bound to be stored. Metabolism is just chemical reactions. You can manipulate the metabolic pathways your body uses.

  67. You probably burned 5000 calories on the bike ride day so you were in calorie balance. Hence no fat storage. And I’ve addressed the issue of insulin sensitivity and macronutrient use elsewhere on the site, go find the articles and read them. But your examples prove nothing at all.

  68. This rocks – thank you for taking the time to write and share it!

  69. Geez, people. Get a grip.

    The point is that excess calories = weight gain. Operative word: EXCESS. Whether it’s good nutrients, bad nutrients, carbs, fats, protein, whatever, if you take in excess calories of it, you will get fat.

    You may have a preference for kinds of foods (don’t we all?), and maybe you feel like your body “runs better” on certain nutrients, but the point is you can overeat chicken, bread, or avocados, and if you don’t burn that extra calorie intake off, you will get fat! If you do burn the extra calories off, you will not get fat.

  70. What a riot! I love your style, Lyle! Glad I found this site. Thanks for the information.

  71. Wow thanks so much for your article! I loved how scientific it was yet also in laymen’s terms. I also enjoyed the “tude” in the article. It must be very frustrating to deal w/ certain individuals that tend to read into things “looking for the answer they want to hear..” Is your background in Physiology? Thanks again!

  72. just read you received your BS @ Ucla in Physiological Sciences. I was going to major in Physiological Sciences @ Ucla but decided against it after taking a couple of Sciences prereqs. Today is the first I’ve stumbled across your website.. I can’t express how stoked I am to read your articles! thanks again.

  73. Lyle,

    I was a fan of your articles just by the content alone, but now I’m becoming a bigger fan through your comments. You need your own TV show. Response to Alex, “Again, thank you so much for proving my point in spades. And did I mention fuck you?” Classic.

  74. It’s funny that I returned to this article after six months, and my name is mentioned right above.

    Nate, I agree that his response is classic. Classic sign that he is an asshole.

    Anyway Lyle, you state that “every other issue related to application is on the site, in one of the 200+ other articles, that I clearly haven’t bothered to read.”

    You idiot, of course I didn’t bother to read 200+ articles. I have other things to do (like actually training) besides sitting in a front of a computer all day like you do.

    You also say that if you were pushing a book, “there’d have been one suggested at the end of the article.” OK, there is not. Pardon me, you are so right. But, oddly, there are six book suggestions on the right side of your main page.

    However, the thing that bothered me most is your rude answer to my kind comment. But you can be sure that I’m getting laid alright. I don’t know about you though.


  75. If someone eats double their maintenance calories of 2500, made up exclusively of protein and carbs, then if fat intake is above 10% of total calories, (10% of 5000), will this mean de novo lipogenesis will not occur?

    In this case there is a surplus of 2500 calories, yet the implication is that only 500 calories will be stored as fat, which is the fat consumed for the day.

  76. Hi Lyle,

    First of all, thanks for the great article… lots of thought provoking information!

    I have a question: While you usually support your articles with sources, I noticed nothing supporting the following:

    “That exception is when dietary fat is below about 10% of total daily calories. Under that condition, the body ramps up de novo lipogenesis. So you still get fat.”

    Do you have some good studies you could point me towards that show this? (besides the single one upthread titled “Glycogen storage capacity and de novo lipogenesis during massive carbohydrate overfeeding in man”, I have already read that one).


  77. Wow…some of these comments clearly demonstrate why there is so much BS in the fields of nutrition and fitness…ignorance running rampant

  78. In terms of specific biochemical pathways Id like some support as to how carbohydrates cannot be stored as fat whereas fats are readily stored as body fat. To my knowledge it is glucose in fact that is the most readily stored as fat and the biochemical process of fat storage from fatty acids is virtually nonexistent in the absence of glucose. That is to say that in a theoretical 100% fat diet, the process of body fat storage would be minimal. Proteins can be converted to glucose by the process of gluconeogenesis and the product of which, glucose, can then be used in the synthesis of fat.

  79. your knowledge is wrong. In rats and mice, glucose is stored readily as fat. IN HUMANS, it is not except under extreme conditions of overfeeding. Google Mark Hellerstein and de novo lipogenesis. The pathways exist in humans; they are simply QUALITIATIVELY IRRELEVANT in humans except under extreme conditions. So put down Gary Taube’s book and learn.

    This is one paper of many many many papers. Key sentence:

    “The somewhat surprising finding that DNL appears not to be a quantitatively major pathway even under conditions of surplus carbohydrate energy intake, at least in normal adults on typical Western diets, is discussed in depth”

    The pathways exist. They are irrelevant and Gary Taubes deserves a bullet in the brain for his bullshit.

    Lipids. 1996 Mar;31 Suppl:S117-25.
    Synthesis of fat in response to alterations in diet: insights from new stable isotope methodologies.

    Hellerstein MK.

    Department of Nutritional Sciences, University of California, Berkeley 94720-3104, USA.

    Synthesis of fatty acids, or de novo lipogenesis (DNL), is an intensively researched metabolic pathway whose functional significance and metabolic role have nevertheless remained uncertain. Methodologic problems that limited previous investigations of DNL in vivo and recent methodologic advances that address these problems are discussed here. In particular, deuterated water incorporation and mass isotopomer distribution analysis techniques are described. Recent experimental results in humans based on these techniques are reviewed, emphasizing dietary and hormonal factors that modulate DNL and quantitative significance of DNL under various conditions, including carbohydrate overfeeding. The somewhat surprising finding that DNL appears not to be a quantitatively major pathway even under conditions of surplus carbohydrate energy intake, at least in normal adults on typical Western diets, is discussed in depth. Nutritional and metabolic implications of these results are also noted, and some speculations on possible functional roles of DNL in normal physiology and disease states are presented in this context. In summary, methodologic advances have added to our understanding of DNL and its regulation, but many questions concerning quantitation and function remain unanswered.

  80. Thank you for your prompt response. I actually do research on therapeutic fasting and ketogenic diet for glioblastoma, using mice. I was not aware that the metabolic pathways differed in humans and mice as significantly as they do. Thanks for directing me towards Hellerstein’s work.

  81. Great read…i was bored at work today and thought i would read another” Lyle Article” or re-read some of my faves. I had no idea it would be so entertaining.

    Your articles usually contain a large amount of information, information which is new to most, so i suspect some people don’t always remember all the details. I will admit, sometimes i’m one of them. I may end up going back through your articles 2 or 3 times, sometimes more, to ensure i understand what you’ve said. I would recommend this to all those who have questions at the end of an article, because the answer is usually there.

  82. Thanks for this interesting article. I’ve subscribed to your RSS feed. Would it in possible in the future to include some references to (scientific) articles? Or I might be the only one interested in that sort of thing – that’s because I have a weird and slightly diseased academic mindset 😉

  83. Hi Lyle, I’m curious as to your thoughts on the notion, commonly held by many scientists, that “a calorie isn’t always a calorie”? (Dr. Michael Eades for example?) It seems awfully simplistic to say Protein and carbohydrate have 4 calories/gram and fat has 9 calories/gram and leave it at that.

    Also, what about the fact (I say it’s a fact as it’s taught in university biology) that the ONLY thing that can be stored as FAT is CARBOHYDRATE. (since Carbs are the only thing that triggers an insulin response, and insulin dictates storage?) I’ve understood (but perhaps have it wrong) that it’s physiologically impossible to store dietary fat as fat.

    I’m prepared to be misguided on the above points, but am dead set against the simplistic notion that energy ingested must equal energy spent or not fat loss occurs. The idea that we’re SO efficient that we use EVERYTHING that we ingest is so mental that it makes me giddy. It’s never really been about how much we put in our mouths. It’s more about what ‘happens’ to the calorie/protein/fat when it gets into our system that matters, and this doesn’t negate thermodynamics, as it’s several steps before thermodynamics comes into play.

    So, about me…
    For a few years I was overweight 90-95k+g at 6ft, on a mesomorphic frame, while eating very little (one meal a day – after 9pm) and perhaps toast and coffee (+ milk) mid morning. I walked a lot, and quickly and spent most of my working day on my feet. I ate about a third of that (calorically and mass-wise) which my similarly sized friends colleagues ate, but I was more active. (I was almost always tired, foggy and slept poorly – duh).

    Basically, what happened was my body was in ‘Starvation mode’ and instead of using the calories I ingested and my stored fat for energy etc. it stored much of it as it was so long between meals, that my body literally didn’t know when it was going to eat next, and so decided I was in the desert and stored as much energy it could as fat, just in case.

    Conversely, when I was looking after my ill Mum, and trying to feed her up, I was eating with her, five times a day. (3 meals and snacks in-between). I ate around four times my usual amount of food, I was FAR less active, I slept about the same and my stress levels were about the same as when I was working in advertising, yet the weight fell off like tennis balls off an elephants back.

    So, your thoughts?

    All the best,

  84. Can you update the article with citations to your claims (i.e. hyperlinked text)? It would help with new readers (of which I am one).

  85. Lyle – just want to say thanks for all the free, informative articles. i could have pieced together 80% of what I needed on fat loss and dieting from your freearticles (e.g. fundamentals of fat loss) but I bought the keto diet book anyway to help support your work. I would encourage others to do the same.

  86. Saying you wrote 200 articles, go find them, isn’t very y helpful when your search function sucks and google only works if already know what terms to use. It is just laziness not to have an index of some sort. You always bitch at people for being lazy and then you don’t do something so obvious. Yeah it’s your site and if I don’t like it….but that doesn’t help people find the information that you spent time writing out. What good is the fact that you wrote it if only you and a few groupies know that it’s there? Constructive criticism, nothing more.

  87. Hello. Dear Lyle McD, I am feeling your frustration. Is it possible that some of the “reader confusion” which is driving you bonkers might have something to do with the use of the term “protein oxidation” here in this article?


    Carbs don’t make you fat via direct conversion and storage to fat; but excess carbs can still make you fat by blunting out the normal daily fat oxidation so that all of the fat you’re eating is stored. Which is why a 500 cal surplus of fat and a 500 cal surplus of carbs can both make you fat; they just do it for different reasons through different mechanisms. The 500 calories of excess fat is simply stored; the excess 500 calories of carbs ensure that all the fat you’re eating is stored because carb oxidation goes up and fat oxidation goes down. Got it? If not, re-read this paragraph until it sinks in.

    Oh yeah, the same holds for protein. Protein isn’t going to be converted to and stored as fat. But eat excess protein and the body will burn more protein for energy (and less carbs and fat). Which means that the other nutrients have to get stored. Which means that excess protein can still make you fat, just not by direct conversion. Rather, it does it by ensuring that the fat you’re eating gets stored.

    Of course protein also has the highest thermic effect, more of the incoming calories are burned off. So excess protein tends to have the least odds of making you fat under any conditions; but excess protein can make you fat. Just not by direct conversion to fat; rather it’s indirectly by decreasing the oxidation of other nutrients.


    Hope you don’t jump on me too for seeking the following clarification, but by “protein oxidation” do you mean “oxidation of the glucose which produced in the liver via gluconeogenesis using the by-products of de-aminating excess amino acids (which themselves result from excess protein intake)”?

    I’m not trying to be facetious here, I swear. My (limited) understanding is that protein is not directly “burned” in the same way as — say — glucose or fatty acids?

    I agree with you TOTALLY that excess protein intake — “excess” in the sense that it exceeds what the body can reasonably “store” in the form of skeletal muscle or otherwise use to maintain tissues and manufacture certain hormones etc etc — can lead to an increase in fat stores.

    Not by conversion to fats, of course, but rather, by the “blunting” effect on the use of carbs and fats for energy, due to the body utilizing energy — in the form of glucose — derived from excess protein.

    Okay. Here’s my question. To your knowledge, how strongly/ how positively do protein intake levels correlate to the amount of protein-derived energy which will be made available at any given time, as opposed to simply being excreted (the OTHER route for taking care of excess dietary protein)?

    This is the question which keeps bugging me, because — like just about everybody else here — one of my goals is to take in enough protein to optimize muscle gain, but without going to far and thereby tipping the balance toward a degree of “excess protein intake” which will increase my fat stores by too much.

    Here is my personal, individual, inexpert “approach” to my own protein intake: I suspect that in a Real Life scenario, and in the context of an “energy balance” which does not support obesity, a reasonably healthy, non-overweight person like me can probably get away with habitually consuming more protein than I need, “just in case”.

    Relative to, say, the habitual consumption of “excess” carbs or “excess” fats or “excess” calories in general. Unlike carbs and fats, as you already pointed out, energy which is ultimately derived from protein (as opposed to energy derived from carbs or fat) is metabolically expensive.

    If I’m not wrong, the “thermic” effect you mention in the paragraphs I’ve quoted refers largely to the metabolic cost of digesting protein and making it available for uptake as amino acids for the body’s structural, as opposed to energy, needs.

    What I am trying to say, in a clumsy way (sorry!), is that on the OTHER side of the process of digestion, there are further “metabolic costs”, mainly associated with what the body does with the by-products of de-amination (eg. manufacturing some non-essential AAs etc, using some of the by-products of deamination for gluconeogenesis, and — of course — converting the rest of the by-products of deamination into forms which can be safely excreted.

    As a layman, I think it’s not totally idiotic to wonder exactly how basic/ how central/ how direct and inevitable might be the path described as, “…eat excess protein and the body will burn more protein for energy (and less carbs and fat).” Lyle, that description may be sort of a bit sweeping, in the context of the… erm… for the rest of us, lack of general knowledge on the subject of protein metabolism?

    In a Real World scenario, of course. Given the relatively high thermic cost of using excess protein for the body’s energy needs, as opposed to the body’s structural needs, I imagine that it would take a very high level of “excess protein” to tip the body into “burning” a significant amount of “protein” for energy, well at least to a degree sufficient to make a significant dent in the burning of carbs and fat for energy? Here the word I would stress is “significant”; meaning, that I am sure that “protein burning” occurs every day in healthy people, under normal conditions, but not to a degree which has any significant practical — as opposed to theoretical — relevance to somebody who is concerned about “weight gain” in Real World conditions.

    No, you do NOT imply or state that this protein burning is ever in priority to burning carbs or fats for energy. I am just trying to get my own thoughts straight on this subject, the objective being to try and guesstimate the point at which excess protein intake really becomes “excessive” enough to contribute to fat gain in any meaningful sort of way… for me.

    We’re not disagreeing, right? I just want to make sure that I have understood your points correctly. Thank you so much for writing an article which very clearly NEEDED to be written in order to clear up many misunderstandings. Much appreciated.


  88. P/s: Lyle, I’ve just found the answer to my question in your book, “The Protein Book”:

    At page 9, 10:

    “Oxidation and catabolism of AAs in the liver have both an obligatory and regulatory aspect to them. Obligatory losses are those that occur as a consequence of normal body functioning and are considered constant regardless of diet or the body’s condition. They will not be discussed further since they cannot be affected by diet or training…

    …Regulatory losses are those that occur with changes in diet or exercise (exercise primarily affects the metabolism of AAs in the muscle and is dicussed in Chapter 3). In terms of diet, feeding has long been known to stimulate AA oxidation in the liver, especially when AAs in excess of requirements are consumed; oxidation of individual AAs has also been found to increase or decrease with increasing and decreasing intakes respectively. The various degrading enzymes up- and down-regulate in response to changing intake.”

    Oh. So AA oxidation in the liver is indeed the MAIN/ CENTRAL route for “excess” protein intake (“excess” in the sense of “excess to the body’s structural needs”)?

    In my comment above I didn’t mean to imply that proteins were something like “stevia” in the sense that excess is simply excreted without impacting the body’s energy balance (now that would be wishful thinking…), my question concerned how significant (or not significant) this AA oxidation might be — vis a vis fat gain — in the context of a healthy, Real World nutrition where the TOTALITY of energy intake (ie from carbs, fats, and proteins) matches global energy output fairly well.

    In my case, as an individual, I log my calories pretty accurately and I can tell that I tend to get away with maybe 30 – 50 g of what is probably “excess” protein in my daily intake probably because: (i) as a Southeast Asian my daily diet was probably a bit low in protein, anyway, and also because (ii) the satiating effect of proteins sort of filled me up a lot more even though the global calorie count remained unchanged; I really have no desire to eat more than my daily calorie target, it’s all I can manage to meet that. And then (ii) there is also the fact that deriving any calories from protein — as opposed to carbs or fat — is probably pretty inefficient.

    Thank you so much.


  89. P/s to the P/s (sorry!): Re-reading this article, all the comments by Lyle McDonald, and also that chapter in “The Protein Book”, I realize that for me, my confusion was over what “excess” protein intake means. I think that here Lyle McDonald means “excess protein in the sense of bringing the global energy intake beyond maintenance calories”, whereas I (wrongly) understood it to mean “excess protein in the sense of being excess to the body’s structural needs for protein”. Were that the case — and it is not, right? — I would not only have to be concerned about the balance between fat storage and fat oxidation, I would have to be worrying about trying to match my protein intake rather precisely to my body’s structural needs for protein. Hmm… sorry Lyle!



  90. I’m trying to reconcile your ideas with my experiences and understanding. I see no refutation of Lustig’s assertion that most fructose is converted to triglycerides. To me, fructose adds to the fat burden you describe, but your fundamentals remain sound in my mind.

    I see much room for Taubes’ claims that insulin prevents fat from being released so that it can oxidize. Will this imbalance make you hungry? Not likely. I have us talking an imbalance of 20-40 calories a day, hardly impacting hunger, at least not measurably in mice. Taubes’ understanding of calories is correct: quantity is not the cause. But his view that insulin is the evil pitchfork is misguided, at least somewhat. Insulin has no bearing on fat storage, only release.

    We’re talking assorted pressures with individual (YMMV) balance points. Fat as a fuel is secondary. Utilizing it doesn’t depend on fat burning enzymes but rather a reduction in priority fuels. Yet it can’t be a pure balance issue. If it was true, a simple calorie reduction would work, always. People would not be driven to overeat. IMHO the insulin effect must manifest at less than 100%. When serum insulin reaches x, then fat burning is not possible (or easy), regardless of proportions.

    I will keep reading your site. Good stuff!

  91. 3. “Excess dietary protein increases protein oxidation, impairing fat oxidation; more of your daily fat intake is stored as fat ”

    Example: this works only one day – starting with a state of total carb depletion

    1800 calories daily burn rate – me

    Food eaten:

    1000 grams whey protein(6250 calories)(242 included carbs – 225 carbs produced by glugogeneis)

    Half pound cheese – 1/2 cup sour cream – a little butter, cream cheese,(2500 calories)

    10 grams veggies

    This is what happens:

    Carbs eaten replace my state of carb depletion

    Twenty percent increase of Thermogenic effect from Protein is directly applied to the 700 excess calories of fat intake(above 1800 calories) –

    creating an energy balance(more or less)

    The calories from the Protein are completely ignored(the body burns any “excess” or excretes it

    This only works for one time – maybe one time per month with this high of a Protein Over-Compensation

    Next Day Results: Boy do I feel good – a general feeling of musle tightness and general well being – a loss all excess water weight

    I do not feel like I gained 1 1/2 pound from the 5000 or so calories over my 1800 needed to maintain

    I don’t eat meat – so for me – whey protein is a food –

    Eat like a lion – feel like a lion – if only one day per month –

    Over-compensating protein on a one or two days a week basis is too problematic – you have to start out carb depleted and carb deplete right after – and doing this weekly is just way too much trouble – one day a month is simple enough though and the protein over-compensation can be very high(1000 grams whey protein)

    I”ve read 80% of yor articles Lyle – I live in Orem,UT – do you still live in SLC ?

  92. Hi this article and webpage is fantastic, just got it linked from bodybuilding forum. Lyle you are a terrific “tutor” and your explanations are very clear and easy to follow. Dont waste your energy replying to people who argue with you about how well you do or dont explain stuff. Some people have lower IQ and thus comprehension capacty than others, no offense, thats a fact of life and you or they cant do anything about it. I do understand the article very clearly and it all makes sense on the basic level.

    I was the victim of general public “EXCESS CARBS ARE STORED AWAY AS FAT” fad diet propaganda until now. Now iam sitting here thinking about my diet plan and all starts to make much more sense after reading this article :))

    For last 15 days i embarked on a calorie and macronutrient counting diet with daily limits of 123g PROTEIN, 46g FAT, 222g CARB which is together 1794 kcal that is 20% below my TDEE of 2240 KCAL and let me tell everyone that 46g FAT a day for 80kg male is pretty low and i have big trouble staying below this limit almost every day even with my “fitness” diet which is much lower in fatty foods that average western daily intake of fat…

    Anyway now i understand what COULD happen if i increased my carb consumption to the point where it would completely cover my body energy needs every day… what WOULD happen than is that all those 46g of FAT would be stored every day (cause carbs would be burned to cover energy needs) leading to total of 1380g of FAT stored a month (46g * 30days) that is 1.38kg of FAT stored – imagine 6 BRICKS of butter stored around your belly every month…

    THATS HOW CARBS “MAKE” YOU FAT… its still the FAT that really makes you fat but eating carbs allows your body to store all your daily fat intake without oxidizing it, tens of grams every day, totaling towards 1.38kg of FAT every month because your body happily runs on carbs storing all fat in your belly or thighs…

    now tell me did i understand your article right ? i know food metabolism is very complicated interplay but i guess the basic principle i understood right, or did i 🙂

  93. Please will you read about the self experiment that Sam Feltham did to prove a calorie is not a calorie. He ate at least 5000 calories, the first time mainly fat and vegetables , lost weight. The second time processed carbs, the usual western diet, put on 10kg. Kept everything else the same. How do you explain that? Look him up. His website is SmashThe Fat

  94. Anecodote is not science.

  95. But studies showed eating high protein food will burn fat, as protein digestion is hard and take much energy

    can you elaborate?

  96. Protein burns energy in digestion. It does not ‘burn fat’.

  97. This is primarily a response to some of the readers comments. I used to agree with this line of thinking that in order to lose weight you have to expend more energy than you intake. This does not directly translate to losing more body fat though. A counter example I would like to hear people explain would be:

    – The double burden of obesity and undernourishment in the same household I.e. overweight mothers with starving children. These people do not have enough energy to live on. The children are starving and stunted, whereas the mothers are ‘distinctly fat’. Surely they are not consuming more energy than they are expending while their children are starving to death?

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