Metabolic Damage and Reverse Dieting Debunked

This article started as a FB post in 2013 and has evolved multiple times since then. Here's the latest iteration:

It seems like the more reverse dieting gets debunked the more uneducated people i see advocating it. This blog will look at metabolic adaptation and the idea of reverse dieting from a research based perspective, as the Youtube videos on the topic seem to ignore all research.

1. Metabolic adaptation doesn't exceed 18% even in the most extreme situations. 18% was seen on biggest losers in this study.

Keys et al put men on 1500 calories for 6 months, they showed a 10-15% decrease (above what was expected due to lost mass), didn't stop losing until they were at 5%, and even then only stopped losing scale weight due to water retention. They never stopped losing muscle/fat.

Both of these studies used too low of protein, cardio, and no or not enough heavy lifting. These are all factors that could decrease adaptation.

So if metabolic adaptation doesn't explain why people maintain or gain on low numbers, what could it be?

2. People after a cut are very prone to binging. In Keys et al the subjects were literally fantasizing about food, all they thought of was food. After the 6 months they were allowed to eat as much as they wanted, and they went crazy. This can also be seen on many competitors Youtube channels. Most of us have seen a bikini girl talking about all the food shes planning on eating after her show at one time or another.

3. People are very, very bad at reporting calories. There was a study done on obese women who were having this exact problem. They were taught how to keep a food diary and instructed to record everything. They knew it'd be checked for accuracy. They were still wildly inaccurate, with one woman eating about 3x what she reported.

On a related note, some people will say "I've been eating x amount of calories and not losing," while they know they've been binging. A friend of mine said she was eating 800 calories and not losing in the a group. When i told her she was wrong about calorie intake a bunch of women jumped on me for "calling her a liar" and insulting her, and i got a pm from her saying she wasn't really eating 800, she was trying to and then binging a lot. Just like every other person that makes her initial claim.

4. If metabolic adaptation is caused by being in a deficit, why would you possibly stay in a deficit? If you put your hand in boiling water and it hurts, do you pull it out as fast as possible or do you lower the temp gradually? The idea of fixing a problem caused by being in a deficit by prolonging the deficit is ludicrous. There are negative adaptations brought on by eating in a deficit, and guess how you fix them? You stop eating in a fucking deficit.

5. Eating low calories increases cortisol, which often causes water retention. This can cause stalls on the scale. Adding in more calories can cause this water to drop.

6. Before moving on to the reasons reversing works and why, here's a post that shows some of the things Layne has claimed are not even close to physically possible. Layne's response to Avi saying its impossible was along the lines of "I would've agreed with you two years ago, but I've seen too much since then." For a man who claims he's of science, disagreeing with physics doesn't make much sense. It's also ironic that Layne admits there's no research backing him up, relying on emails from post contest women, but then demands research from other "gurus" on a regular basis.

I had a link to a post by Avi Bitterman on the topic but his fb is down. Here is the post though.

""Avi Bitterman added 3 new photos.
It's startling that whenever you point to the first law of thermodynamics to someone who denies "calories in calories out" or a proponent of "metabolic damage", they respond with some variant of "Well the body is not a closed system" or "the body is not an isolated system".

This is such a bizarre response. Obviously the body is not a closed or isolated system, if it were, no one would be able to gain or lose any substantial amount of weight as the total energy content within a body would have to remain a constant (for an isolated system) and the total mass could not change (for a closed system). This is an absurd scenario and has nothing to do with the objection at hand. Saying the human body is an open system just means that it is possible for the human body to gain or lose weight (ie: not requiring the human body to have a constant total energy content and allowing mass to be added or subtracted from the system) I'm not sure what relevant point this proves exactly.

Anyway, the first law of thermodynamics absolutely CAN be invoked to explain open systems, so long as it can be shown that said open system is within a closed system (EDIT: and if you are tracking the mass, it can be invoked even without it being shown that said open system is within a closed system - hat tip to Alan Carpenter for pointing this out).

For example, if an open system A is within a closed system B, the total energy content of system B must remain a constant. This means that caloric balance of A is completely predictable given enough data, since any output of energy from A to B or input of energy from B to A must be able to be predicted as they both add up to a constant value. Any work performed by A on B is measurable, and any calories consumed by A from B is also completely measurable.

This can be represented by a very simple formula:


Where Ai is the initial energy state of A
Bi is the initial energy state of B
Af is the final energy state of A
Bf is the final energy state of B

Thus change in the energy content of A *MUST* be offset by an equal and opposite change in energy content in B despite the fact that A is an open system. Also notice how you don't even have to know the value of C (the total energy content of A+B) to make these calculations.

The same thing applies to the human body:

Based on the first law of thermodynamics, in an open system (like the human body), the caloric expenditure from the system of the body to the system of the outside world and caloric intake from the system of the world to the system of the body can predict the caloric defect/excess of the system of the body, which is proportional to the weight loss/ weight gain. This is known as conservation of energy and the reason it works for this open system is that we can treat the entire universe as a closed system, requiring the conservation of energy during energy transfers from the body to the universe and the universe to the body.

Now, this doesn't mean the body will expend calories at a constant rate - and this may be the hardest part of the equation to predict, nor does it mean that metabolisms can't change over time, but one thing is for certain - the fact that the human body is an open system in NO WAY implies that the first law of thermodynamics can not be invoked to explain weight loss and weight gain given enough data."

7. Time spent reversing is time that could be spent bulking.

8. For all the people using anecdotes to back this shit up, read these. Anecdotes do not trump science, and you are not drastically different than other humans.


You Are Not Different

Why reversing seems to work.

1. More calories increases NEAT. NEAT is non exercise activity thermogenesis. It's all the calories you burn on a daily basis that aren't from actual exercise. Walking around, tapping a foot, etc. Homeostasis uses NEAT as a tool to maintain, when you eat in a surplus it's likely NEAT will increase, when you eat in a deficit it'll decrease. The degree of adaptation is highly variable on the individual. It has been observed it's common that people can have an "adaptive metabolism" as Layne and Menno called it in a recent "debate," and the degree of variation can be high both upwards and downwards.

2. More calories increases the thermic effect of activity (TEA), calories burned while training. This is also pretty obvious, you eat more you train better.

3. More calories increases TEF (thermic effect of food). This is also obvious, the more you eat the more that'll increase.

4. As stated above, more calories can lower cortisol and help drop water weight that's being held. Many times people will be losing fat in a cut and not notice until they add in more calories, and then not realize they aren't losing a lot of fat on the higher calories, they're just revealing the fat loss they already made by dropping excess water.

5. Reversing can be great to help ease the post contest blues, and most coaches who advocate it do it for psychological reasons. I used to agree with this. It'll slow down scale gains due to water and glycogen. However i also always thought it might be counterproductive in the long run. Competitors shouldn't feel like they need to stay stage lean after a show, it's not healthy. By reversing to stay as lean as possible as long as possible it really only encourages that mindset that one shouldn't gain weight after a show. In the long run its much healthier to learn to accept the water and glycogen gains without worrying about it, and if someone has serious issues with that they might need to be directed to a mental health specialist.

Alan said pretty much everything I've been saying for months and months in the latest AARR, read it. His final recommendation is very close to what mine has always been (mine was get to maintenance asap and sit there 2 weeks before bulking), don't take more than 2 weeks getting to maintenance and not more than a month before starting a bulk.

So the moral of the story here is that if you need help coming out of a cut don't hire a con-artist who'll just use myths to convince you to pay him $350 a month to get told you add 10g carbs and 5g fat every week, contact us and we can help you recover and maintain or get into a bulk the right way.



In a study layne was an author on they say that the benefits of reversing come from being in a slight surplus. It's clear that Layne's stated methods of reversing do not put anyone in a surplus in a reasonable amount of time.

"In theory, providing a small caloric surplus might help to restore circulating hormone levels and energy expenditure toward pre-diet values, while closely matching energy intake to the recovering metabolic rate in an effort to reduce fat accretion."

Layne likes to use the Chris Fahs case study as proof to his point. Here is a good post by Avi addressing that. Also its worth mentioning the subject in the case study was doing a dissertation at the same time as prepping, which obviously would add a lot of stress to the already stressful process. Here's a couple posts by Avi on the topic.

Re: That metabolic adaptation case report

Let's ignore all the problems that would suspect us that the metabolic cart was inaccurate (by the way, it wouldn't require 1217 calories per day, it would require MORE than 1217 calories per day just out of activity alone that 5 hours of strength, 40 minutes of HIIT, 30 minutes of LISS all PER WEEK would have to provide. 1217 calories would be needed just to keep him at the same weight during parts of the study, and the subject lost weight).

Let's also ignore that now this ~50% drop is being fully attributed to "metabolic adaptation" and none of that 50% is being considered as simply a decrease due to tissue loss, even if it is of small (but not insignificant) contribution.

Let's ignore all of this. These all come across as legitimate substantial weaknesses of a study, but nothing disingenuous.

This part though, is what really stood out (towards the end of the paper):

"Although randomized controlled trials are the norm in scientific literature, it has been satirically and accurately demonstrated that they are not always the best source of information.  We believe that our sample size of 1 is thus a strength of our study, as it enabled us to frequently perform a plethora of measurements for a full year in a difficult-to-study subject population."

Yup. You've read this right. A SAMPLE SIZE of ONE is a STRENGTH to determine metabolic damage in bodybuilders because you also don't need (and it's also not realistic to have) a large sample size trial to show that jumping out of a plane without a parachute is more dangerous than jumping out with one.

Why do they think this analogy is valid? Because "We are of the opinion that not many bodybuilders preparing for a competition would agree to regular fasted testing, maximal cycling tests, and maximal-strength assessments."

Firstly, simply because it's harder to gather evidence to support your position doesn't make your position any stronger with less evidence. Weak evidence is weak evidence. And a sample size of 1 should be recognized as just that, a sample size of 1. Granted, weak evidence is better than no evidence, but if the evidence is weak, the least you can do is admit the evidence is weak.

Secondly, the analogy is ridiculous. I get that it's meant to be comical. But I don't even think the illustrative principle applies that well either. The fact that jumping out of a plane with a parachute can improve your odds of surviving can be addressed using relatively simple principles physics. It's not a question of complex biology where it would simply be too unfathomable to calculate every variable that goes into a metabolic rate and thus one would need to resort to a study. The illustrative principle of it being difficult to get volunteers does apply, but it goes without saying that the magnitude clearly does not (as the degree of harm to the subjects is not nearly as comparable). -Avi

"Metabolic damage and deceptive partial representation. Here we go again.

So proponents of metabolic damage are now citing this study to support their claims:

And what do you know, the measured caloric reduction in RMR was double the predicted caloric reduction in RMR (617 vs 289). Gosh this is some pretty huge stuff and the stuff we've been saying about metabolic damage must have been wrong.

Well, not really. And with a little math it isn't too hard to see why:

Here's the data:

BLC group:
Baseline RMR: 2474
7 month RMR: 1857
Baseline predicted RMR: 2564
7 month predicted RMR: 2275

So simple math would show that 2564-2275 is a predicted drop of 289 for a predicted percent drop of 11.27% of baseline RMR based on body weight changes while what happened in reality was 2474-1857 = 617 drop for a percent drop of 24.93% of baseline.

But guess what, that also means that only 24.93%(actual percentage drop)-11.27%(predicted percentage drop) = 13.66% of baseline drop is attributable to actual metabolic adaptations not explained by predicted values from weight loss in the first place.

So basically this is just confirming what critics of metabolic damage were saying all along. That metabolic adaptation at most can only account for around a 15% (in this case it was 13.66%) of a reduction in metabolic rate.

Any reason why the proponents of metabolic damage didn't mention that part of the study?" - Avi Bitterman

Here's another critique of that study, referencing the metabolic cart issues Avi alluded to.

Layne Norton: "A lot of people have been claiming metabolic adaptation can only account for 15% of a reduction in metabolic rate. I would disagree with that. See this study done on a bodybuilder showing a reduction of almost 50% in metabolic rate over the course of a contest prep. It doesn't show it in the abstract but MR dropped from 2424 kcal/day to 1283 kcal/day."

Scott Landis Russell: "For those wondering, the weight change was from 102.85kg to 88.87kg. Then again, his energy intake was never far below 2500kcal, which makes me think the method of testing (metabolic cart) is probably inaccurate in this setting."

Layne Norton: "Scott Landis Russell you also have to consider his activity level"

Scott Landis Russell: "1200kcals of activity? Is that a joke?"

Scott Landis Russell: "Besides the study tells us his training. 5 hours of strength, 40 minutes of HIIT, 30 minutes of LISS. Per week."

Maurice van der Wardt: “Layne Norton: ''Keep in mind that I also don't think metabolic cart (oxygen consumption) is necessarily accurate. I've seen it tell people they had a metabolic rate of 2300 kcals but they were consuming far less and not dropping weight. I will step right up and say that I'm not sure where the disconnect is, but it's something else I'd like to study.''

1 mei 2013 om 22:19 [May 1, 2013 at 10:19pm]


Layne Norton: “Meaning I thought it overestimated energy expenditure.”

Scott Landis Russell: “Do you really think the bodybuilder in this study had a bmr of 1283 kcal/day? He was eating double that. That's not to say more severe metabolic adaptation isn't possible, but this study doesn't seem to support it.”

Layne Norton: “the data is what the data is. I'm quite confident in the ability of all the individuals involved in this study as they are all professors and well versed in measuring metabolic rate. The bodybuilder himself was a professor.”

Scott Landis Russell: “So you acknowledge that the metabolic cart might overestimate metabolic rate, but wont acknowledge it might underestimate it? And the data on caloric intake and activity also is what it is. Something clearly doesn't add up.”

Layne Norton: “sure it could be off, but this is going off my own observations and being around labs for a decade and involved with research. You seems to already have your mind made up regardless, so please feel free to continue to believe what you'd like to believe”

Scott Landis Russell: “Like I said, I'm open to the idea of more severe reduction in MR, but this study doesn't support it."

A couple more relevant threads that mostly go towards Layne's character.


I'm adding a part to touch on the "debate" Layne Norton and Peter Fitschen had with Eric Helms and Menno Henselmens hosted by Jeff Nippard. 

First of all I'd like to state that this was not a "debate." Some would use the word "roundtable," I prefer the word circlejerk. While Eric and Menno both made great points and presented the evidence well, they both refrained from calling Layne out on past claims he has made and even were very easy on him on very poorly debating his side during the "debate." They essentially just allowed him to backpedal and save face, letting it appear they agreed on most things, when in reality what Layne presents to the public when he has a block button to utilize is very different than the views he presented when he was being held accountable. He did everything from deflect (very often), cite rat studies whose relevance (even ignoring we're not rats) is questionable, and actually made some outlandish statements such as the obese often stall on low calories due to metabolic adaptation. The extensive research on vlcd's says otherwise. He references a lot of anecdotes, as he has ever since his initial "I have hundreds of client emails" fiasco. He talks about quantum physics and how he's a libertarian. At the end he shouts out his paid site. Eric and Menno did a great job giving good information, however they were way too easy on Layne when they could have taken advantage of this opportunity to put an end to this bullshit once and for all. Layne, when you inevitably read this (we know your ego is too big to ignore it), let me know when you'd like to debate me and Lyle on this, I'm sure he'd oblige.

I made notes as watching it on a thread in Lyle Mcdonald's facebook group, if you'd like to read them they are here. They're very candid, far from grammatically correct, and not very nice at times, but people found them interesting lol. My favorite quote from the notes is "layne attempts to initiate a sort of courting ritual with eric, eric hesitantly complies (if i cant win this debate at least i can make hearts with my hands and kissy faces to the opposition, thatll really show em.)"

Full notes HERE.

The video itself is HERE.