Metabolic Damage From Dieting

Read a really interesting article by Precision Nutrition on metabolic damage the other day which I though could spark some interesting discussion. Generally when I hear people talk about metabolic damage it’s some dude who’s dieted for like 8 weeks talking about how he needs to reverse diet (no, you don’t) and I roll my eyes, but this article had some interesting points about long term effects of hard dieting.

While I don’t think this applies to guys who go from a bit fat, or even quite fat, to lean, it does seem like it’s a concern for dudes who really push the envelope in terms of shreddedness.

So we all know that “adaptive thermogenesis” is a thing in the depths of a diet, with your thyroid, energy output, etc., all conspiring against you to make you burn fewer calories and keep a tighter hold on the fat you’ve got. What I thought was interesting (but also quite obvious when you think about it) is that the accompanying decrease in RMR is actually pretty significant, like 5-10%. So what this would mean is that if your weight sits comfortably at 180lbs, you are maintaining that weight on 10% more calories than someone who had to diet down to 180lbs.

The really fucked up thing about it is it seems to be a cumulative effect, with the loss of metabolism happening every time you diet. What REALLY sucks is that the effects can last for 7 fucking years! And it might even be longer than that because that’s just the longest timeframe that’s been studied.

So every time you do a contest prep or just lean out like a motherfucker, you are in essence losing 10% of your metabolism pretty much permanently! Anecdotally, I used to work with a dude who was an elite level (like world-class) Muay-Thai fighter. He walked around pretty soft, and said that it was because he had done so many crash diets to make weight for fights (he used to lose like 30lbs easy every time) that he just couldn’t lose weight anymore. And this dude knew what he was doing with his diet and exercise; he just couldn’t make the scale budge.

I suppose, in theory, the metabolic slowdown (or whatever you’d call it) would be offset by the increase in muscle mass you have hopefully made during your getting fat phase, but maybe not. That would be the difference between a proper bodybuilding offseason and just letting yourself get fat because you suck (like I do sometimes).

Would love to get some input from guys like @robstein, @BrickHead and @The_Mighty_Stu who have done several contest diets. Have you guys noticed yourself having to be stricter with calories at body weights you maybe once were maintaining with higher cals? What do you guys (or anyone else, obviously) think about this whole scenario?


Preach, brother.

ED, I’d love to get your perspective on this too.

I was full house-ish (~#210) until I decided to get bucket-list lean in the summer of 2011. Since then, I have tried to maintain a quite-lean physique (upper 180s) year-round, meticulously counting calories throughout. I had one episode of getting very (low 180s) lean (but that was not BBing contest lean) for a Physique show, then allowed my weight to return to the quite-lean level. At one point ~3 years ago my weight crept up to #200, but I was able to easily bring it back down to the upper 180s. For a long time, everything hummed along nicely.

Then ~1.5 years ago, my weight started creeping up despite no changes in either my caloric intake or perceived expenditure (ie, I was exercising the same amount). I began cutting calories/increasing cardio in response, but quickly found myself in a metabolic death-spiral. My BMR went from ~15 (circa 2011 through early 2015) to somewhere around 10 now.

Was this due to metabolic damage as per the Precision Nutrition thesis? Quite possibly, although I did not do multiple preps involving deep caloric deficits. Also, there is the confounding variable of my age. Now 55, it is certainly possible that I am experiencing a ‘normal’ metabolic slowdown. And of course, it could be due to a combo of these factors.

Will be interesting to read about the experiences of younger lifters; ie, those for whom my second variable is not in play.


For what its worth I suspect I have, to some or other extent, done this to myself.

Im a pretty muscular and pretty lean guy, 5’10 198 and ballparking 10% bf. but my maintainance calories are c. 2200 with me hitting the gym for an hour. 4-5 days a week.

I was, at 16, a pretty chubby guy, and have spent basically the last 10 years on a permanent cut and im pretty carb phobic as a result.

I can still lose weight, but it requires ketosis and/or sub 2k calories (I typically aim 1850).

Mitigating factor is that I sit at a desk all day for work and have a pretty long commute, so that 1-2 hours in the gym is my only activity (until bedtime :wink: ) and based on my parents, who both suffer from thyroid deficiencies, I wouldnt be surprised if I did just have a slightly slower metabolism than some.

But my ‘maintainance’ calories have slowly decreased over the years despite me maintaining weight and adding muscle.

All that aside some pretty scary stories, mosty from female BB and bikini competitors, where they diet sub 1k for prolonged periods and even 1-1.5k calories causes them to gain fat rapidly.


Thanks Yogi1 for bringing this topic to the forum. I also seem to be drifting toward metabolic creep after leaning out and staying lean, fit and muscular for months. I’ll be interested in the suggested remedies coming from this group.

I honestly believe that Layne created more problems for people by popularizing the term “metabolic damage” than any actual problem that exists in the fitness world.

Sure there are plenty of well written papers documenting why someone might suffer negative effects after a prolonged caloric deficit, but there are also plenty of very well written/documented pieces by very respected and knowledgeable individuals dismissing it as a total marketing gimmick.

Of course should anyone try to kill themselves by undereating, and overexercising for an entire year to see what happens, by all means -lol. There are certainly ways to suppress your natural hormone profiles, kill your insulin sensitivity, and just put yourself in a bad place,… but I remember Brad (@BrickHead) and I chatting a few years ago when I was reading about the Minnesota Starvation Experiment, and the effects of prolonged caloric deficits, and how the body is amazingly resilient.

For years I dieted for bodybuilding contests every Spring, and then would go up 25-30 lbs every “off-season” as I trained and ate in a more “normal” manner. Each successive contest season would, without fail, bring me a heavier stage weight (more lbm), with better conditioning, and was based on a dietary plan that entailed more calories and higher carb intake.

So, do I believe I damaged my metabolism? Not one bit.

Was I aware that I had lowered my bodyweight by the end of a contest prep and my general caloric requirements at that moment had adjusted as well? Yep

Did I pay attention to any possible skewing of my insulin sensitivity? Of course (some preps, I was careful reintroducing carbs because I had dieted on a lower amount, other preps I was like a furnace and could just keep throwing logs on the fire)



So you lost like 30lbs? You’d think that could cause some slowing of the metabolism, if it is indeed a thing.

True, it could all just be due to your body slowly withering away into what will presumably just be a pile of moth ball-smelling dust and harris tweed.

I kid, I kid, but if you’re maintaining now on BW x 10 that’s pretty brutal.

Do you have any in particular you could recommend?

This is pretty reassuring to hear, and I think that the most important thing is probably:

I’d guess that few people when ending a diet have the savvy to actually think about their calorie requirements post-diet, and would just jump into their old eating habits. You see it all the time.

Could just be another time when studies done on “normal” people don’t really apply to the serious weight training population.

It seems to make sense from a biological/physiological standpoint. If you routinely go through extended periods of living on a caloric deficit, it would be a logical reaction for your body to say “this keeps happening, it’s time to hold on to as much fat as possible permanently.” Our bodies have no idea that we have access to as many calories as we want in supermarkets and fast food restaurants. To a large extent, I believe, our bodies still function the same way they did hundreds or thousands of years ago when society wasn’t mass-producing food and agriculture was a drop in the ocean compared to what it is now.

@Yogi1 thanks for the tag and posting this awesome info, great conversation for the forums.

For me personally, this affected me significantly during the end of my preps. I don’t have stellar metabolism genetically anyway, so I have to really play some nutritional and cardio jujitsu to get stage ready, and most definitely feel the affects of my body adapting and holding on to that last bit of fat for dear life. Things like throwing in some 1500 calorie days, or doing 2-2.5 hours of cardio in a day a couple times a week, or lowering my low days to basement carbs but still having a solid re-feed are just a tools I had to whip out that other guys with faster metabolisms may not need to.

I have actually noticed the opposite effect after my contests were done and my body regulated back to normal. Right after a show, a smart reverse diet is important because the metabolism has slowed down and going right back to what your maintenance would have been prior to the prep is a recipe for disaster. But, after 8 weeks or so when I finally feel back to normal, I’ve noticed the ability to handle more carbs and overall cals while still maintaining better conditioning each year. My first year of contests I did two shows, had to do keto, lots of cardio throughout and low carbs throughout. Towards the end I really dug myself into a hole and responded well to adding some carbs.

My second year of contests, this past year, I was able to tolerate significantly more carbs and less cardio for the vast majority of my prep, no keto, and really had to lock it down the last 4 weeks into the first show. I came in 8 pounds lighter on stage but actually looked a lot bigger.

Now, between the first and second show this year was a 7 week stretch during which time I kept carbs lower and added cardio in an effort to dial in further, added in some 1500 calorie days and such, which was double edged as it helped me lean out more, but also put me on the brink of passing out a few times. Was it because my cals were too low and energy expenditure was higher than I thought? Was it a cumulative effect of dieting for over 20 weeks and still digging in further? Who knows, probably a combination of everything.

After my shows this year, once my body regulated, I was able to handle even more carbs, eating 350-400g a day and was able to maintain weight and conditioning, which at 160lbs and 5’4", is good stuff. However, I attribute that to the muscle I was able to put on during the past years of training and competing. Adding more LBM definitely allows for more carbs and cals, and I’ve been able to handle carbs better every year, compared to before I started training and my first few years of exercising.

This is another reason though I’m on the fence about competing this year. There’s no doubt in my mind that spending the better part of a year in a deficit, wrecking your body to get on stage, for multiple years in a row, will accumulate negatively on the body. For the guys that compete year after year, I could imagine that eventually the metabolism and certain bodily functions, hormone levels, etc., could suffer some long term damage.

One example, my wife and I recently went to a “Lifetime Fitness” that’s being built near where we’re going to move, and signed up to become members when it opens, receiving discounts and all sorts of good stuff. (Side note, Lifetime Fitness is freaking incredible, if there’s one near you, give it a look!) So, the guy giving us the tour is in his early 20’s and was talking about his most recent show. His coach, (get ready), had him on keto for 12 weeks, training 2-a-days, with the morning session consisting of fasted training, starting with 45 minutes on the stair master, (every day) then weights. Afternoon session was weights then more cardio. Now why the hell would any coach tell their client to train fasted, on keto, twice a day with an hour and a half of the stair master, is beyond me. There’s no way gym performance is going to be optimal, and ultimately I don’t think a bodybuilder will reach maximum stage potential if gym performance isn’t supported throughout the prep. This past year, even when I was at 1650 cals a day, I still got over 500 cals in my pre-workout meal to make sure I’d have a solid gym session. I would imagine that guy’s metabolism was pretty fucked for a while he was getting back on track.

This is more obvious in females and the symptoms they exhibit in a hard diet or prep, losing cycle, thinning hair, etc. It is possible to suffer long term and possibly permanent damage if females spend a long enough period (years) in a serious deficit and low enough body fat, so I would imagine males would exhibit comparative issues over time.

I read the article on Precision Nutrition website. Certainly some interesting points, and I can relate to a lot of them. I thought a lot of it was also some indirect advertising and plugging for their coaching services and other articles.

So, overall, my experience has been the ability to handle more carbs and cals after each contest prep. However, I did notice serious symptoms of metabolic adaptation during my preps. I think spending extended, very long periods of time in a serious deficit and low body fat levels could potentially lead to long term issues, but a well executed diet where one is only temporarily in that state, and under proper supervision of a great coach (thanks @The_Mighty_Stu!), doesn’t have much to worry about.


First time i really cut was last year, i lost about 6,5 to 7kg, but it was a really long slow cut. I remeber i started at 2500kcal and made a lot of progress then 2300, then 2100 then 1900 (my lowest) , problem is , after i finished the cut i was eating 2500 kcal back again to soon and came up to 2800.
Now im cutting again at 2000kcals already it seems waay harder, the scale moves super slow, most things i notice is thiner skin and i feel i as lean as i was eating 2300 or so in my last cut

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From a much longer and in depth write up by Alan Aragon discussing the myth of Metabolic Damage:

Because in no study that i have ever seen or ever been aware of has the drop in metabolic rate (whether due to the drop in weight or adaptive component) EVER exceeded the actual deficit whether in men or women. Fine, yes, it may offset things, it may slow fat loss (i.e. if you set up a 30% caloric deficit and metabolic rate drops by 20%, your deficit is only 10% so fat loss is a lot slower than expected or predicted) but it has never been sufficient to either stop fat loss completely (or, even to address the even stupider claim being made about this, to cause actual fat gain).

But even when the drop in metabolic rate is massive, sufficient to drastically slow fat loss, even when it occurs it’s only when that person’s body has more or less reached the limits of leanness in the first place. So for ‘hundreds of women who are self-reporting this in emails’ to a certain coach to exist, well; just let me call that what it is: bullshit.

@anon71262119 - women tend to be more susceptible to hormonal shifts as well as being biologically designed to hold onto a higher amount of fat, as well as water. IMO, having worked with many women over the years (bikini and figure competitors, crossfitters, powerlifters…) the fluctuations and having to track “monthly visitors”, and other issues that can have a very pronounce effect on water weight can boggle the mind!

If we’re talking actual clinical depression, it may be an issue triggered by a whole cascade of hormonal changes (I’m sure @BrickHead can go into real medical detail here). Of course we may simply be dealing with blood sugar issues, lack of full fat adaptation by the body, or a host of other issues that may merely seem like actual depression.

(I obviously cant say for certain, just throwing out some thoughts!)


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I just want to point out that while I quoted Alan above, I did so because I consider the man very intelligent in his study and interpretation of data and research. As such, his opinion (among others) on the whole “I can’t lose weight even though I keep cutting my calories, my metabolism must be damaged!” whining and use for advertising purposes speaks with quite a bit of weight. (especially to anyone who has actually read the real research on starvation studies and dietetics themselves!)


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That’s a hell of a post there, Rob!

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Pretty reassuring how the in-the-trenches guys on here aren’t observing any kind of metabolic slowing (I’m trying not to say “damage”) despite the severe cuts, and also the fact that you guys are au natural.

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do you subscribe to his research revue?





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yeah, but that dude’s so old he’s fucking haunted

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