About 10 days ago I posted a Q&A titled Permanent Metabolic Damage dealing with the claim that, following extreme contest diets, bodybuilders and other physique competitors have ‘damaged’ their metabolic rate so irrevocably that they are able to gain significant amounts of fat consuming only 700-900 calories per day. I’ll let you read that piece to see my answer. But in the comments sections were several questions that seemed worth addressing although they weren’t all exactly related to the specific topic I was addressing.
Question: I suppose a follow-up question to this answer is just how rare it would be to cross a true “point of no return” where you may have fouled up your internal physiology to where it may never be able to rebound. Or is it usually a case of time and reversing some of the actions that cause it in the first place? i.e. the longer and more extreme the descent, the longer it will take to recover, but recovery is entirely possible
Would clinically severe eating disorders probably be the only instances where someone could allow things to devolve to such a degree that any sort of irreparable damage may have been done to some part of the body and its normal functioning?
Answer: First let me say that I am not and do not claim to be any sort of expert on the topic of eating disorders. It’s simply not been a major area of interest of mine. I think it’s worth considering that what is going on in something like anorexia or bulimia is quite different than what is going on with the topic I was primarily addressing in the original Q&A, to wit contest diets in bodybuilders/physique athletes.
For example, if nothing else we can see massive differences in the nutritional intake of a dieting bodybuilder/physique competitor (typically based around high protein intakes and ‘healthy’ foods) as opposed to the near complete absence of food in the anorexic or the alternation of binging and purging in the bulimic.
With that said, what little literature I have looked at in terms of recovery from eating disorders doesn’t lead me to believe that there is any sort of permanent damage. So long as a ‘normal’ weight is regained (here we’re typically looking at the anorexic), things come more or less back to normal. Even in the seminal Minnesota study, metabolic rate eventually rebounded to normal; of course the subjects had regained all of the fat they had lost as well for that to occur.
But again, this is really outside of my major sphere of interest; if anyone reading this has expertise that can contribute to this question, I think we’d all love to see it.
Question: Layne Norton once said that from the day one begins to eat normally again, it can take anywhere from 3-4 months to completely restore BMR to 100% from post-dieting levels. Although he didn’t cite it, do you know of any studies roughly reflecting this extended time frame? I’m only referring to restoration of normal hormone output and, thus, adaptive thermogenesis, since if the weight loss were maintained, BMR would still be relatively lower than it was pre-diet simply by virtue of a lower final body weight.
Answer: No direct research on this comes to mind immediately although it may exist. I think the problem is that, usually in looking at post-diet ‘recovery’ there is almost always a regain in body fat which tends to color the issue. For example, in the Minnesota study that I mentioned in the question above, following the 6 months of semi-starvation, the men were allowed to eat as much as they wanted. And they went nuts, eating massive numbers of calories and regaining fat. Which normalized metabolic rate eventually but doesn’t really apply to what you seem to be describing.
Frankly, I’m not 100% sure that hormones will ever return to completely normal (see next question) assuming that the lowered body weight/body fat level is maintained. They can be improved by raising calories to maintenance for sure. This is part of the rationale behind The Full Diet Break although that’s really meant to break up periods of explicit dieting (I also suggest it at the end a diet to start normalizing things). Which is a long way of saying “I don’t know” If Layne has a reference for that, I’d love to see it.
Question: So there is evidence of metabolic derangement, but do you think it is permanent even when returning to normal caloric intake?
Answer: The studies of the post-obese (see next question) suggest that, even at weight maintenance (i.e. when calories have been returned to normal), there is still a small overall reduction in basal metabolic rate (on the order of perhaps 5%) compared to someone who is ‘naturally’ of that weight. Meaning that if you compare someone who is 180 pounds without dieting to someone who has dieted down to 180 pounds, the second person will show a slightly reduced metabolic rate compared to the predicted values. But the effect is slight when calories are brought back to maintenance.
As I discussed in the original Q&A, it looks like the main impact in terms of reducing daily energy expenditure is on spontaneous activity levels; this probably explains why exercise seems to have so much bigger of an impact on weight maintenance than weight loss (as I discussed in Exercise and Weight/Fat Loss Part 2).
I am unaware of any research examining if this is maintained in the long-term (i.e. will the post-obese continue to show decreases in spontaneous activity). However, the long-term studies of the post-obese (ranging from 2-5 years if my memory serves correctly) suggest that the effect on basal metabolic rate never goes away. So yes, it’s effectively permanent; it’s simply small.
Question: I’m also wondering about the permanence of any such metabolic adaptations. It seems likely to me that metabolism would return to normal at some point. If so, how long would it take? It seems like I read something about this in a discussion of the Minnesota study, but I’d have to go searching to see if I’m remembering correctly.
Answer: As noted in the question above, what data I’ve seen looking at the post-obese in the long-term suggest that there is a slight reduction in basal metabolic rate that doesn’t appear to ever go away. At least not in any practical time frame. Based on what we know about the issue of setpoint (discussed in Set Points, Settling Points and Bodyweight Regulation Part 1) I wouldn’t expect this to ever truly go away. I imagine someone will ask the logical followup to this in the comments which is “So what about people who get and stay lean in the long-term, how do they do it?” Maybe addressing that will get me past my writer’s block to write an actual article about it.
Question: I am a clinical nutritionist at clinic where we see a lot of people with “screwed up metabolisms”. In a different vein, there are the people who got fat from overeating and eating the wrong types of foods and became insulin resistant. Now they have to eat low calorie diets otherwise they gain weight.
One of my clients weighs 360 lbs and her BMR according to the the InBody is 2700 calories. The girl eats maybe 1200 calories a day and maintains that weight. Reversing insulin resistance by eating the proper foods and incorporating resistance training obviously helps. I am wondering if there is an approach to increasing calories systematically when working to reverse insulin resistance without gaining weight?
Answer: This is really a bit outside of what the original Q&A was discussing but I’ll address it anyhow; certainly there can be metabolic derangements that occur in obesity (what’s cause and what’s effect is often hard to determine). However, it’s highly unlikely that your client is truly maintaining her weight on 1200 calories per day if her measured BMR is that high (meaning that her total daily energy expenditure is even higher); insulin resistance or not, that’s simply a physiological impossibility.
The more likely (and exceedingly common) issue is that she’s simply consuming more food than she’s aware of or self-reporting. Because even in studies of insulin resistance, when calories are reduced (and and accurately monitored), weight/fat loss occurs. So either she’s a physiological anomaly or she’s not really eating 1200 calories per day. And my experience (along with a large body of research) suggests that it’s the latter issue that’s the cause of the problem.
Thanks for the questions folks!
- Lean Body Mass Maintenance and Metabolic Rate Slowdown – Q&A
- Permanent Metabolic Damage – Q&A
- Bodyweight Regulation: Leptin Part 5
- Lean Mass or Total Weight to Set Calorie Levels – Q&A
- Nuts and Bodyweight – Q&A