Starvation Mode - Adaptive Thermogenesis and Weight Loss

EvgeniZyntx

I’ve read many times that Starvation Mode is a myth or that it isn’t - while this irks me, it isn’t sufficient to push me to just add more noise to the debate. I recently read an interesting article that reviewed different aspects of adaptive thermogenesis, thinking it might be of interest to others, I’ve written a summary.

Broken into several posts, this covers the Starvation Mode Myth and Reality, some of the (mis)definition, then focus on adaptive thermogenesis and how it can affect real people trying to lose weight and hopefully some practical day to day aspects.

While I can’t guarantee you’ll learn something new, my intent is to present information that isn’t generally covered in an easy to read format and I know I learned something from writing this.

I hope it is useful to you.

Given the forum format, I’ve broken this into several posts and created in each a “too long; didn’t read” section.

I'll also thank the individuals that helped me get this together and, in particular LiftAllThePizzas, sjohnny, McB for by providing content input, questions or editing support.

EvgeniZyntx

What is usually meant by Starvation Mode?

The whole debate around “Starvation Mode” is that this term has taken a life of its own and through either exaggeration or inconsistent definitions resulted in a strange debate.

If you go and look at what is often called “Starvation Mode” you find:

I) “End of the World, You’ll Get Fat” - It means “the shutting down or crashing of one’s metabolism. This is often said to happen from having too little protein, too little calories or even from missing a meal. It is also said that your weight loss will plateau and you will not be able to lose fat because your body is starving and needs to hold on to anything it can. Some even say that you begin to gain weight as a result of your “ruined” metabolism.” (ref (1) – Oh, yeah, I’ll use references)

II) “72 hrs, only affects very lean, Minnesota!” - Or it “is a state in which the body is responding to prolonged periods of low energy intake levels. During short periods of energy abstinence, the human body will burn primarily free fatty acids from body fat stores. After prolonged periods of starvation the body has depleted its body fat and begins to burn lean tissue and muscle as a fuel source (2)” (This is from Wikipedia – an aside, the article the Wikipedia page references is a blog post and doesn’t even say that.)

III) “Long term adaptation” - Or when the term is the equivalent of “metabolic adaptation” or “adaptive thermogenesis” it can be defined as the metabolic and physiological changes that occur during weight loss that effect energy needs in a way that cannot be explained by the traditional BMR equations based on Lean Body Mass (LBM) and body composition. (3)

The “End of the World” definition is bananas. That is a myth and a good example of how good information becomes an exaggeration.

The 2nd definition of Starvation Mode is true but not really relevant to the average person dieting – however, for people on very low calorie diets (VLCD) for extended period this can be a concern. Gallstones, constipation are just some of the smaller adverse effects (7) Even for people just having a large calorie deficit. I’ll touch on this a bit later.

Then there is “Adaptive Thermogenesis”. This is not a sexy term and "Starvation Mode" sounds better. Alas, this Adaptive Thermogenesis concerns us all. As we lose weight, we need less energy to move around and if we lose some muscle along the way, well, our muscles use less energy in daily activity. But that isn’t all of it.
Adaptive Thermogenesis is a reduction in energy needs beyond the standard calculated needs from the amount of lean body mass. The person that lost weight needs less energy than the lean person at that same weight. It is complex; it is related to true changes in metabolic and physiological function and what I’ll focus most on.

By the way, when someone says that starvation mode doesn’t affect the obese or those with larger fat stores they are only correct in regards to definition (II). Adaptive Thermogenesis (III) especially affects people that have been overweight (3).

TL;DR Starvation Mode has different meaning to different folks. The idea of “I’ve crashed my metabolism because I didn’t eat lunch” is a myth. But other definitions, lean mass loss from extended low energy intake and adaptive thermogenesis from regular weight loss are scientifically supported phenomena. This last is likely important to you.

EvgeniZyntx

Starvation as Starvation Mode

Let’s get back to definition (II) This is usually where people write that it only occurs after 72 hours of not eating or references the Minnesota Starvation Study in order to minimize the concern or explain why no one is really in “Starvation Mode” and tout this as not being an issue.

Well, yes, if you aren’t stark raving crazy and cutting off your fingers you aren’t in the conditions of starvation like the guy in the Minnesota Starvation Study (6). Right? (wrong.)

There is actually a very good post here and I’m not going to focus much on that. (http://www.myfitnesspal.com/topics/show/761810-the-starvation-mode-myth-again)
Two things – the body is, in general, is a constant state of repair: building up and tearing down a variety of tissues like muscle and bone – dieting and the simple effect of carrying our weight on our muscles affects this balance. This is why astronauts lose significant amount of LBM (both muscle and bone in their case). Low calorie diets or diets with large deficits will push the balance towards less protein synthesis. These result not only in the loss of LBM (5) but there are other effects like malnutrition (10), very low testosterone levels(11) and psychological damage(6) and my favorite, sudden death(9).

That very low testosterone level? Loss of muscle mass and osteoporosis for men and women are just two of the significant complications of long-term low testosterone levels.


TL;DR That low calorie diet you or a friend is considering is a bad idea. Only under medical supervision for specific individuals and only for short periods of time should they be considered.

EvgeniZyntx

Why is it important? And the article review ... finally

Boy, I’m long-winded. Why all the interest in adaptive thermogenesis then? So far it’s a myth or not of much concern to most people. Let’s get to the meat – the part that affects most people, explains some of the difficulties in weight loss and suggests that we need diet breaks. This is getting back to definition (III) up above.

A review of a science review

As of June of 2013 an review article of some of the theories and research on adaptive thermogenesis in humans was placed in public access in PMC. “Adaptive thermogenesis in humans” by Michael Rosenbaum and Rudolph L. Leibel not only covers this research but also presents some points of interest in weight loss strategies.

There are interlocking control mechanisms, feedback loops, which work to maintain energy stores relatively constant without our conscious effort – the way these work is complex and the links between exercise, diet and the mechanism of appetite are not clear (ok, that’s basic, we are warming up. (4) )

Most diets fail (80-90%) and for those that are successful, maintenance will probably require “a lifetime of meticulous attention to energy intake and expenditure.” Well, that’s why we are all here, right?

So what happens when we lose weight? Well, the key eye opener phrase for me from this article is this. Read it and weep.

“Maintenance of a 10% or greater reduction in body weight in lean or obese individuals is accompanied by an approximate 20%-25% decline in 24-hour energy expenditure. This decrease in weight maintenance calories is 10–15% below what is predicted solely on the basis of alterations in fat and lean mass. Thus, a formerly obese individual will require ~300–400 fewer calories per day to maintain the same body weight and physical activity level as a never-obese individual of the same body weight and composition. Studies of individuals successful at sustaining weight loss indicate that reduced weight maintenance requires long-term lifestyle alterations. The necessity for these long-term changes is consistent with the observation that the reduction in twenty four hour energy expenditure (TEE) persists in subjects who have sustained weight loss for extended periods of time (6 months – 7 years) in circumstances of enforced caloric restriction in the biosphere 2 project, bariatric surgery and lifestyle modification.”

Wait, what? Repeat that?

Whether you go and live in a cave, get surgery or just change eating habits that 10% weight loss results in lower energy needs for 6 months to 7 years.

How does this work? The study goes to point out that:

- It’s not the work of digestion that changes (TEF)
- There is possibly a small change (10-15%) in resting energy needs (commonly called BMR or REE)
- The majority of the reduction in energy needs is around the non-resting energy expenditure – that is the energy used during exercise and in normal non-exercise activity.
It basically means you twitch less. Or you perform less physical activity (Other studies suggest that since physical activity doesn’t decrease – it increases in rats that lose weight. And logically people that lose weight by lifestyle changes are more active…)

So what is going on?
- Possibly muscles are more efficient? (lots of data that support that)
- Neuroendocrine function changes? (even more data that support that)
- Autonomous nervous system is affected and there is less “tone” of the sympathetic nervous system? – Let’s be reductive here – we twitch less? (lots of data for that)
- Brown adipose tissue (brown fat) is doing something? (early speculation and no clear evidence)
- Leptin, an important mediator in energy intake and use, is modified? (most certainly, but to what extend and what about the receptors…)

Let touch two of these in detail:

1) How are muscles more efficient?
It could be speculated that with people who were always lean, they didn't necessarily get there by exercising all the time, so their muscles didn't learn how to become efficient. Meanwhile, for a lot of people who get lean from fat, they got there by exercising and their muscles became more efficient in the process.

Several studies have shown that this is a very real observed reslut of leaning out and the possible mechanism is, aside from the speculation above, that there are actual changes in muscle physiology:

Here are the mechanisms the authors discuss (13):
- thyroid hormone changes affect proportion of muscle fiber types which in turn use proportionally different energy paths (fatty acid oxidation vs glycogen stores)
- possible changes in muscle fiber recruitment

2) What are these neuroendocrine changes? At the simplest level they correspond to increased adrenal activity and decreased thyroid and gonadal activity. This gets complex quickly and involves how hormones help regulate and balance things like activity, mood, hunger and body temperature and interact with the autonomous nervous system (the part of nervous system that works without our concious will). So what does increased adrenal activity really mean? Well, it results in an increase in appetite, reduced metabolic activity, and an increase in cortisol levels, which in turn result in loss of LBM and "increase the partitioning of stored calories to fat." (3) A variety of pathways such as those that regulate things from sexual drive to cognition to bone reconstruction are also modulated down.

Now, it’s really a mixture of all these listed things and the weight of each is interesting but how does this impact the average Joe or Jane losing weight?

In short one could imagine that metabolic, endocrine and autonomic systems are “fighting” the weight loss. This can be seen when Leptin is administered to subjects that have lost just 10% weight (neat table here (8)) the effects of weight loss on decreased energy expenditure, the autonomic function and the neuroendocrine function are reversed. (Great! Where do I get me some Leptin, right?)

TL;DR Losing weight creates a bigger impact on TDEE than you might think...

EvgeniZyntx

And in Practice?

1) Weight loss reduces TDEE in a way that is goes 10%-15% beyond what is expected from LBM. In order to combat this, it is either essential to maximize LBM during the weight loss process or one is likelier to struggle with that reduced calorie allowance.
2) Reevaluate working TDEE not from the equations but what you experience from tracking.
3) Take diet breaks and go to maintenance with the most calories that do not result in a weight gain when needed to reduce or recover the effect of adaptation. These diet breaks can be extensive (And this creates a logical framework for me for the Eat More to Loss process – if eating more “resets” the metabolism, then a loss will occur at what was maintenance)
4) Yes, there are factors that help create plateaus by increasing hunger, decrease energy expenditure and affecting various physiological functions: Understanding them and how exercise and diet interact will help in defining personal strategies for successful weight loss.
5) Success is measured in years, plan for it and adjust.

Finally, another bit of speculation - one of the reasons the bulk and cut cycles work so well beyond developing LBM, is that the refeed period of a bulk creates an efffecive diet break allowing for restabilization of hormonal and the other factors discussed...

Thanks for reading!

References, as promised.

1) http://fitnessblackandwhite.com/starvation-mode-myth-or-fact/
2) http://en.wikipedia.org/wiki/Starvation_response
3) Adaptive Thermogenesis in Humans http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3673773/
4) Interactions between physical activity and diet in the regulation of body weight http://www.ncbi.nlm.nih.gov/pubmed/10946787
5) http://www.ncbi.nlm.nih.gov/pubmed/2613429 (yeah, it’s a rat study, but are you paying attention? There are about two dozen studies on fat composition in humans htat say the same thing.)
6) http://psycnet.apa.org/index.cfm?fa=search.displayRecord&uid=1951-02195-000
7) http://ajcn.nutrition.org/content/34/4/453.full.pdf
8) http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3673773/table/T1/
9) http://ajcn.nutrition.org/content/34/4/453.full.pdf
10) http://www.ncbi.nlm.nih.gov/pubmed/15274764
11) http://www.ncbi.nlm.nih.gov/pubmed/22708619
12) Want to waste time and read a whole bunch of prior thread on this? http://www.myfitnesspal.com/topics/show/873075-starvation-mode-myth-or-fact?hl=starvation+mode+myth#posts-13147653
13) http://www.ncbi.nlm.nih.gov/pubmed/12609816

PepperWorm

Great tips. Thanks!

Ophidion

bump Good stuff! highest of fives for writing this thread and doing the research.

scottaworley

Metabolic adaptation =/= starvation mode.

ETA: While I think we would agree on the concept of metabolic adaptation, I think that it is dangerous to call metabolic adaptation "starvation mode".

sijomial

Fascinating – thank you.

ILiftHeavyAcrylics

Great post!



I love seeing research attached.

ST99000722

A great read , thanks for posting !
3 months in I did a diet break - a week netting maintenance - I file it under "can't hurt, might help".

LeanneGoingThin

Interesting, thank you.

almc170

Great post, thanks!

ElliInJapan

That's a great post, thank you for writing it! This whole "starvation mode" thing was always confusing to me. Are there any data whether this reduction in TDEE changes with time? (in terms of years I mean, assuming that the individual remains at the same level of leanness

ETA: Also, another question: what is considered a "large" deficit? (how is it defined?) I think VLCD are at ~800kcal, where do the so common 1200kcal diets fall?

_SABOTEUR_

This post is totally unsuitable for MFP.

Factual information backed up with research that you have actually referenced.

HOW VERY DARE YOU!

:laugh:

Thank you so much for this. It's a great read and I have learnt a lot. :drinker:

BeachIron

Thank you for posting this. :drinker:

Maaike84

thanks for this, very informative!!

Cranquistador

In.

MrBecky

Thanks!
A good read and thanks for referencing and laying it out so well!

BeachGingerOnTheRocks

Thank you for compiling all this together into one post. I do think "starvation mode" is an overused and misunderstood term on MFP, and it is very helpful to understand what it happening and why there is a real need for going slow with weight loss. Thank you!

ihad

Great writeup. This will be very valuable for many people.

EvgeniZyntx

That's a great post, thank you for writing it! This whole "starvation mode" thing was always confusing to me. Are there any data whether this reduction in TDEE changes with time? (in terms of years I mean, assuming that the individual remains at the same level of leanness

ETA: Also, another question: what is considered a "large" deficit? (how is it defined?) I think VLCD are at ~800kcal, where do the so common 1200kcal diets fall?

Thanks for the questions.

In the biosphere 2 study - It was found that at least 6 months after refeed, even when body weight had returned to normal, the TDEE was lower - but possibly this was due to the fact that the majority of the weight re-gain was fat.

http://ejournals.ebsco.com/Direct.asp?AccessToken=959Q5IJ8X14KKMU1XZMIQJKUUMR48IMJXD&Show=Object&msid=-419407123

For individuals that remain at the same level of leaness - there is this study:
http://ajcn.nutrition.org/content/88/4/906.full.pdf+html

The reduction in TDEE does recover and it is addressed in a lot the references they cite. But the duration, presence of TDEE drop, and recovery vary enormously and is a subject of discussion.

We previously reported persistent reductions in EE—corrected for metabolic mass and age—in subjects maintaining a reduced body weight for periods of >3 mo after cessation of weight loss (3– 6, 37). These reductions in EE could reflect transient carryover of the metabolic consequences of negative energy balance or could be a reflection of physiologic responses to reduced body fat per se (or both). The distinction between these 2 possibilities is critical to an understanding of weight homeostasis in human subjects.

The major finding of the present study is that there are similar, significant declines in TEE, NREE, and, to a lesser extent, REE in subjects maintaining a reduced body weight, regardless of whether that reduced weight has been maintained for weeks or years. In other words, bioenergetic responses to maintenance of a reduced body weight do not wane with time.

Studies in this laboratory and elsewhere have previously reported significantly reduced energy requirements in obese women who had maintained a reduced weight for periods of 4 to 6 y (1) and in subjects who were stable at their reduced weight months after substantial weight loss (38). Other studies did not detect significant changes in EE corrected for changes in metabolic mass in weight-reduced subjects (23–27).

A "large" deficit - yes, probably not clearly defined - VLCDs are diets that have calorie restriction to 800 cals. A large deficit is, I would assume, depends a lot on the starting point, duration, etc - I'm not sure there is a clear area here but let's say that anything beyond -30% TDEE is probably large. This is solely my assumption, I believe MFP goes with less and I welcome any references on this question.

EvgeniZyntx

Metabolic adaptation =/= starvation mode.

ETA: While I think we would agree on the concept of metabolic adaptation, I think that it is dangerous to call metabolic adaptation "starvation mode".

It might be, but this is what is often confused by these two terms both in lay terms and even in the scientific literature. If you have different non-overlapping definitions that correspond to how people use the terms - please go ahead and post them.

But the core of the info isn't about MA vs SM - I think that is a somewhat strerile debate but rather what is MA, what does it mean for the overweight person losing weight and how does it impact weight loss and do diet breaks help.

Camille0502

bump. Thanks for taking the time.

55in13

In any of these studies you looked at, was there ever a point at which lowering consumption did not increase the deficit?

The figures I had seen were in the 4% to 10% range, but accepting the study you found and referenced and bumping that up to 10% to 15% this means that someone eating at a computed deficit of 1000 calories below a 2500 TDEE may actually have a true deficit of only 625. I came up with that by subtracting 15% of 2500, assuming worst case impact on metabolism. A 625 calorie deficit should result in a loss of over a pound a week and certainly would not cause a plateau.

Jestinia

Joy. By the time I'm finally done I'll have to seek out a breatharian to learn how to maintain. Or at very least a CRONy.

nomeejerome

in to read later.

sunshine_gem

Bump to read again later. Fantastic post. Thanks!

dejamos

Bump. Thanks for doing the work on this!

djthom2

A lot to take in at once, marking it for a reread. Thank you for posting

EvgeniZyntx

In any of these studies you looked at, was there ever a point at which lowering consumption did not increase the deficit?

The figures I had seen were in the 4% to 10% range, but accepting the study you found and referenced and bumping that up to 10% to 15% this means that someone eating at a computed deficit of 1000 calories below a 2500 TDEE may actually have a true deficit of only 625. I came up with that by subtracting 15% of 2500, assuming worst case impact on metabolism. A 625 calorie deficit should result in a loss of over a pound a week and certainly would not cause a plateau.

Remember that your TDEE also reduces as you lose weight normally, then add to that the further reduction from a depressed metabolism.

Here, let's take someone like me as an example.

Starting at 110 kgs with a body fat percent of 30% and relative little activity results in a TDEE of 2650 or so.
A cut of 500 calories a day 3500 per week. Let's say I am eating at 2150 then.

After a while, this might result in a 10% weight loss to 99 kgs with an improved bf of 25% (not unreasonable if I did don't do much to conserve LBM)

The TDEE of the lean individual would be 2560 cals. What would be my depressed TDEE at this point? It would be about 2180 cals. Instead of having a deficit of 410 calories I would have only a deficit of 30 calories per day. Definitely "stall conditions" if I do not either "cut bigger" or work on LBM, take a pause, etc.

(You can do these calcs from the Katch McArdle equation using - BMR = 370 + 21.6 * LBM and TDEE = 1.3 * BMR)

One can always have a large enough deficit to avoid a stall - but can one mentally sustain it and is it worth the other effects on LBM, emotional, hormonal balance, etc.? I am not in these posts or others being prescriptive but trying to describe what happens.

ETA: By the way the study reports adaptation at "Maintenance of a 10% or greater reduction in body weight in lean or obese individuals is accompanied by an approximate 20%-25% decline in 24-hour energy expenditure" And we are only using a 15% decline...

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Doing very large cuts in calories does work - people here post the success of cuting down to 1000 calories and even my own brother decided to reduce to 1200 calories and he lost a lot of weight like that but this has other impacts. He lost without any effort to maintain his LBM and by his own words he "looks like poo".

I'm just looking at some of the things that happen along the way and why.

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Note that in the example I used above I can either increase my activity or retain LBM and that will hike up the TDEE in that example.

I should graph those out...