Starvation mode is a myth!

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  • somerisagirlsname
    somerisagirlsname Posts: 467 Member
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  • LaneB89
    LaneB89 Posts: 93 Member
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    I'm inclined to believe that starvation mode is a myth, but aren't there quite a few scientific studies that lend themselves to the existence of adaptive thermogenesis? At least one study I read saw an energy expenditure of a full 30% less in a formerly obese person than a person who was the same weight but had never been obese, and this lowered energy expenditure persisted far beyond the period of dieting. 30% is quite significant - that's the difference between a healthy diet of 2000 calories and a sparse and frankly hard to maintain 1400 calorie diet.
  • Yagisama
    Yagisama Posts: 592 Member
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    I understand that the term "Starvation mode" is largely used incorrectly here and elsewhere.

    It's been a long time since I took biochemistry and nutrition classes, but I remember that metabolic pathway efficiencies would differ based on nutrient availability. For example, hexokinase/glucokinas affinity would differ.

    Basically, it's not that the body would stop losing fat, but that the body would be extremely efficient at storing fat and turning glucose into glycogen.

    That is what I've always assumed "Starvation mode" to be. Conversely if your intake is above a certain level, then there is a point that the enzymes are saturated and you will not absorb all of what you eat.
  • Jestinia
    Jestinia Posts: 1,154 Member
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    I'm inclined to believe that starvation mode is a myth, but aren't there quite a few scientific studies that lend themselves to the existence of adaptive thermogenesis? At least one study I read saw an energy expenditure of a full 30% less in a formerly obese person than a person who was the same weight but had never been obese, and this lowered energy expenditure persisted far beyond the period of dieting. 30% is quite significant - that's the difference between a healthy diet of 2000 calories and a sparse and frankly hard to maintain 1400 calorie diet.

    The study I saw was %20. But it's still enough to matter. Of course, if there is ever a famine, I know I'll starve at least %20 slower than most people who haven't been on a diet recently. And then I shall wait for them to expire and eat them.
  • GretaGirl8
    GretaGirl8 Posts: 274 Member
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    I am just going to refrain.

    deleted post.
  • livinatthegym
    livinatthegym Posts: 81 Member
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    Lol. I love this topic.
  • LaneB89
    LaneB89 Posts: 93 Member
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    The point is everyone claims that metabolic adaptation can't neutralize a deficit, while studies are showing that it can do exactly that. The most common weight loss target recommended is TDEE - 20%, and metabolic adaptation can cause you to burn 20-30% less calories.
  • csy108
    csy108 Posts: 58 Member
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    Doctors don't put people on vlcd because the likelihood they'll stick to it is nill.

    Presumably also because the people will fail to get essential nutrients, and because eating a prescribed VLCD will teach people nothing about healthy food choices for the rest of their lives.
  • dmenchac
    dmenchac Posts: 447 Member
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    The point is everyone claims that metabolic adaptation can't neutralize a deficit, while studies are showing that it can do exactly that. The most common weight loss target recommended is TDEE - 20%, and metabolic adaptation can cause you to burn 20-30% less calories.

    No, the point is 99.999999% of people who claim they are in adapative thermogenesis aren't even close.
  • rainbowunicorns720
    rainbowunicorns720 Posts: 48 Member
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    I read this yesterday in a much longer post but I hope a lot of people see this.
  • LaneB89
    LaneB89 Posts: 93 Member
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    Well, for starters, adaptive thermogenesis isn't something you're 'in' - it happens gradually as someone loses weight. The study I read that showed a 30% lower metabolic rate was testing a person who had only lost 50 pounds and was still large. The two subjects compared were a person who was 200 pounds but started at 250, and a person who had always weighed 200.
  • dmenchac
    dmenchac Posts: 447 Member
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    Well, for starters, adaptive thermogenesis isn't something you're 'in' - it happens gradually as someone loses weight. The study I read that showed a 30% lower metabolic rate was testing a person who had only lost 50 pounds and was still large. The two subjects compared were a person who was 200 pounds but started at 250, and a person who had always weighed 200.

    Link your study as you have not provided any time lengths or really any credible information.
  • Aaron_K123
    Aaron_K123 Posts: 7,122 Member
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    The point is everyone claims that metabolic adaptation can't neutralize a deficit, while studies are showing that it can do exactly that. The most common weight loss target recommended is TDEE - 20%, and metabolic adaptation can cause you to burn 20-30% less calories.

    You aren't going to go into adaptive thermogenesis of 20% eating at your TDEE -20%. You are going to go into adaptive thermogenesis of -20% while literally starving on a 400 calorie diet with heavy exercise as in the minnesota starvation experiment.

    So I repeat, there is NO point at which adapative thermogenesis compensates for your caloric deficit. Either your caloric deficit is small in which case adapative thermogenesis does not occur or it is huge in which case you get adaptive thermogenesis but adaptive thermogenesis cannot compensate for a huge caloric deficit.

    The idea that you can eat so little as to trigger adaptive thermogenesis and have adpative thermogenesis lower your metabolism so much as to completely compensate for your caloric deficit is a myth.
  • Aaron_K123
    Aaron_K123 Posts: 7,122 Member
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    You know its actually possible to calculate how much energy it takes to keep your body at 98.6 degrees (37 C) in a room temperature environment and its a lot. No amount of "adaptive thermogenesis" save death is going to compensate for that.
  • Jestinia
    Jestinia Posts: 1,154 Member
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    The point is everyone claims that metabolic adaptation can't neutralize a deficit, while studies are showing that it can do exactly that. The most common weight loss target recommended is TDEE - 20%, and metabolic adaptation can cause you to burn 20-30% less calories.

    No, the point is 99.999999% of people who claim they are in adapative thermogenesis aren't even close.

    Source please.
  • Jestinia
    Jestinia Posts: 1,154 Member
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    Whoops, I should post my source, too:

    http://ajcn.nutrition.org/content/46/4/622.short

    Obese women (140-180% of ideal body weight) were studied on a metabolic ward during 1 wk of maintenance feeding, followed by 5 wk of 800 kcal/d (liquid formula diet). Five subjects participated in a supervised program of daily aerobic exercise and three subjects remained sedentary. Total weight loss was not different between exercising and nonexercising subjects but significantly more of the weight loss came from fat and less from fat-free mass in the exercising subjects. Resting metabolic rate (RMR) declined similarly in both groups (approximately 20%), even though exercising subjects were in greater negative energy balance due to the added energy cost of exercise. In summary, results from this controlled inpatient study indicate that exercise is beneficial when coupled with food restriction because it favors loss of body fat and preserves fat-free mass.
  • vismal
    vismal Posts: 2,463 Member
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    Vismal, what have you started???
    It's about to get really real up in here! lol

    Thanks Aaron_K123 for holding down the fort while I was at the gym! Aaron is correct about adaptive thermogenesis. It will not wipe out a deficit because in order to cause it, the deficit must be HUGE to begin with. As I stated in the original post, prolonged VLCD or even regular dieting for that matter can cause slowdown (not shutdown) of your metabolism. There are ways to prevent this minor slowdown if you are worried about it. I always advocate a 2 week diet break for every 8-12 weeks you are in a deficit. By diet break I do not mean go HAM and eat everything in sight. I mean if you are eating -20% tdee then raise calories to your tdee. It gives the body time to rebound. I would also note that I don't feel that is even necessary if you have 50 or more lbs to lose. The diet break will also give you a mental break and something to look forward to while dieting.
  • martinel2099
    martinel2099 Posts: 899 Member
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    Very well thought out post, I never thought about it that way. I've learned something new today.
  • LaneB89
    LaneB89 Posts: 93 Member
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    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3673773/

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