Why 1000/1200 calorie diets are bad - backed by science

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  • mahanaibu
    mahanaibu Posts: 505 Member
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    Title should say: Why 1000/1200 calorie diets are bad FOR SOME PEOPLE - backed by BAD science.

    It should really be "why losing weight while exercising is much better than losing weight without exercising."

    Well said. So the key is--don't let your physical activity level drop and building it up.
  • mahanaibu
    mahanaibu Posts: 505 Member
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    It appears to be a legitimate, randomized trial. But like any single study, it has limitations. The subjects were overweight, not obese, and previous studies have found that obese people tend to lose more fat on steep calorie reduction than overweight people do. Overweight people see more lean muscle loss. The two groups differ in other ways as well. There are also these restrictions that the researchers put on which subjects entered the study:

    "Participants were excluded if they smoked, exercised more than twice a week, were pregnant, lactating or post-menopausal, had a history of obesity (BMI>32), diabetes, cardiovascular disease, eating disorders, psychological disorders, substance abuse or regularly used medications except for birth control. "

    I understand the reasons for the exclusions, but keeping out people who exercise more than twice a week makes a huge difference in the kind of person in the trial.
  • volume77
    volume77 Posts: 670 Member
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    my eyes hurt
  • yarwell
    yarwell Posts: 10,477 Member
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    If only the cr+ex group was required to move, then how can the authors claim the other groups decreased activity because of their reduced calories?

    The decreased activity is done by difference, they know the TDEE from DLW, measure RMR etc and hence physical activity is the difference between TDEE and RMR plus TEF etc.

    The weakness of this approach is that the "decreased activity" is actually "decreased activity + errors + things we didn't measure"
  • yarwell
    yarwell Posts: 10,477 Member
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    I guess I have one question and one statement. I've dropped to 1500 calories, but don't plan going below that. Are any of the dynamics listed for the 1000-1200 calorie diet observed as high (or low) as 1500?

    The groups were on a 25% calorie restriction, 12.5 % calorie restriction and 12.5% extra exercise and a sub 900 calorie VLCD for a limited time (<3 months).

    So 1500 calories would have happened to people with a TDEE of 2000 on the 25% CR but the average TDEE was more like 2500 so probably only a few women on 25% CR got to 1500. So little evidence in this study to answer your question.
  • 55in13
    55in13 Posts: 1,091 Member
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    There is a famous study quoted in a lot of the newer nutrition books about a study made during WWII in which a group of men were put on a starvation diet for a period of time at......ready? 1000 calories a day.

    The most interesting thing I get from this study is that when they were again allowed to eat whatever they wanted many of them had become so obsessive about food they ate more than they did on average before the study, gained weight over their starting weight and some developed eating disorders.

    1000 calories is too low to allow for long term success for most people. Someone out there most know the name of the study I am talking about. I am pretty sure it is at least in the Gary Taube book (may have misspelled his last name) Why We Get Fat.
    Perhaps someone with a better memory than me can post more about that study.
    The MN starvation study. That is discussed ad nauseam around here. IMO, the biggest problem with it is they purposefully got them down into the starved range (BF% around 5) and kept them there for some time because they were trying to learn how to refeed starved populations. The physical and psychological effects of that were much different than a dieter going from overweight/obese to a more normal body weight. They saw as much as 40% dropoff in RMR, but only after their BF% was down in the unhealthy low range.
  • 55in13
    55in13 Posts: 1,091 Member
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    The MN starvation study. That is discussed ad nauseam around here. IMO, the biggest problem with it is they purposefully got them down into the starved range (BF% around 5) and kept them there for some time because they were trying to learn how to refeed starved populations. The physical and psychological effects of that were much different than a dieter going from overweight/obese to a more normal body weight. They saw as much as 40% dropoff in RMR, but only after their BF% was down in the unhealthy low range.

    Just stumbled across this looking for body fat info:
    A research paper by Gallagher et. al. in the American Journal of Clinical Nutrition (2000) came to the conclusion that certain low body fat ranges are “underfat”, which implies “unhealthy”. According to this research paper, men who are between 20-40 years old with under 8% body fat are considered “underfat”, whereas a “healthy” range is described as between 8-19%.
    This is what makes the MN study suspect to me. They didn't just lose into the healthy range then stop and try to maintain it. Some (most? these were conscientious objectors but they had to qualify for service and I think they still had to do basic training) of the participants started the study in a reasonably healthy state. It was not a study on weight loss; it was a study on the effects of starvation.
  • hollymartin90
    hollymartin90 Posts: 57 Member
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    This study is based on sedentary people I eat between the range of 1000/-1200 calories and exercise every other day (if not every day) it seems unlikely that this would result in decreased metabolism?
  • salladeve
    salladeve Posts: 1,053 Member
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    Everyone's an expert.

    Eating 1200 cal/day is so bad, I lost 80 lbs and have kept it off a year and a half. Its awful, don't do it!


    This is the best quote of the day, love it!
  • AnabolicKyle
    AnabolicKyle Posts: 489 Member
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    nvm...
  • Baba_Roxy
    Baba_Roxy Posts: 38 Member
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    wouldn't this be relative to the person?

    I feel that this sums up *almost* everything anyone says on this site, this post included.
  • jofjltncb6
    jofjltncb6 Posts: 34,415 Member
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    nvm...

    ^this
  • randomtai
    randomtai Posts: 9,003 Member
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    nvm...

    ^this

    +1
  • nelinelineli
    nelinelineli Posts: 330 Member
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    Another totally misunderstood article. And another pointless post.
  • SherryTeach
    SherryTeach Posts: 2,836 Member
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    Is there anything in that study that discussed calorie needs based on height, weight, and age? I'm guessing that my 5'1", 58-year old body doesn't need as many calories to maintain my current 102 pounds as a much larger, younger, and male person.

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