Calorie requirements for a thin person vs someone who lost weight to become thin.

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Replies

  • Alligator423
    Alligator423 Posts: 87 Member
    Apparently people who have lost weight have a lower NEAT (non-exercise activity thermogenesis) which is made up of little calorie burns like fidgeting. The body subconsciously is always trying to conserve energy after weight loss without you even realizing. I don't think there are/know of studies that follow people long term, so hopefully eventually this effect dissipates. One can hope!
  • kamakazeekim
    kamakazeekim Posts: 1,183 Member
    Not sure about the science but anecdotaly, I have seen this to be true. I know for a fact that I have to eat significantly less than other women of a similar height and weight in order to maintain my weight.
  • DeguelloTex
    DeguelloTex Posts: 6,658 Member
    Apparently people who have lost weight have a lower NEAT (non-exercise activity thermogenesis) which is made up of little calorie burns like fidgeting. The body subconsciously is always trying to conserve energy after weight loss without you even realizing. I don't think there are/know of studies that follow people long term, so hopefully eventually this effect dissipates. One can hope!
    I've read that this has been seen to persist for at least seven years. I don't remember the details, though.

  • senecarr
    senecarr Posts: 5,377 Member
    Outside of differences in lean body mass or activity level, the idea never makes a bit of evolutionary sense.
    If your body can just choose to use less calories, why would it ever use more? We evolved an upright gait, with all the back problems that go with and reduced speed, all to save 4 calories per km walking, but we have an energy saver mode we only turn on after we suffer our first feast then famine cycle? What?
  • DeguelloTex
    DeguelloTex Posts: 6,658 Member
    senecarr wrote: »
    Outside of differences in lean body mass or activity level, the idea never makes a bit of evolutionary sense.
    If your body can just choose to use less calories, why would it ever use more? We evolved an upright gait, with all the back problems that go with and reduced speed, all to save 4 calories per km walking, but we have an energy saver mode we only turn on after we suffer our first feast then famine cycle? What?
    It wasn't all to save calories walking. You can see farther upright and you can use tools more efficiently when you aren't using your hands for locomotion.

    You have to force your body to build muscle. It's not the default. I don't think it's that outrageous that the default isn't to be hyper-efficient unless circumstances nudge you toward it. It may well not be a zero-cost adaptation, even if it is a good adaptation to deal with less access to food.

  • eclenden01
    eclenden01 Posts: 12 Member
    You're underestimating the role of genetics. This study found that obese people burn 60 percent less calories than non obese people in response to exercise after taking into consideration body composition, just as an example. I think I remember seeing that some people burn 3 times as much per pound of resting lean muscle than others.

    http://rnd.edpsciences.org/articles/rnd/abs/2005/02/r5205/r5205.html
    erickirb wrote: »
    I would think this would have to do with the amount of lean mass the two people have. All things equal the one with the lower BF% would have higher caloric requirements. Other than that, there could be genetic reasons for the difference, though the amount should not be large, unless there is a medical/hormonal issue going on.
  • eclenden01
    eclenden01 Posts: 12 Member
    senecarr wrote: »
    Outside of differences in lean body mass or activity level, the idea never makes a bit of evolutionary sense.
    If your body can just choose to use less calories, why would it ever use more? We evolved an upright gait, with all the back problems that go with and reduced speed, all to save 4 calories per km walking, but we have an energy saver mode we only turn on after we suffer our first feast then famine cycle? What?

    Well, you could argue that people who weigh more already have more efficient metabolisms and that they just maintain these efficient metabolisms after lost weight. It's the skinny people whose metabolisms are inefficient. Then the famine cycle stimulates changes in hormones to encourage more feeding like the body has become used to.
  • DeguelloTex
    DeguelloTex Posts: 6,658 Member
    eclenden01 wrote: »
    You're underestimating the role of genetics. This study found that obese people burn 60 percent less calories than non obese people in response to exercise after taking into consideration body composition, just as an example. I think I remember seeing that some people burn 3 times as much per pound of resting lean muscle than others.

    http://rnd.edpsciences.org/articles/rnd/abs/2005/02/r5205/r5205.html
    erickirb wrote: »
    I would think this would have to do with the amount of lean mass the two people have. All things equal the one with the lower BF% would have higher caloric requirements. Other than that, there could be genetic reasons for the difference, though the amount should not be large, unless there is a medical/hormonal issue going on.
    Yeah, but my genetics were the same when I was having to eat half-gallons of ice cream to keep my weight up during two-a-days and when I was a fat tub of goo. I wasn't always obese.

  • erickirb
    erickirb Posts: 12,292 Member
    eclenden01 wrote: »
    You're underestimating the role of genetics. This study found that obese people burn 60 percent less calories than non obese people in response to exercise after taking into consideration body composition, just as an example. I think I remember seeing that some people burn 3 times as much per pound of resting lean muscle than others.

    http://rnd.edpsciences.org/articles/rnd/abs/2005/02/r5205/r5205.html
    erickirb wrote: »
    I would think this would have to do with the amount of lean mass the two people have. All things equal the one with the lower BF% would have higher caloric requirements. Other than that, there could be genetic reasons for the difference, though the amount should not be large, unless there is a medical/hormonal issue going on.

    Was this adjusted for fitness level? I would assume the "thin" person would have been in better shape, meaning their V02 Max would be higher (moving more oxygen), which in turn burns more calories. Fitness plays a huge role in exercise calories, when it comes to BMR I would venture to guess that there is probably no more than a 10-15% difference if same weight and amount of lean body mass, assuming same age, gender, height, unless of course one has something like Hypothyroidism or Hyperthyroidism, or PCOS, etc., due to genetics alone.
  • sticky130
    sticky130 Posts: 101 Member
    I think that somebody mentioned earlier about LBM after weight loss. I think too much emphasis is put on weight loss instead of fat loss, therefore when people reach their goal weight they are not aware of how much it effects their metabolism after losing so much muscle as well as fat. Think of people that are classed as skinny fat compared to people with a lower BF measurement, same clothes size but skinny fat weighs less. As their LBM is so different to the person with the lower BF will have a higher metabolism. Moral of the story is when losing weight concentrate of losing fat not muscle by strength training and feeding your muscles with enough protein. Think about what clothes size you want to be not what you want the scales to read.
  • eclenden01
    eclenden01 Posts: 12 Member
    I guess at the end of the day, it doesn't help much to dwell on genetic/metabolic disadvantage but I think it's important to recognize that those BMR calculators don't apply accurately to everyone... Some people are going to have to eat more or less than others at equal weight and it isn't always because they don't know how to use a kitchen scale.
  • DeguelloTex
    DeguelloTex Posts: 6,658 Member
    erickirb wrote: »
    eclenden01 wrote: »
    You're underestimating the role of genetics. This study found that obese people burn 60 percent less calories than non obese people in response to exercise after taking into consideration body composition, just as an example. I think I remember seeing that some people burn 3 times as much per pound of resting lean muscle than others.

    http://rnd.edpsciences.org/articles/rnd/abs/2005/02/r5205/r5205.html
    erickirb wrote: »
    I would think this would have to do with the amount of lean mass the two people have. All things equal the one with the lower BF% would have higher caloric requirements. Other than that, there could be genetic reasons for the difference, though the amount should not be large, unless there is a medical/hormonal issue going on.

    Was this adjusted for fitness level? I would assume the "thin" person would have been in better shape, meaning their V02 Max would be higher (moving more oxygen), which in turn burns more calories. Fitness plays a huge role in exercise calories, when it comes to BMR I would venture to guess that there is probably no more than a 10-15% difference if same weight and amount of lean body mass, assuming same age, gender, height, unless of course one has something like Hypothyroidism or Hyperthyroidism, or PCOS, etc., due to genetics alone.
    A 15% difference is the difference between a BMR of 2149 and 1826. 325 calories a day can make a pretty big difference.
  • eclenden01
    eclenden01 Posts: 12 Member
    erickirb wrote: »
    eclenden01 wrote: »
    You're underestimating the role of genetics. This study found that obese people burn 60 percent less calories than non obese people in response to exercise after taking into consideration body composition, just as an example. I think I remember seeing that some people burn 3 times as much per pound of resting lean muscle than others.

    http://rnd.edpsciences.org/articles/rnd/abs/2005/02/r5205/r5205.html
    erickirb wrote: »
    I would think this would have to do with the amount of lean mass the two people have. All things equal the one with the lower BF% would have higher caloric requirements. Other than that, there could be genetic reasons for the difference, though the amount should not be large, unless there is a medical/hormonal issue going on.

    Was this adjusted for fitness level? I would assume the "thin" person would have been in better shape, meaning their V02 Max would be higher (moving more oxygen), which in turn burns more calories. Fitness plays a huge role in exercise calories, when it comes to BMR I would venture to guess that there is probably no more than a 10-15% difference if same weight and amount of lean body mass, assuming same age, gender, height, unless of course one has something like Hypothyroidism or Hyperthyroidism, or PCOS, etc., due to genetics alone.

    Yeah, I dunno, I just pulled that study from nowhere. I agree that 15% seems realistic.
  • senecarr
    senecarr Posts: 5,377 Member
    senecarr wrote: »
    Outside of differences in lean body mass or activity level, the idea never makes a bit of evolutionary sense.
    If your body can just choose to use less calories, why would it ever use more? We evolved an upright gait, with all the back problems that go with and reduced speed, all to save 4 calories per km walking, but we have an energy saver mode we only turn on after we suffer our first feast then famine cycle? What?
    It wasn't all to save calories walking. You can see farther upright and you can use tools more efficiently when you aren't using your hands for locomotion.

    You have to force your body to build muscle. It's not the default. I don't think it's that outrageous that the default isn't to be hyper-efficient unless circumstances nudge you toward it. It may well not be a zero-cost adaptation, even if it is a good adaptation to deal with less access to food.
    Free hands for tools has generally been dismissed as putting the cart before the horse as far as I'm aware.
    Seeing far distances wasn't a concern, the fauna at the time that walking evolved would have been relatively low, and you can't see that much further on the horizon standing a few feet higher.
    It could be a combination of reasons, but the most compelling and explainable one is that 4 calories a km adds up enough to have the calories for one more child in a lifetime.

  • senecarr
    senecarr Posts: 5,377 Member
    BFDeal wrote: »
    senecarr wrote: »
    Outside of differences in lean body mass or activity level, the idea never makes a bit of evolutionary sense.
    If your body can just choose to use less calories, why would it ever use more? We evolved an upright gait, with all the back problems that go with and reduced speed, all to save 4 calories per km walking, but we have an energy saver mode we only turn on after we suffer our first feast then famine cycle? What?

    Your body adapts but either shutting functions down, slowing them down, or getting more efficient. I feel noticeably weaker when my calories are low compared to when they're high. Sure, walking around at the mall the difference is slight. Sitting at the weight bench not so much or riding my bike up a steep hill, not so slight. If your body didn't have these adaptations and you needed a set fixed amount of calories then even a relatively small deficit would kill you over time.
    You're comparing when your calories are low to when they are high, but that isn't the comparison. It is someone who was heavy and then lost weight, being at the same calories.
  • senecarr
    senecarr Posts: 5,377 Member
    eclenden01 wrote: »
    You're underestimating the role of genetics. This study found that obese people burn 60 percent less calories than non obese people in response to exercise after taking into consideration body composition, just as an example. I think I remember seeing that some people burn 3 times as much per pound of resting lean muscle than others.

    http://rnd.edpsciences.org/articles/rnd/abs/2005/02/r5205/r5205.html
    erickirb wrote: »
    I would think this would have to do with the amount of lean mass the two people have. All things equal the one with the lower BF% would have higher caloric requirements. Other than that, there could be genetic reasons for the difference, though the amount should not be large, unless there is a medical/hormonal issue going on.
    I see nothing in that abstract that states they have evidence for a genetic component to that difference.
  • eclenden01
    eclenden01 Posts: 12 Member
    senecarr wrote: »
    eclenden01 wrote: »
    You're underestimating the role of genetics. This study found that obese people burn 60 percent less calories than non obese people in response to exercise after taking into consideration body composition, just as an example. I think I remember seeing that some people burn 3 times as much per pound of resting lean muscle than others.

    http://rnd.edpsciences.org/articles/rnd/abs/2005/02/r5205/r5205.html
    erickirb wrote: »
    I would think this would have to do with the amount of lean mass the two people have. All things equal the one with the lower BF% would have higher caloric requirements. Other than that, there could be genetic reasons for the difference, though the amount should not be large, unless there is a medical/hormonal issue going on.
    I see nothing in that abstract that states they have evidence for a genetic component to that difference.

    Yeah, I def didn't pick a great example, but if they took into account body composition, what are the alternate causes for such a variation?