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Do you genuinely believe that metabolism doesn't vary across individuals, or for an individual over time? It differs a bit. Therefore, the problem is to find o

by Evgeny 11y ago

Do you genuinely believe that metabolism doesn't vary across individuals, or for an individual over time? It differs a bit. Therefore, the problem is to find out a particular individual's calorie requirements, which is achieved by carefully tracking calories and weight. I.e. if the weight is stable, we found this person's calorie requirements. Do you think the bodies of all individuals have precisely the same ability to both absorb calories from ingested food, as well as produce motion with the exact same efficiency? For weight loss purposes it is not so important. There is a top limit on energy to be absorbed, i.e 9 cal from a gram of fat. If a person only absorbs 8, good for him, but there is no way he will absorb 10. Do you believe enzymes present in the digestive system have absolutely no effect whatsoever on the calories in / calories out calculations? Again, there is a hard limit on how many calories can be extracted from a unit of food. Do you think every calorie you put into your body is converted into energy? For the purpose of weight loss, not so important. You digest only half of what you put in your body - good news, you can eat more and still lose weight. You digest everything - also no big deal. It's just that you cannot magically eat 1g of fat and suddednly gain 100g bodyweight from it.

mistermann 11y ago
You did a fairly decent job of discrediting your "the same thing will 'work' for everybody" statement. "top limit on energy to be absorbed" is one of those interesting statements that sounds like an answer and proof of something, but actually isn't relevant and is a dodge of the question I actually asked. Of course there's an upper limit to what calories can be absorbed from food, you can't consume that which literally isn't there - the question is, is is the caloric content that is actually extracted the same for all people (which is a subset of the question does the same thing work for everybody).
- Evgeny 11y ago
  You did a fairly decent job of discrediting your "the same thing will 'work' for everybody" statement. My "same thing works for everybody" is, in other words, "every person has a number of calories N, eating under which he will lose weight". I think I stayed pretty consistent. And yes, N may vary over time, but it still exists. the question is, is is the caloric content that is actually extracted the same for all people I can only restate that yes, it is different and no, it is not very important if our goal is weight loss. Suppose I extract 1500 calories from a meal, and you 1800 calories from the same meal. But the "thing that works for everyone" remains: you track your calories and weight, I track mine, maybe my weight is stable at 2000 calories per day, yours at 1700 calories per day. Then we just respectively start lowering our intake until we reach the desired rate of weight loss. Algorithm remains the same, we just plug in our own numbers. which is a subset of the question does the same thing work for everybody No, I can't see relevance. For lack of better example, all homes are different, some may have only rectangular rooms, some have oddly shaped rooms etc. So kind of "everyone is different". And still, anyone can easily calculate the space in square meters, or at least achieve a very close approximation for all practical purposes. So it does "work for everybody".
  - mistermann 11y ago
    My argument is that the calories in (eaten) / calories out (exercise) explanation, and the idea it is just that simple and if you're not losing weight you're cheating on your diet or lying about your exercise is wrong. You seem comfortable with the idea that different individuals have differences in caloric uptake (Suppose I extract 1500 calories from a meal, and you 1800 calories from the same meal), but I don't think others are comfortable with that idea. And if it varies across individuals, why is it impossible to vary with one individual over time, or change drastically in a short period of time? Can the physiology of your body change to (for example) start extracting more calories from food than it normally does? It doesn't seem like that crazy of an idea to me, and if it can do this (as anecdotal evidence suggests), then it makes weight loss strategies much more complicated, and it makes the simple calculations no longer work under all scenarios. This doesn't seem like a terribly controversial idea to me.
    - mikekchar 11y ago
      You can't extract more calories from food than their are. Calories are measured by actually incinerating the food and measuring how much heat it gives off. That is literally how much energy there is. So if you eat 2000 calories of food energy, you can not (if you are obeying the laws of thermodynamics) gain more energy than that. You can only absorb less. Similarly, as I said in a message above, there is a lower limit for how much energy your body must burn in order to maintain body temperature. You will find if you look at the rate at which corpses lose heat to ambient temperature that it is very, very close to what is listed on those base metabolic rate charts. Again, I have to stress this: you can not burn less than that without decreasing your temperature and dying. It is a physical impossibility. There are obviously variations, of course, but they must (by physical necessity) be on the up side. So you can easily eat 3000 calories and not gain any fat, even though you don't exercise, if you have a thyroid problem, or if you have a digestive problem that causes food to shoot through you before you can process it. On the other hand, you can not (due to the laws of physics) eat less than the number of calories required to maintain body temperature and not lose weight. This is conservation of energy. And as I said, the minimum amount of energy required to maintain your temperature is very close to those base metabolic rate charts. Sure you can be off by 100 calories a day. You can't be off by 1000. It just isn't possible. So if you are in deficit for several hundred calories a day and you aren't losing weight it is necessarily because you have measured your exercise or diet incorrectly. As I stated several times, this usually occurs because companies outright lie about how many calories you can burn through exercise (and are often off by 1 or 2 binary orders of magnitude). It is also because people completely overlook high calorie foods, even if they are otherwise very careful.
- leshow 11y ago
  > You did a fairly decent job of discrediting your "the same thing will 'work' for everybody" statement. Did you even read his post? A caloric deficit will 'work' for everybody by definition.
  - mistermann 11y ago
    A caloric deficit once achieved will work for everybody, but different people absorb calories differently - so, as was being discussed, the same thing (calories consumed per kg of body mass + exercise) will not work for everybody.
    - leshow 11y ago
      you keep harping on this 'absorbed calories' thing. and it's irrelevant to the discussion and not helping your argument. people have different caloric requirements doesn't mean that a some people magically can't turn body tissue into energy.

by Evgeny 11y ago

mistermann 11y ago

You did a fairly decent job of discrediting your "the same thing will 'work' for everybody" statement. "top limit on energy to be absorbed" is one of those interesting statements that sounds like an answer and proof of something, but actually isn't relevant and is a dodge of the question I actually asked. Of course there's an upper limit to what calories can be absorbed from food, you can't consume that which literally isn't there - the question is, is is the caloric content that is actually extracted the same for all people (which is a subset of the question does the same thing work for everybody).

Evgeny 11y ago
You did a fairly decent job of discrediting your "the same thing will 'work' for everybody" statement. My "same thing works for everybody" is, in other words, "every person has a number of calories N, eating under which he will lose weight". I think I stayed pretty consistent. And yes, N may vary over time, but it still exists. the question is, is is the caloric content that is actually extracted the same for all people I can only restate that yes, it is different and no, it is not very important if our goal is weight loss. Suppose I extract 1500 calories from a meal, and you 1800 calories from the same meal. But the "thing that works for everyone" remains: you track your calories and weight, I track mine, maybe my weight is stable at 2000 calories per day, yours at 1700 calories per day. Then we just respectively start lowering our intake until we reach the desired rate of weight loss. Algorithm remains the same, we just plug in our own numbers. which is a subset of the question does the same thing work for everybody No, I can't see relevance. For lack of better example, all homes are different, some may have only rectangular rooms, some have oddly shaped rooms etc. So kind of "everyone is different". And still, anyone can easily calculate the space in square meters, or at least achieve a very close approximation for all practical purposes. So it does "work for everybody".
- mistermann 11y ago
  My argument is that the calories in (eaten) / calories out (exercise) explanation, and the idea it is just that simple and if you're not losing weight you're cheating on your diet or lying about your exercise is wrong. You seem comfortable with the idea that different individuals have differences in caloric uptake (Suppose I extract 1500 calories from a meal, and you 1800 calories from the same meal), but I don't think others are comfortable with that idea. And if it varies across individuals, why is it impossible to vary with one individual over time, or change drastically in a short period of time? Can the physiology of your body change to (for example) start extracting more calories from food than it normally does? It doesn't seem like that crazy of an idea to me, and if it can do this (as anecdotal evidence suggests), then it makes weight loss strategies much more complicated, and it makes the simple calculations no longer work under all scenarios. This doesn't seem like a terribly controversial idea to me.
  - mikekchar 11y ago
    You can't extract more calories from food than their are. Calories are measured by actually incinerating the food and measuring how much heat it gives off. That is literally how much energy there is. So if you eat 2000 calories of food energy, you can not (if you are obeying the laws of thermodynamics) gain more energy than that. You can only absorb less. Similarly, as I said in a message above, there is a lower limit for how much energy your body must burn in order to maintain body temperature. You will find if you look at the rate at which corpses lose heat to ambient temperature that it is very, very close to what is listed on those base metabolic rate charts. Again, I have to stress this: you can not burn less than that without decreasing your temperature and dying. It is a physical impossibility. There are obviously variations, of course, but they must (by physical necessity) be on the up side. So you can easily eat 3000 calories and not gain any fat, even though you don't exercise, if you have a thyroid problem, or if you have a digestive problem that causes food to shoot through you before you can process it. On the other hand, you can not (due to the laws of physics) eat less than the number of calories required to maintain body temperature and not lose weight. This is conservation of energy. And as I said, the minimum amount of energy required to maintain your temperature is very close to those base metabolic rate charts. Sure you can be off by 100 calories a day. You can't be off by 1000. It just isn't possible. So if you are in deficit for several hundred calories a day and you aren't losing weight it is necessarily because you have measured your exercise or diet incorrectly. As I stated several times, this usually occurs because companies outright lie about how many calories you can burn through exercise (and are often off by 1 or 2 binary orders of magnitude). It is also because people completely overlook high calorie foods, even if they are otherwise very careful.
leshow 11y ago
> You did a fairly decent job of discrediting your "the same thing will 'work' for everybody" statement. Did you even read his post? A caloric deficit will 'work' for everybody by definition.
- mistermann 11y ago
  A caloric deficit once achieved will work for everybody, but different people absorb calories differently - so, as was being discussed, the same thing (calories consumed per kg of body mass + exercise) will not work for everybody.
  - leshow 11y ago
    you keep harping on this 'absorbed calories' thing. and it's irrelevant to the discussion and not helping your argument. people have different caloric requirements doesn't mean that a some people magically can't turn body tissue into energy.