And, though it is my understanding that the ’3500 kcals = 1lb of body fat’ is a less-than-precise rule of thumb that fails to account for many variables in regard to weight loss, it stills stand to reason that a couple hundred kcals per day would add up to something substantial over the course of, say, even a few years.
So, it seems you could have persons A and B—each eating and exercising at exactly the same level—end up tens of pounds apart from one another in body weight over a relatively short span of years. Over decades, you could see one person end up fit, and the other very obese.
I’ve noticed two broad opposing views on body weight.
View 1: Metabolism differences aren’t that big a deal. Diet and exercise will make up the differences with relative ease. (Seems to be the tone of the Examine.com article linked above.)
View 2: Metabolism differences are significant and account for most of the differences in regard to individual body weight.
So, which is it?
It seems to me metabolic differences between individuals are very significant. If person A uses an average of 200 kcal per day less than person B due to differences in RMR, that means person A must expend millions and millions more calories during their lifetime in order to maintain the same body weight. Person A would need to devote an immense amount of combined time towards exercise and/or will power towards eating healthy just in order to “keep up”.
Dave Asprey managed to have lose weight at >4000 calories per day.
A QS friend I know replicated this and found that adding 1000 calories per day in butter for a month didn’t raise his weight either. My own attemts to raise my weight by throwing ~800kcal of maltrodextrin per day into my tea also didn’t raise my weight.
Metabolism is not only important between individuals but also changes day to day due to different hormones.
Both are important, some more so for some people than others. I and members of my family are lucky enough to lose weight rapidly with food restriction and exercise; many other people not so much. WHAT is eaten rather than its sheer energy content can also make a big difference.
There seem to exist non-negligible differences in individual RMR.
And, though it is my understanding that the ’3500 kcals = 1lb of body fat’ is a less-than-precise rule of thumb that fails to account for many variables in regard to weight loss, it stills stand to reason that a couple hundred kcals per day would add up to something substantial over the course of, say, even a few years.
So, it seems you could have persons A and B—each eating and exercising at exactly the same level—end up tens of pounds apart from one another in body weight over a relatively short span of years. Over decades, you could see one person end up fit, and the other very obese.
I’ve noticed two broad opposing views on body weight.
View 1: Metabolism differences aren’t that big a deal. Diet and exercise will make up the differences with relative ease. (Seems to be the tone of the Examine.com article linked above.)
View 2: Metabolism differences are significant and account for most of the differences in regard to individual body weight.
So, which is it?
It seems to me metabolic differences between individuals are very significant. If person A uses an average of 200 kcal per day less than person B due to differences in RMR, that means person A must expend millions and millions more calories during their lifetime in order to maintain the same body weight. Person A would need to devote an immense amount of combined time towards exercise and/or will power towards eating healthy just in order to “keep up”.
Dave Asprey managed to have lose weight at >4000 calories per day. A QS friend I know replicated this and found that adding 1000 calories per day in butter for a month didn’t raise his weight either. My own attemts to raise my weight by throwing ~800kcal of maltrodextrin per day into my tea also didn’t raise my weight.
Metabolism is not only important between individuals but also changes day to day due to different hormones.
Both are important, some more so for some people than others. I and members of my family are lucky enough to lose weight rapidly with food restriction and exercise; many other people not so much. WHAT is eaten rather than its sheer energy content can also make a big difference.
Why can’t anything in biology ever be simple...