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Scientist busts myths about how humans burn calories

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Re: Scientist busts myths about how humans burn calories

#501

Post by nelgaard »

deepnotderp wrote: post #282

The conclusion is almost certainly wrong: 1. From a simple sniff test, if this were true, then athletes wouldn't need a lot of calories. This obviously isn't true, eg Phelps eats 8-11K calories a day. I personally eat around 3.5K calories a day. If exercise didn't impact caloric burn I assure you I'd be a lot fatter... 2. The only plausible mechanisms for why exercise wouldn't result in more overall caloric burn is t…

Yes, those marathon runners mentioned might reduce their TEE from 6200 to 4900 kcal/day. But that is still way more than most office workers eat.

And if you check the article:

https://www.science.org/doi/10.1126/sciadv.aaw0341# == The reduction in TEE among RAUSA subjects can be partly attributed to marginally reduced body mass and daily mileage (table S3). Still, even after accounting for these changes, Week 20 TEE was 596 kcal/day lower (range, 400 to 923 kcal/day) than expected ==

So they did loose weight during the marathons and the metabolic compensation is less than half of what you would think reading the original article.

== ... The magnitude of metabolic response in RAUSA athletes (~600 kcal/day, ~20% TEE) is similar to the degree of adaptation reconstructed for the most physically active subjects in a recent cross-sectional study (17) and may reflect humans’ maximal capacity for metabolic compensation. ==

So if 20% percent is the maximum, it means that if you try to outrun your diet, you might have to eventually exercise 25% more. Except by then you will probably have more muscle mass that will burn more calories even when not exercising. And you will be able to exercise more in less time.

Suddenly it does not look so hopeless.

Re: Scientist busts myths about how humans burn calories

#502

Post by e12e »

skohan wrote: post #381
csee wrote: post #320

Earlier quoted context omitted.

Well that's what the article says. The Hazda who walk 8-12 km a day burn the less calories as an average American (or the same after adjusting for body weight). Also that Phelps thing is highly questionable. He says he "probably" burns 8-10k, not 12k. Not the type of statement you want to rely on to dismiss all this work.

I just have a hard time believing it to be true that no amount of exercise will increase the overall caloric expenditure. For example, I've done a few multi-week bike tours, and we ate an enormous amount of mostly pasta every day, and managed to peel off a few pounds each by the end of it.

It's strange. Go out in freezing weather and stand still;you'll get cold. Move about and you get warm. I find it unlikely that you can heat up without energy?

Re: Scientist busts myths about how humans burn calories

#503

Post by tlamponi »

irthomasthomas wrote: post #481
me_me_me wrote: post #472

Earlier quoted context omitted.

I don't get it, how is that a myth or controversial. Cutting empty calories is the easiest to remove calories from daily total. Exercise further decreases the ratio of calories in calories out. Bottom line is: calories in - calories out. There are caveats there for sure, like increasing muscle mass increases idle caloric burn. Different types of food have different effect promoting or impeding metabolism.

calories in - calories out was debunked a while ago. Different types of food and diet cause different degrees of weight gain or loss. For an extreme example compare 100 calories of glucose to 100 calories of fibre, both are types of sugar. The fibre contains an extra electron that acts like a shell, and the body has to expend energy breaking that bond to make it digestible. So most fibre passes through you without af…

> calories in - calories out was debunked a while ago.

Not really, it's just that calories-in is worst-case that's what's on the foods box, you cannot magically produce more energy but it's well known that not everything can be processed by the metabolism with the same efficiency.

So with extremes like your example the difference is naturally huge, but that doesn't matter in practice if one balances their consumption just somewhat it averages out and approaches something between upper (100%) and lower (0%) of efficiency, and in reality it rather close to the upper bound (averaged) as our metabolisms are quite efficient with the food most humans actually put into them.

Your glycemic index rule holds does not violate the calories in calories out rule, it's just more precise regarding the actual upper bound.

Re: Scientist busts myths about how humans burn calories

#506

Post by [deleted] »

rdiddly wrote: post #312

Last thing I saw was "The son of two high school English teachers, Pontzer grew up on 40 hectares of woods in the Appalachian bla bla bla..." You know that sentence. So many articles have that sentence. The one where it veers off course to talk about the (usually uninteresting) person who found the thing the article is ostensibly and nominally about. Am I alone in being perfectly happy reading about science for the d…

[deleted]

Re: Scientist busts myths about how humans burn calories

#507

Post by cataphract »

rdiddly wrote: post #312

Last thing I saw was "The son of two high school English teachers, Pontzer grew up on 40 hectares of woods in the Appalachian bla bla bla..." You know that sentence. So many articles have that sentence. The one where it veers off course to talk about the (usually uninteresting) person who found the thing the article is ostensibly and nominally about. Am I alone in being perfectly happy reading about science for the d…

I just skipped over that part...

Re: Scientist busts myths about how humans burn calories

#508

Post by irthomasthomas »

tlamponi wrote: post #503
irthomasthomas wrote: post #481

Earlier quoted context omitted.

calories in - calories out was debunked a while ago. Different types of food and diet cause different degrees of weight gain or loss. For an extreme example compare 100 calories of glucose to 100 calories of fibre, both are types of sugar. The fibre contains an extra electron that acts like a shell, and the body has to expend energy breaking that bond to make it digestible. So most fibre passes through you without af…

> calories in - calories out was debunked a while ago. Not really, it's just that calories-in is worst-case that's what's on the foods box, you cannot magically produce more energy but it's well known that not everything can be processed by the metabolism with the same efficiency. So with extremes like your example the difference is naturally huge, but that doesn't matter in practice if one balances their consumption…

Not really. E.g. look at my second example, cold potatoes vs hot potatoes. Same calories, same exact ingredients, but hot potatoes are significantly worse than cold potatoes.

I dont have the link to hand, but there is a GL database maintained by Harvard, I think, that demonstrates this. I will look it up later for you.

Re: Scientist busts myths about how humans burn calories

#509

Post by bluecalm »

lostmsu wrote: post #238
it_does_follow wrote: post #204

Earlier quoted context omitted.

If you train for endurance sports you'll definitely lose weight without much attention to your diet. For example, with marathon training, once you start to hit the 6 plus mile your daily run eats up over 1,000 calories. Near the end of your training your long run days become over 2,000 calories, and even your easy runs becomes 1000+. That's essentially an entire extra meal, and you're running 5-6 days a week. If you'…

This would be nice if 1hr+ a day would not be 5% of your conscious life.

Most people watch tv for 4-5 hours per day and it's far from the only time waster out there.

Something went wrong when very moderate volume of exercise (1 hour per day) is seen as a huge time commitment.

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