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Daily energy expenditure through the human life course

research.brighton.ac.uk

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Re: Daily energy expenditure through the human life course

#61

Post by crazygringo »

logicchains wrote: post #34

Muscle burns more energy than fat. As people age, their muscle mass declines without sufficient exercise, so we'd naturally expect the average person's metabolism to decline via this even if "metabolism per kg muscle" didn't change.

But on the other hand, adding either muscle or fat burns more energy period, and we watch the average person's weight gain somewhere between 10 and 20 pounds over the first half of adulthood.

So we could easily expect the average person's metabolism to increase as well, simply to support the extra body mass regardless of composition.

Balancing out the two effects can only really be determined through careful statistics, and is going to be extremely variable per-person.

Re: Daily energy expenditure through the human life course

#62

Post by paulpauper »

SoftTalker wrote: post #25
hotnfresh wrote: post #22

Earlier quoted context omitted.

Anecdata: I ate 3500-4000 calories a day of mostly junk in high school and college. I lifted weights some. I (barely) “had a six-pack”. No sports, only incidental cardio. Around age 21 or so, I decided to try to drop a couple pounds and make it a really cut six-pack. I ate a strict 1400 calorie diet (packaged food to make it easy, no cheating at all) for about three months. I started running a couple times a week. I’…

Teens are growing until early 20s that’s why they can and do eat so much. When you stop growing you enter into your adult metabolism. I started gaining weight/fat in my mid 20s and had to adjust my eating habits from what was normal in the preceding 8-10 years

but the article says it's gradual. gaining 20+ lbs in a year not gradual.

Re: Daily energy expenditure through the human life course

#63

Post by jakeinspace »

paulpauper wrote: post #43
logicchains wrote: post #34

Muscle burns more energy than fat. As people age, their muscle mass declines without sufficient exercise, so we'd naturally expect the average person's metabolism to decline via this even if "metabolism per kg muscle" didn't change.

muscle burns very little calories, and even pro bodybuilders who have lots of muscle quickly put on fat off-season when not dieting. I don't think this explains it.

It is essentially impossible to put on muscle at their size without also gaining fat, because they need to be in a large caloric surplus. During the off-season, pro bodybuilders are still training, they just increase their calorie intake significantly. Muscle does burn quite a few calories passively, it's just not nearly enough on a 260lb man to cover 6k-10k calorie intake.

Re: Daily energy expenditure through the human life course

#64

Post by constantly »

dp-hackernews wrote: post #47
logicchains wrote: post #34

Muscle burns more energy than fat. As people age, their muscle mass declines without sufficient exercise, so we'd naturally expect the average person's metabolism to decline via this even if "metabolism per kg muscle" didn't change.

"Even when you’re sleeping at night, the brain consumes roughly as much energy as it does during the day." https://www.brainfacts.org/brain-anatomy-and-function/anatom... Does this change over time also?

I wouldn’t trust a site called BrainFacts to be unbiased given the source.

Re: Daily energy expenditure through the human life course

#65

Post by paulpauper »

arpinum wrote: post #58
m3kw9 wrote: post #52

Earlier quoted context omitted.

A lot of skinny people have high metabolism, how do you explain that?

Fidgeting.

Then why can't someone just make an exercise program that replicates this fidgeting. How is fidgeting more potent than 10,000+ steps/day , which a lot of people do but still stay fat.

Re: Daily energy expenditure through the human life course

#66

Post by dp-hackernews »

jayGlow wrote: post #48
paulpauper wrote: post #43

Earlier quoted context omitted.

muscle burns very little calories, and even pro bodybuilders who have lots of muscle quickly put on fat off-season when not dieting. I don't think this explains it.

they put on fat because the body fat level they compete at is unsustainable for long periods of time. additionally gaining fat is unavoidable when trying to gain muscle past a certain point.

I would argue they are not "gaining" fat, rather they are "balancing" the amount of fat the body considers normative. Of course you can easily acquire more fat with an inappropriate diet consisting of too much sugar, but a healthy diet will see your body maintain the ratios that are optimal for your current requirements.

It never ceases to amaze me that we think that we know better, and yet the human body, as with other animals etc, have been around for quite some time now. Even if we had all the data from the past that we think is important now, we still wouldn't know better.

There was a post the other day regarding "The prosecutors fallacy" that might fit well with this sort of subject matter.

Re: Daily energy expenditure through the human life course

#67

Post by darkerside »

m3kw9 wrote: post #52
logicchains wrote: post #34

Muscle burns more energy than fat. As people age, their muscle mass declines without sufficient exercise, so we'd naturally expect the average person's metabolism to decline via this even if "metabolism per kg muscle" didn't change.

A lot of skinny people have high metabolism, how do you explain that?

Casual factor. Higher base metabolic rate means less energy available to build body mass.

Re: Daily energy expenditure through the human life course

#68

Post by smileysteve »

fortran77 wrote: post #21
smileysteve wrote: post #18

This doesn't seem to line up anecdotally; The first outlier I see is female health and PCOS, starting in mid 20s for women. The next outlier I see is insulin resistance and pre and diabetes based metabolism decline. From a hormone perspective, nose, ear, chin (femalr), and head hair seem to be going under significant change.

This is caused from eating too much, not a decline in “metabolism”

So, the combination of the research and my anecdotes - and your response seems to be

That by our early 20s our metabolism has already slowed (sugary food, alcohol, precipitous drop in activity)

Re: Daily energy expenditure through the human life course

#69

Post by logicchains »

m3kw9 wrote: post #52
logicchains wrote: post #34

Muscle burns more energy than fat. As people age, their muscle mass declines without sufficient exercise, so we'd naturally expect the average person's metabolism to decline via this even if "metabolism per kg muscle" didn't change.

A lot of skinny people have high metabolism, how do you explain that?

I'm not saying metabolism doesn't vary among individuals, I'm saying for a given individual, their overall metabolism could decrease as they age due to having less muscle mass even if their rate per kg muscle didn't change.

Re: Daily energy expenditure through the human life course

#70

Post by logicchains »

paulpauper wrote: post #43
logicchains wrote: post #34

Muscle burns more energy than fat. As people age, their muscle mass declines without sufficient exercise, so we'd naturally expect the average person's metabolism to decline via this even if "metabolism per kg muscle" didn't change.

muscle burns very little calories, and even pro bodybuilders who have lots of muscle quickly put on fat off-season when not dieting. I don't think this explains it.

Muscle tissue burns 7-10 calories per pound per day. This means someone who gains 100 pounds of muscle (e.g. from 150 lbs untrained to a 250 lbs bodybuilder) would increase their metabolism by 700-1000 calories, almost a 50% increase in the average daily male calorie requirements of around 2000 calories.
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