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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

#211

Post by qingcharles »

tails4e wrote: post #123

I've always been curious about my own metabolism. When I was a teenaeger / in university I ate pretty badly. Chocolate bars every day after lunch, loads of carbs, not to mention alcohol, etc etc. I was rail thin. I once got a body fat assesment when I joined a gym (I did no exercise at all and this was a brief attempt to get buff) and the person doing the test was shocked and couldn't pinch anything to measure. I had…

I wonder about the same thing. I was a fat kid, but my best friend was so skinny. We would walk down town and he would stop several times to stuff chocolate bars in his mouth, and then buy two McDonald's meals. I would do none of this and our physical exercise was the same.

Then we went away to University and in his mid-20s the poor guy suddenly, almost overnight, put on a ton of weight.

Re: Daily energy expenditure through the human life course

#212

Post by nradov »

jeffbee wrote: post #159
missedthecue wrote: post #155

Earlier quoted context omitted.

Humblebrag? Almost 100% of humans are incapable of doing a four hour 100km bike ride without a lot of prep and training. Nevermind doing this daily.

While true, the energy expense doesn't really scale with speed, so if a couch potato got up and decided to do 100k in, say, 8 hours, that's around the same amount of energy. NB nobody would be able to do this without ingesting a substantial amount of food during. If you didn't start eating hourly after about 1-2 hours in, you'll "bonk" or run out of glycogen.

It really depends on how fat adapted your metabolism is. When untrained people exert themselves their muscles tend to produce most energy from glucose and very little from fat. By doing a lot of zone 1-2 training you can gradually shift your metabolism to rely more on fat, at least at lower effort levels where you're not limited by oxygen. This allows you to go longer than 2 hours without bonking.

Re: Daily energy expenditure through the human life course

#213

Post by nradov »

paulpauper wrote: post #188
missedthecue wrote: post #126

Earlier quoted context omitted.

That's also completely canceled out by enjoying a single 32oz soda. Walking a lot and having a bad diet rarely even each other out. And it's so easy to cancel it out I don't think most people realize. A brisk 2km walk burns less calories than are consumed when eating two regular Oreos.

It is even worse than that. The conversion rate of activity to net calorie loss is not 1 to 1 . It can be zero or even negative, at least based on my own experience and other people. You see people on Reddit subs do 10k steps and tons of walking, hardly lose any weight. It's all about not overeating.

Walking is great for many reasons, but 10K steps isn't much. It would be silly to expect much weight loss from that. And most people significantly understand their caloric intake.

Re: Daily energy expenditure through the human life course

#214

Post by nradov »

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?

How do you know those skinny people actually have high metabolism? Have they quantified it with a resting metabolic rate test?

Re: Daily energy expenditure through the human life course

#215

Post by alex-korr »

nradov wrote: post #142
blipvert wrote: post #95

Earlier quoted context omitted.

That is an insane amount of training - big lifestyle changes! I increased my calorific needs by 1000 a day by doing a 10K run (1hr) before breakfast. Still a 160lb weakling :)

That seems high. Someone your weight would generally only burn about 750 kcal on that workout.

750 kcals is insanely high for a 10k training run. If you hold your HR to Z2, 620-640 kcals would be my ballpark expectation.

Re: Daily energy expenditure through the human life course

#216

Post by naijaboiler »

Jenda_ wrote: post #203
lkbm wrote: post #202

Earlier quoted context omitted.

Okay, so just to be clear: the OP is describing a phenomenon that is extremely widely reported, and is doing so in discussion thread about study that also reports finding this phenomenon , and your claim is that the simplest explanation is that OP is misremembering, and the research is just wrong? Do you have any evidence for this bizarre dismissal?

I don't understand where does the excess basal energy expenditure go. Do persons like the OP when <25 y.o. produce significantly more heat (e.g. wearing only t-shirt and shorts even in winter, and "dying" in the summer)? Does the skinnier body mean way bigger heat losses, even when compared to bigger surface area after getting fat (i.e., way higher surface temperature)? (presumably yes, but to this extent?) The artic…

one possible explanation for me, calories ingested != caloric intake. I ate more, pooped more. So even if my body's metabolic efficiency didn't change, perhaps my ability to extract calories from what i ate changed.

Sitting down and eating 6 plates of pasta at Fazolis all-you-can-eat for $4 (or $6) + 12 breadsticks every wednesday evening, is not something you can misremember. i was a broke student, and it was most economic meal i used to have. Working at mcdonalds and eating double quarter pounder meal + extra quarter pounder + shake is not something i can misremember. clearing a tub (not a pint) of ice-cream at a sitting is not something i can misremember. setting timer to dliberately eat 6 times a day all summer in order to forcefully gain wait, is not something i misremember. emptying an entire box of cereal in a sitting is not something i misremember. Eating 25 big wings to the bone at a sitting is not something i misremember. And i was all of 130lbs max. It really is insulting to suggest that the likely explanation is that I am misremembering.

In my 40s now, eating a lot is day like today when all I ate was jamaican takeout that i ate most of it. and that's on the high end of what i usually eat. i strictly drink water and black coffee, nothing else. my entire 20s was pop and juice. thats easily another 400 calories daily. I am 150lbs now.

Re: Daily energy expenditure through the human life course

#217

Post by ashconnor »

naijaboiler wrote: post #147
MichaelDickens wrote: post #130

Earlier quoted context omitted.

In addition to activity levels, you probably just weren't eating that much food. It was similar for me when I was a teenager: some days I would binge on a ton of junk food, but other days I would forget to eat breakfast, and the latter happened often enough that I stayed skinny.

No I legit ate way much much more in my 20s. I'm not misremembering. I ate more

I was rake thin until I started lifting weights with a buddy of mine at university. However it wasn't until I started GOMAD that I noticed any muscle and weight gain.

Before that I was eating crap. Lots of things that I that were high in calories but not enough of them throughout the day to exceed my metabolism or get close to the amount of protein I needed.

I think if you could go back in time and count the calories you probably were eating as much as you think.

Re: Daily energy expenditure through the human life course

#218

Post by IsoldesKnight »

glouwbug wrote: post #209
_Algernon_ wrote: post #141

Earlier quoted context omitted.

This. Plenty of times I've been to lazy to make dinner and ate 200g of chocolate and a coke in a single sitting.

The American dream

Pretty sure if it was the American dream, it would be 7oz of chocolate.

Re: Daily energy expenditure through the human life course

#219

Post by djtango »

tails4e wrote: post #123

I've always been curious about my own metabolism. When I was a teenaeger / in university I ate pretty badly. Chocolate bars every day after lunch, loads of carbs, not to mention alcohol, etc etc. I was rail thin. I once got a body fat assesment when I joined a gym (I did no exercise at all and this was a brief attempt to get buff) and the person doing the test was shocked and couldn't pinch anything to measure. I had…

How much "passive activity" were we doing back in the day?

So as a teenager, I was carrying 5-10kg of books and walking back and forth between classes every 40 mins.

As an undergrad I was travelling across campus multiple times a day, spent hours on my feet in labs, did multiple heavy grocery shuttles and also spent a lot of time partying.

In my first job, I was still getting up 5-6 times a day for meetings and had a decent walk/cycle built into the commute. but in my first remote job, I could be sat in the same spot for 8-10 hours without moving. And because I wasn't drinking water I wouldn't need to go to the bathroom... /facepalm I'd also be so engrossed that sometimes I'd forget to turn on the lights...

So even though I do more than an hour of intense exercise a day, my activity outside of those exercise hours has cratered from when I was a teenager and was constantly running around.

Re: Daily energy expenditure through the human life course

#220

Post by scythe »

lkbm wrote: post #202
goostavos wrote: post #199

Earlier quoted context omitted.

>I'm not misremembering It's the easiest explanation. As a gym bro that regularly cycles weight, it's is remarkably easy over/under estimate intake just going off recollection. I always think I'm dialed in until I write things down (I'm almost always eating way fewer calories than I think).

Okay, so just to be clear: the OP is describing a phenomenon that is extremely widely reported, and is doing so in discussion thread about study that also reports finding this phenomenon , and your claim is that the simplest explanation is that OP is misremembering, and the research is just wrong? Do you have any evidence for this bizarre dismissal?

The study says that TDEE is generally constant from 20 to 60. Multiple studies have shown that on average people do a terrible job of estimating their food intake ([1], [2] for example), especially when they aren't actively monitoring it. Meanwhile the person you're talking about (who isn't properly "OP") is claiming that they ate more in their 20s than they do today without corresponding health effects. This is not consistent with TFA nor with previous research.

1: https://www.nejm.org/doi/full/10.1056/nejm199212313272701

2: https://www.tandfonline.com/doi/abs/10.1080/08870446.2019.16...

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