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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

#291

Post by Terr_ »

ericmcer wrote: post #253

I feel like this is already known? I watched some anime Netflix years ago where the main character played a board game. Eating candy to account for the energy expenditure of the mentally taxing game was in the script. I read an article about Magnus Carlsen exercising and eating a strict diet so he could cope with the energy expenditure of high level chess for long periods. It's weird to see it now framed as like a re…

> Eating candy to account for the energy expenditure of the mentally taxing game

That reminds me of someone who made a fanny-pack that tracks your walk/run progress and dispenses M&Ms.

https://hackaday.com/2021/07/30/step-n-snack-fanny-pack-moti...

Re: Scientist busts myths about how humans burn calories

#292

Post by makeitdouble »

dahart wrote: post #179
thisisonthetest wrote: post #162

Earlier quoted context omitted.

CICO is almost as pernicious and ubiquitous. It really grinds my gears when people try to use “intuition” to understand something super complex with no data at all. People talk about “metabolism” the same way. Say the word “toxins” around me and I will fight you in the streets.

Except we have literal truckloads of data on calories and metabolism. Like a lot of human physiology, these things come with Normal (Gaussian) distributions in the human population. There are averages and deviations we can talk about, without having to understanding anything about the inner workings of the human body, right? I couldn’t agree more that CICO is a super blunt instrument, but it actually does work, becau…

> truckloads of data on calories and metabolism

We have, but most of it seriously flawed because of many issues.

For instance this pretty serious study on diets (http://www.dishlab.org/pubs/MannTomiyamaAmPsy2007.pdf) had to rely on BMI for segmenting the subjects because the whole field had standardized on BMI. Yet we know for decades that BMI based segmentation is meaningless, BMI itself being a clunky relic of the past. Then you can come down on the subject of the studies, repeatability, no possible control group most of the time etc.

We can say that's the best we can do, but we should also accept it's far from being reliable info most of the time.

> it actually does work

well, it doesn't work or not, it's just a concept, an observation like a law of physics. It's like saying gravity works, that's not the info you'd give people having difficulties to build a self balancing robot.

Re: Scientist busts myths about how humans burn calories

#294

Post by ehnto »

bagacrap wrote: post #239
PaulDavisThe1st wrote: post #84

Earlier quoted context omitted.

Cycling is roughly 5x more efficient than running/walking for similar effort. Thinking you will lose much weight by cycling is generally mistaken, unless you plan to cycle very long distances or are extremely obese already and do very little existing exercise (and this is discounting most of what TFA is saying too).

wouldn't efficiency correlate to effort? pretty sure the "effort" is the feeling of burning calories. If an elite athlete can run for an hour and burn 2000 calories in that time, they will beat a less elite athlete who can run for 1900 calories in an hour, all else equal. Put them on bicycles or a rower and they'll be able to burn the exact same number of calories (assuming sufficient training in the target exercise…

I'm not sure it makes sense to look at it that way either. What if it takes you 100 calories to move 100 meters but your competitor only takes 80 calories to move 100 meters?

Re: Scientist busts myths about how humans burn calories

#295

Post by mrcode007 »

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…

I think the debate has been settled a long time ago:

https://www.bmj.com/content/349/bmj.g7257

Re: Scientist busts myths about how humans burn calories

#296

Post by zmmmmm »

lordnacho wrote: post #261
soperj wrote: post #254

Earlier quoted context omitted.

It's not true though. If you exercise enough you will be in a calorie deficit regardless of what you eat. I knew rowers that couldn't keep weight on during the season no matter what they ate, and they ate a lot. The exercise is what is causing the calorie deficit, not watching what they ate.

But you can eat the calories you spend in just a few minutes. If you have a pile of Mars bars, that will supply enough energy to compensate an hour on the treadmill. Might not be the typical thing an athlete eats, but it certainly keeps the weight on a lot of people.

But that goes to the other part of the fallacy, because even if you eat a pile of 10 Mars bars, a large amount of that will just get excreted. Meanwhile you'll start to feel physically sick and probably your body will then reject food for a while. CICO does more harm than good in IMHO because you're talking about a complex system.

Re: Scientist busts myths about how humans burn calories

#297

Post by lordnacho »

dahart wrote: post #4

> “You can’t exercise your way out of obesity,” […] “you can’t outrun a bad diet.” While this article is being a bit dramatic and possibly understating the impact of exercise slightly, I feel a little dumb that I didn’t know this earlier. It took me several decades too long to understand the obvious, that exercise is for building strength, and losing weight happens by eating less. I tried for way too many years to ex…

Just a simple scan of some foods and some exercise calorie amounts and times should show it.

Reasonably tiring exercise on a bike could burn 10 Cal per minute, so maybe 600 an hour. But swallowing a few packs of crisps or a few chocolate bars could fill that right back up in a couple of minutes. If you were speed eating you could swallow it in under a minute.

Think about if your weight is steady, how long you spend eating and how long you spend using energy. It can easily be the case that you spent all your calories in 23.5 hours and were eating for just half an hour.

The time ratio is so lopsided it's hard to come up with a plan where exercise carries most of the weight loss vs just eating less.

If you think of your energy use as base rate plus exercise rate, because your base rate is sustained for the whole day you'd have to exercise like crazy for a long time to make up any difference to what you eat.

Re: Scientist busts myths about how humans burn calories

#298

Post by sizzle »

bsder wrote: post #210
timr wrote: post #137

Earlier quoted context omitted.

I have also done almost exactly this process, and it worked for years to regulate my weight. But then I hit a plateau (a high plateau, not a low one) where I was unable to drop weight no matter how low I cut my calories. I started at a range that I knew had worked in the past, and lowered it over the course of weeks, well past the point where I was miserable. I even tried more complicated things, like varying my inta…

> But then I hit a plateau (a high plateau, not a low one) where I was unable to drop weight no matter how low I cut my calories. Fat cells "remember" their metabolic environment when they were created--ie. they "remember" your weight and fight you when you try to reduce it. It's one of the problems with dieting to large weight losses. It is somewhere around 3 years for a fat cell to die off and be replaced. You prob…

I thought you never lose fat cells, they only shrink? Got a citation for that assertion?

Re: Scientist busts myths about how humans burn calories

#299

Post by xurukefi »

"You can’t outrun a bad diet" seems to be the party line among fitness people these days. Anecdotally speaking that's not really true for a lot of people. I run > 100km/week pretty much all year round (most of it on extremely hillly trails) and despite my bad diet consisting mainly of pancakes, white bread, nutella, pizza, fries and burgers, I am not overweight with 78kg at 190cm. Before I picked up running I was moderately overweight. If I can't run for a prolonged period of time, then I start gaining weight again. I've met plenty of people who run similar mileage and many of them also have pretty bad dietary habits but none of them are oeverweight. Note that I'm not saying that this is healthy (it clearly isn't).

However, I still think that there is a lot of truth to the "you can't outrun a bad diet" statement. A lot of people who occasionally go for a run are likely to overestimate their energy expenditure and feel like they have to eat a cow to compensate. I think, however, that the statement becomes less and less true the more excessive the exercise gets. If you burn thousands of calories day in day out with exercise it seems to become harder to overcompensate this every time with excess food intake.

I think the bigger issue with exercise is a mental one. Weight loss seems to be a pretty bad motivation for exercising. Most people I know who picked up running for the sole purpose of losing weight eventually gave up or they are stuck with their 5km weekend park run, which, of course, is rather pointless for their objective. 100% of the avid runners I know (including myself) don't care about their weight. I could probably lose more weight (or improve my long term health) if I changed my diet, but it's simply something that I'm not interested in. I run because it's fun and a somewhat low body weight seems to be a by-product of that.

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