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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

#661

Post by nradov »

throwaway09223 wrote: post #577
nradov wrote: post #563

Earlier quoted context omitted.

Color me skeptical. In order to burn 1000 kcal in 60 minutes a cyclist would have to sustain a power output of about 280 W. Do you have a calibrated power meter, or are you going by the "vanity" calories displayed by most stationary bikes? There are certainly plenty of trained cyclists who can maintain that power output, but I've never seen anyone reach that level after only 3 months. If you really did that then you'…

I don't know, actually. I'll check it out later today. I do know my heart rate is around 150-160 throughout. I did a lot of cycling in my 20s and while I'm at least a decade out of shape I'm sure I'm relying a lot on past training.

High aerobic fitness evaporates pretty quickly. The training you did a decade ago will not carry over to today. However, there are a few genetic outliers who can quickly build up a high level of fitness with just a short training program. You could be one of them, but it's more likely you're just getting bad data.

Absolute heart rate doesn't tell us much about calorie consumption because there's a huge variation between individuals. If we know the athlete's size, sex, and threshold heart rate then we can start to make some kind of estimate. But to get an accurate number it really takes a properly calibrated power meter (or more complex lab tests involving exhaled gas measurement).

Re: Scientist busts myths about how humans burn calories

#662

Post by yurishimo »

achenatx wrote: post #596
Moru wrote: post #232

Earlier quoted context omitted.

I have no apetite at all after biking for two hours. However, if I drink any diet soda or piece of candy with sweetener, I will be ravenously hungry in 10 minutes. Has always been like this so I stay away from that stuff. My exercise is a game called Turf. Mostly played in Sweden where there are a lot of zones close by. I bike quite relaxed for 1-4 minuts and stand still for 20 seconds in the zone, then repeat until…

100% this for me. I do intermittent fasting and my first meal is around 2pm. I do brazilian jiu jitsu around 6-9 and skip dinner. When I come home Im not hungry at all for at least an hour. Ill get a little hungry and if I eat or drink anything, the floodgates open and I cant stop eating. It is better to go to sleep a little hungry. I try to have a 500 calorie deficit. If I have more than about 500 (say 1000) Im fine…

Oof this was me yesterday. Ate one large meal and snack between 2pm and 5pm because I had a work event in the evening. Got home around 9:30pm and really wanted to eat something and I almost did.

Drank a few cans of seltzer and wound up staying up doing emails and chores until 2am. Woke up at 9am today and I'm feeling a bit hungry at 11:20am, but even if I eat something now, it will be a net negative compared to what I would have eaten last night.

Re: Scientist busts myths about how humans burn calories

#663

Post by deepnotderp »

csee wrote: post #335
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…

1. Phelps seems to be guessing: "Maybe eight to ten thousand calories per day," he writes... Also, the research shows there is extreme variation in people's resting BMR (perhaps due to large variation in height, body weight, stress levels, etc), so you eating 3500 calories isn't decisive against the thesis of this article. 2. That is exactly his hypothesis, and he has produced evidence for this hypothesis in a recent…

1. I used to eat less calories and exercise less and was fat. Also for elite athletes TEE experiments have been fine.

2. Studies in nutrition science are a dime a dozen. Like in psychology, you should apply common sense to interpret the results. In this case, the implication is that the Hunter gatherer lifestyle is a chronically tired lifestyle for human bodies.

Re: Scientist busts myths about how humans burn calories

#664

Post by brippalcharrid »

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.

It's time that you can use for important things like meditation and consolidating your thoughts, as well as synthesising Vitamin D if it's close to noon and you're not especially far from the equator.

Re: Scientist busts myths about how humans burn calories

#665

Post by bradlys »

edanm wrote: post #547
xurukefi wrote: post #299

"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 mod…

I think I agree with your general point, and specifically agree that that statement is targeted as "mainstream advice", and might not be literally true. However, one point of disagreement: > 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.…

Yeah. I think the advice on diet is a good one for mainstream audiences. Giving nuance is difficult when people are looking for quick answers.

I had the same experience for a long time. People would see me eat Oreos, pizza, ice cream, pop tarts, etc. and they’d say, “how are you so incredibly thin if you eat all that garbage?” And I’d respond that I just eat less - I don’t eat a lot. And it was true. I’d eat garbage but I’d eat so little that I’d maintain an incredibly low weight. Now as I’m older and stress has gotten better - I’ve started eating more and gained weight due to it. It’s all due to the quantity/amount-of-calories.

Re: Scientist busts myths about how humans burn calories

#666

Post by nradov »

ajuc wrote: post #406
hgomersall wrote: post #392

Earlier quoted context omitted.

Yeah, I thought this. There's clearly an amount of exercise that will cause you to lose weight. An interesting question is whether your body prevents you from achieving that. Cycling was always interesting to me in this context because it seems easier to burn energy on a bike than other forms of exercise.

When cycling there's this "wall" you hit after a few hours. At least I do. After that it's much harder to keep pace or go uphill.

There's nothing special about cycling. You can deplete your glycogen stores and hit the wall with any aerobic activity. If you have a healthy metabolism and stay in heart rate zones 1-2 then you'll mostly burn fat stores and can cycle for many hours without hitting the wall. At higher zone 3+ efforts you'll need periodic carbohydrate supplements to keep going.

Re: Scientist busts myths about how humans burn calories

#667

Post by nu11ptr »

tsimionescu wrote: post #643
achenatx wrote: post #600

Earlier quoted context omitted.

the type of food definitely matters. Carbs somehow 1) dont fill you up 2) spike your appetite. When I do low carb I feel so much less hungry on lower calories. The deficit cant be too large, for me 500 is ok, but 1000 has me ravenous the next day. Lots of obese people easily lose 2 pounds/week but as you get closer to a healthy weight it gets harder. CICO was the first time I was able to actively lose weight in my en…

The general observation from most long-term clinical studies of obesity, as far as I understand, is that many types of diets work to reduce weight in the short term, but the weight almost invariably comes back after the intervention period ends (usually within 1 year or so after the initial weight loss). Conversely, people who are normal weight and are forced on a hyper-caloric diet for a limited time (say, a few wee…

Correct, temporary diets don't work. You have to change your lifestyle/diet permanently. This means after weight loss, you need to adhere to your new caloric intake baseline, which will be _lower_ than when you started. The more you lost, the lower it will be. This is hard, but not impossible to do. I can't speak for the obese because I was never there, but I was solidly overweight and proceeded to dump 40 lbs a decade ago, and never gained it back. Had I gone back to my pre loss diet it would have all come back.

NOTE: Before someone points it out, this is NOT incompatible with my parent comment. Going on a 500 cal/day cut and losing say 8 lbs will not lower your caloric baseline all that much, so temporary more or less works fine. If you use the same method to dump 40 lbs, you will need to readjust your baseline when done or you absolutely will gain it back as your caloric intake needs have been meaningfully reduced.

Re: Scientist busts myths about how humans burn calories

#668

Post by bavell »

jnsie wrote: post #623
mrleinad wrote: post #594

Earlier quoted context omitted.

I'd love to count calories. I'm just too lazy to measure and research everything I eat, and the alternative is to have only processed foods that are labeled. It's too bad that we can't just live on Soylent (the actual beverage, not the thing from the book)

I was very excited about Soylent years ago...until I tried it. I really disliked the flavor, so wouldn't have stuck with it regardless, but what really surprised me was how much I enjoy the act of sitting down and eating a meal. Soylent filled me up, but it never satiated me. Regardless of the time savings and predictability, I missed the act of eating, if that makes sense.

Makes total sense to me - we are creatures of habit and eating is one of our most sacred rituals. It's deeply rooted in our psychology so no surprise to me that one would miss the ritual even if satiated.

Re: Scientist busts myths about how humans burn calories

#669

Post by mantas »

ClumsyPilot wrote: post #628
mantas wrote: post #458

Earlier quoted context omitted.

> Your body burns incredibly more energy just "being there" than you burn moving about. Bullshit. My body goes through 1600-ish kcal on an idle day. If I go out on a 4h steady bicycle ride (= 100km), I go through 2000 kcal on ride alone. That’s much more than my body burns just being there.

"If I go out on a 4h steady bicycle ride (= 100km), I go through 2000 kcal on ride alone." What do you mean 'on that ride alone', are you doing more than 4 hours of excersise a day, every day? Because that's like 0.1% of the population, most can't even fit that in their diary, let alone have the stamina/etc. Average bloke goes to the gym for an hour couple times a week, at that level you calorie consumption is basica…

I used to ride amateur cycling races, then just do a nice amount of rides/runs.. Now I'm in situation where time outside the house is hard to manage. I try to cut the calories, but weight keeps growing and overall health decreasing. Looking forward to stabilising family circumstances to have time to head out enough...

From what I observed myself, cutting calories is very difficult and result is miniscule. Adding some cardio (2h/week? 5h/week?) helps so much more and allows more flexibility with food. Also cutting calories does not help to increased overall immunity. Cutting calories is hard on mood (as in, no sugar high and tasty foods are limited) yet exercising allows to keep tasty foods AND gives runner's high. Win-win...

As for tight schedule, I don't believe in gyms. People waste so much time driving to/from favourite/affordable gyms... Running right out home and doing body-weight exercises at home would be both more beneficial to one's health and cheaper.

P.S. I mean regular non-exercise day is 1600kcal. 4 hours ride would be 2000kcal. So exercise day would be ~ 3400. Obviously it long-ride is weekend affair. Then one or two run 10k runs or quick 1h ride (another 1k kcal each). So ideally it adds +500kcal/day. And a lot of cardiovascular health. Well, it was 2 years ago before kid was born... Now it has a loooooot of variation.

Re: Scientist busts myths about how humans burn calories

#670

Post by dahart »

makeitdouble wrote: post #292
dahart wrote: post #179

Earlier quoted context omitted.

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 th…

Those statements are technically true, but I’m not exactly sure what you’re trying to say. There’s nothing flawed about observational data that ignores the inner workings of the system, that’s how all of science works. Like you say, it’s physical observations. There’s nothing flawed about measuring wattage output of exercise while keeping food intake constant and noting that most humans lose weight under such conditions, or of keeping caloric output constant and increasing caloric input and noting that most humans gain weight.

> it doesn’t work or not, it’s just a concept, an observation like a law of physics.

It works as a tool for weight loss. It works for exactly the reason you state, because it’s primarily an observation of physics. The only way I gain mass is via my mouth, and the only way I lose mass is via energy expenditure. If I want to control mass, therefore, tracking and controlling my input and output is more or less guaranteed to work. For sure the input output responses might not be perfectly linear, but that’s expected and not a ‘flaw’. The weight response to calories also can’t be reversed or flat, due to physics, it must be highly correlated, right?

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