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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

#641

Post by csee »

uberduper wrote: post #609
csee wrote: post #399

Earlier quoted context omitted.

The article mentions a study that tracked energy expenditure of runners over many weeks, and found that the energy expenditure was much lower at the tail end of the experiment, suggesting the body gets accustomed to the activity somehow and burns less energy.

The study must have tracked non-runners, given the conclusion. If they were already runners and the conclusion is that they get accustomed to the activity, they'd already be accustomed and there'd be no tail end difference. So they most likely tested non-runners and had them start running. We get more efficient at physical exertion with practice. Better coordination of muscle groups. Finding a more efficient pace. Co…

This assumes that there isn't a spectrum of running intensity. In this case they were running 10s of kilometres every day during the study, an absurd distance. So they were likely experienced runners already who were engaging in this extreme competition and took it up to an abnormal intensity that they weren't used to.

Re: Scientist busts myths about how humans burn calories

#642

Post by recursive »

taeric wrote: post #128
anchochilis wrote: post #96

Earlier quoted context omitted.

Yeah, for a few years in my 20s I was bike commuting 24 miles/day and running 6-10 miles/day on top of that, with longer runs or hikes on the weekends. I was in the best shape of my life, felt great and ate whatever I wanted without thinking about it. BUT I was spending 4 hours per day exercising. Now I have a 6 week old baby and WFH... I manage a 30 minute Peloton a few times a week. Maybe. Even though I try to pay…

Some of that is just being in your twenties. :). Pretty sure just thinking of a hike lost weight back then.

I picked up biking in my 20s, and was slimmer than I was in my teens. That's with no intentional change to diet. No one will ever be able to convince me that you can't lose weight with exercise. When I was doing ~90 minutes of cardio a day, it was impossible not to notice.

Re: Scientist busts myths about how humans burn calories

#643

Post by tsimionescu »

achenatx wrote: post #600
tsimionescu wrote: post #324

Earlier quoted context omitted.

Based on your description, I will venture a guess that you are not obese / grossly overweight. There is good evidence from various studies that obese/overweight people are not typically able to achieve this - usually their craving for food is far too powerful to just control simply by falling into a routine; or, the body sometimes finds other ways to adjust (the lipostat model). This is really the problem with CICO -…

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 weeks) will gain weight as expected, but will naturally lose it back over the next period without explicit effort.

This has generally been treated as a lifestyle issue, but another possibility gaining traction is that "obesity" is a disease in itself, one that tricks your organism is seeking to maintain excessive weight, by impacting your appetite, BMR, exercise habits etc; this will of course usually make people suffering from "obesity" (for lack of a better name) over-weight, but the weight can be controlled without curing the disease. Basically losing weight doesn't cure your "obesity", just like when you suffer of diabetes, controlling your diet keeps you healthy without curing your diabetes.

The possible causes of this "obesity" disease could well be diet related, and definitely refined sugars seem to be at least a major culprit.

Re: Scientist busts myths about how humans burn calories

#644

Post by pessimizer »

mrleinad wrote: post #594
artdigital wrote: post #378

Earlier quoted context omitted.

My advise: (as someone who does a lot of working out and calorie control) Write down what you eat for a while and its calories. Weigh yourself daily as well and write that down too. If after a week your weight went up: Your calories are above your TDEE. If it went down: Your calories are under your TDEE. And that's basically it, once you know what your TDEE is, eat under it to create a caloric deficit and you will lo…

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)

If you eat a lot of similar stuff, after looking up things periodically over time you'll get to be able to ballpark calorie counts. Calories aren't really hidden that well.

Re: Scientist busts myths about how humans burn calories

#645

Post by wildmanx »

tom-thistime wrote: post #581
wildmanx wrote: post #572

Irony. A linked article describing a scientist trying to rigorously find out how weight changes and energy expenditure and diet are connected, revealing the little we do know and the vast sea of what we do not know. The discussion here: full of anecdotes and bro science berating one another "that's not how it works, it works like this", "I personally do this-and-that", "you just have to x-y-z, it's that simple".

Yes. And no. Bro science is more or less useless. But the article isn't super useful either. Calories burned are "adjusted for nonfat body mass." Adjusted how? Fat stores energy. Food adds energy. Exercise uses energy. Those aren't "myths." The article (not talking about the scientist) is very difficult to understand, but it seems to come down on the "myth" side of that dilemma. Mostly. Kind of.

It's a popular science article. What did you expect? If you want all the details, read the actual published studies. For the general public, scientists need to simplify things.

Re: Scientist busts myths about how humans burn calories

#646

Post by wildmanx »

tom-thistime wrote: post #621
koheripbal wrote: post #602

Earlier quoted context omitted.

When you do the math, your body turns out to be extremely efficient. Two full hours of very hard exercise burns the equivalent of one average sized lunch meal. Skipping meals/cutting calories is, by far, the easiest way to lose weight.

Let's get specific. Maybe your suggestion might be a cataclysmic -1000 calories per day, either by (a) skipping a large lunch completely and not changing exercise, or (b) by doing those two hours of hard exercise and not changing diet. That person will tend to lose around two pounds a week either way over the long term. (Of course I don't really know what numbers you have in mind.) But losing two pounds a week is ins…

> So let's look at safer, more normal behavior. Call it -300 calories per day: either cutting diet by a medium order of fries each day (and keeping exercise fixed) or doing 40 minutes of moderate exercise (and keeping diet fixed).

That's not how it works though, and the article we are discussing here is hinting at that. The mechanisms are very complex. Going for a run for 40 min that "burns" 300 calories versus not going on that run won't create a calorie deficit of 300 calories. Because "everything else equal" is never going to happen.

There could be tons of effects happening to offset this. Eating more? Eating subtly different things? Eating it in different ways that impact nutrient uptake? More efficient nutrient uptake even when eating the same things in the same way at the same time? Changing patterns of movement that now use less energy? Change in overall metabolism (body temperature, body movements, ...)? Less stress, saving energy? ...? This is a very complex topic and "calories in versus calories out" is just not cutting it. And that's what the article is about. It's an approximation, but a so coarse one that it's barely usable for anything.

Re: Scientist busts myths about how humans burn calories

#647

Post by rory »

foxfluff wrote: post #417
emodendroket wrote: post #177

Earlier quoted context omitted.

I know this isn't rigorous but it definitely matches up with my personal experience -- I'll be hungrier, often ravenously so, after strenuous activity.

The activity makes a big difference for me though. Running for example tends to not have a major impact on appetite.. sometimes I feel like it actually lowers my desire to eat. That's based on relatively short runs though (45-90 mins of activity). I don't know how I'd feel after a marathon. If I ride a bike for 3 hours, I feel like I could eat a horse.

This matches my experience. Swimming or biking makes me hungry. Running a reasonably long distance (say, 7+ miles) makes me a slightly nauseous and not hungry at all. Maybe it's because running causes more jostling and/or beats up non-muscle parts of the body more?

Re: Scientist busts myths about how humans burn calories

#648

Post by tom-thistime »

wildmanx wrote: post #645
tom-thistime wrote: post #581

Earlier quoted context omitted.

Yes. And no. Bro science is more or less useless. But the article isn't super useful either. Calories burned are "adjusted for nonfat body mass." Adjusted how? Fat stores energy. Food adds energy. Exercise uses energy. Those aren't "myths." The article (not talking about the scientist) is very difficult to understand, but it seems to come down on the "myth" side of that dilemma. Mostly. Kind of.

It's a popular science article. What did you expect? If you want all the details, read the actual published studies. For the general public, scientists need to simplify things.

I'd expect them not to call ordinary long-accepted facts "myths" without some kind of coherent explanation. That isn't simplification.

Re: Scientist busts myths about how humans burn calories

#649

Post by nradov »

aixi wrote: post #380
throwaway09223 wrote: post #206

Earlier quoted context omitted.

I'm a 40 year old guy who's been sitting behind a desk writing software for two decades. I was in good shape in my 20s but haven't exercised significantly in a very long time. It took me about three months to get up to that speed, cycling every other day. I started out doing 10 miles, at 10mph. Three months isn't all that long for an exercise program.

same here, I'm in my late 20s and was generally unhealthy because of the pandemic, and I burn 630-700 calories per 30 minutes worked out

That is unlikely. How are you measuring calorie burn? You're probably overestimating.

As a point of comparison, an average size man would have to run at a speed of at least 11 mph (18 km/h) in order to burn that many calories in 30 minutes. Not impossible, but well beyond what most of us can manage.

Re: Scientist busts myths about how humans burn calories

#650

Post by ajuc »

mrleinad wrote: post #594
artdigital wrote: post #378

Earlier quoted context omitted.

My advise: (as someone who does a lot of working out and calorie control) Write down what you eat for a while and its calories. Weigh yourself daily as well and write that down too. If after a week your weight went up: Your calories are above your TDEE. If it went down: Your calories are under your TDEE. And that's basically it, once you know what your TDEE is, eat under it to create a caloric deficit and you will lo…

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)

When you cook for yourself it's pretty easy. After a month you remember kcal per 100g for each common ingredient and the weight is on the box or on the receipt anyway.
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