Scientist busts myths about how humans burn calories • Hacker News Board

Re: Scientist busts myths about how humans burn calories

#671

Post by coryfklein » Fri, Feb 18, 2022, 5:57 PM UTC

JeremyNT wrote: post #659

NoboruWataya wrote: post #616

Earlier quoted context omitted.

It's definitely true that eating less/healthier is the most important part of weight loss. However, perhaps because exercise played a big role in my own weight loss journey, I do feel like people go too far in dismissing it as a weight loss aid. First of all, while a 3k run isn't going to do much to burn off that slice of cake you had with lunch, if you transition from a generally inactive lifestyle to a generally ac…

My own anecdote: I've been a cyclist and/or a runner pretty consistently for the last 20 years. This year I moved to a place where cycling wasn't an option (without driving a long way), and at the same time I injured my knee by overtraining on hills. So I was benched from my typical cardio. The results are unsurprising... I gained 15 pounds over the next 6 months, and am now overweight. Exercise obviously plays a rol…

The article seems to indicate that, counterintuitively, your Total Energy Expenditure (TEE) wouldn't have changed much after you stopped the regular cycling (see the section about how hunter gatherers walking 8-14 km a day had the same TEE as average US), so your weight gain may have been from second-order effects of coming back to your diet.

Do you remember whether your diet changed at this time as well?

Some other anecdotes shared here seem to share a similar theme, that exercise helps in losing weight on a more meta-level by shifting yourself into a generally healthier mindset which, in turn, seems to help you eat "healthier" foods, which is probably a proxy for "low-calorie foods" like fruit and vegetables. Maybe when you're sedentary it's easier to reach for the bag of potato chips?

Re: Scientist busts myths about how humans burn calories

#672

Post by throwaway09223 » Fri, Feb 18, 2022, 6:03 PM UTC

nradov wrote: post #661

throwaway09223 wrote: post #577

Earlier quoted context omitted.

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 betw…

It seems doubtful the measurements would be far off. The numbers fit with the expected 50 or so calories per mile biked.

Re: Scientist busts myths about how humans burn calories

#673

Post by dahart » Fri, Feb 18, 2022, 6:04 PM UTC

amelius wrote: post #597

rob74 wrote: post #349

Earlier quoted context omitted.

Congratulations! I would be happy to lose "only" 10 kg (hell, 5 kg would be good for a start), but since Covid and home office my weight has been (slowly, but steadily) going in the wrong direction. Yeah, you can and do burn calories by exercising, but it's depressing how little it is. And it's also depressing if I look at the graph that some 40 to 50 year olds seem to still have the metabolism of a toddler - I'm def…

> I would be happy to lose "only" 10 kg (hell, 5 kg would be good for a start), but since Covid and home office my weight has been (slowly, but steadily) going in the wrong direction. Yeah, you can and do burn calories by exercising, but it's depressing how little it is. Had the same problem. Then switched to intermittent fasting. First two months, nothing happened. Then within a month dropped 10 kg, which got me bac…

Isn’t 2.5kg / week weight loss extreme, and unhealthy or bordering impossible? It seems to be usually recommended to stay below 1kg per week, a healthy rate seems to be closer to 0.5kg/week. I’d assume that something might have been happening the first two months. Could be a measurement problem as well, that you were catching water-weight highs and then maybe changed the timing of your measurements? If you were actually losing closer to 0.8kg / week without knowing it for three months, that’d be about 10kg.

How much more are you eating exactly? Have you changed your exercise routine or physical habits? The problem with calling CICO stupid is that it’s two-thirds physics. The only way to gain mass is to eat it, and the only way to lose mass is to burn it off through RMR and exercise. There’s mountains of data demonstrating that humans gain weight when eating more than they burn, and lose it when burning more than they eat. The people who seem to lose/gain weight abnormally are just people who’s bodies burn calories in unusual ways. That’s rare and statistically unlikely, but even that still follows CICO.

Re: Scientist busts myths about how humans burn calories

#674

Post by throwaway09223 » Fri, Feb 18, 2022, 6:05 PM UTC

eli_gottlieb wrote: post #639

throwaway09223 wrote: post #118

Earlier quoted context omitted.

> if I go all out on a row machine for 30 minutes, I'll burn 300 calories. A stationary bike at a steady 20mph pace is about 500 calories in 30 minutes. That's really significant. An hour will erase about a third of a normal person's diet. When I used to do heavy training (long distance running, weight training) I would eat close to 8k calories a day and I was in fantastic shape. Eating more was necessary to survive,…

>An hour will erase about a third of a normal person's diet. Pretty sure most people shouldn't be eating 3000 calories/day.

Probably not, but the average American does eat about 3600/day.

Re: Scientist busts myths about how humans burn calories

#675

Post by nradov » Fri, Feb 18, 2022, 6:06 PM UTC

ajuc wrote: post #283

y4mi wrote: post #266

Earlier quoted context omitted.

And yet the article you're commenting on says that you don't burn more calories by exercising... If it is true, it definitely changes the narrative.

The article says you can't keep unhealthy diet and get fit just by exercising. Which is true in my experience as well - I was eating over 3000 kcal a day before I started counting calories, and if I haven't reduced that - no reasonable amount of exercise would have helped. What's tricky is that in early 20s I was eating about as much and it was fine.

There's a huge variation between individuals based on size, sex, and activity level. As a large, fairly active man I have to consume around 3100 kcal per day just to maintain body weight. But a small, sedentary woman might gain weight with even half that consumption.

All else being equal, resting metabolic rate doesn't tend to slow down much as we age. The notion that people in their 20s can eat as they want without gaining weight is mostly a myth. It's more likely that you don't accurately remember what you consumed and your activity level in your early 20s.

Re: Scientist busts myths about how humans burn calories

#676

Post by Invictus0 » Fri, Feb 18, 2022, 6:12 PM UTC

verisimi wrote: post #589

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".

The problem is that the funders of scientific research (corporations, governments, military) see zero upside in finding simple answers. There's simply no money in 'better living'. This sort of research is only of value in so far as it moves forward some sort of saleable treatment. In the meantime, the more confused you are about what to eat and how to treat your body - the better. It is when people are damaged that t…

The military has no interest in figuring out how the body expends energy?

Re: Scientist busts myths about how humans burn calories

#677

Post by JeremyNT » Fri, Feb 18, 2022, 6:15 PM UTC

coryfklein wrote: post #671

JeremyNT wrote: post #659

Earlier quoted context omitted.

My own anecdote: I've been a cyclist and/or a runner pretty consistently for the last 20 years. This year I moved to a place where cycling wasn't an option (without driving a long way), and at the same time I injured my knee by overtraining on hills. So I was benched from my typical cardio. The results are unsurprising... I gained 15 pounds over the next 6 months, and am now overweight. Exercise obviously plays a rol…

The article seems to indicate that, counterintuitively, your Total Energy Expenditure (TEE) wouldn't have changed much after you stopped the regular cycling (see the section about how hunter gatherers walking 8-14 km a day had the same TEE as average US), so your weight gain may have been from second-order effects of coming back to your diet. Do you remember whether your diet changed at this time as well? Some other…

I am pretty sure my diet stayed pretty tight, as I monitor my caloric intake using my smartphone and it remained pretty consistent. Obviously this could be skewed for other reasons so it's not gospel.

The "much" is carrying a lot of weight, so to speak, in your comment. As a reference I went from running ~25 miles a week to just walking a fraction of that as I've recovered. I did keep up my other non-cardio calisthenics throughout, though.

Some napkin math suggests I was over my calorie target by just shy of 300 calories per day over the course of this time period.

Re: Scientist busts myths about how humans burn calories

#678

Post by csee » Fri, Feb 18, 2022, 6:17 PM UTC

deepnotderp wrote: post #663

csee wrote: post #335

Earlier quoted context omitted.

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.

  >  The implication of this is that somehow the sedentary lifestyle of your average couch potato is the "normal" lifestyle for a body, and the lifestyle of a hunter gatherer is "overactive", and their bodies are chronically tired and trying to reduce their metabolisms. That... seems quite unlikely.

  >  the implication is that the Hunter gatherer lifestyle is a chronically tired lifestyle for human bodies.

I can't make sense of these statements.

The author thinks that couch potatoes have more stress and inflammation (and probably more fidgeting, etc, too), and these things burn calories which explains the results. That's the opposite to what you say here, which is that the results suggest that being a couch potato is normal.

Re: Scientist busts myths about how humans burn calories

#679

Post by dahart » Fri, Feb 18, 2022, 6:19 PM UTC

watwut wrote: post #270

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…

I dont know ... this one is often repeated. Including in context when completely sedentary people want to improve health (as opposed to "I want loose weight for aesthetic reasons"). > it never really worked because I’d unconsciously eat to compensate Your body is actually building muscles after exercising. It is also repairing damage caused by exercising. You actually should eat more, but more of the right stuff.

> You actually should eat more

I did… the problem with me (and with, I dunno, half of humanity? ;)) was I overcompensated, I ate more than I needed to build muscles and recover from exercise. So I gained weight slowly, or for long periods of time, just failed to lose the extra weigh I had through exercise alone. My problem is that exercise without calorie tracking doesn’t help me lose weight, I have to do both. And once I learned to do both, I automatically figured out at the same time how to lose weight without exercising at all. I still exercise, but now I get to use exercise as a way not just to get strong, but also to eat extra snacks. :)

Re: Scientist busts myths about how humans burn calories

#680

Post by dahart » Fri, Feb 18, 2022, 6:29 PM UTC

asiachick wrote: post #132

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…

This doesn't fit my observations entirely. I have a friend who runs several miles every morning. He says he does this so he can eat an extra 300-500 calories a day ... which he does. He's thin. I certainly get that less eating is more effective than exercise but in my head I think as long as you burn more calories than you take in you should lose weight. So if you eat 1800 calories a day, assuming you need 2000 a day…

FWIW, I agree with your observations, so it’s possible I gave the wrong impression. After learning how to track my intake, it changed my view on exercise, and sometimes I also use exercise as a way to eat more. :)

Like many people I consciously and unconsciously resisted the idea of tracking calories and using calories-in/calories-out (CICO) as my primary tool for both weight loss and exercise. It’s not perfect, as many people here are pointing out. However, it doesn’t need to be perfect, and there are scant alternatives that are demonstrably better. I changed my mind and now I see calorie tracking as a way to be better at both exercise and weight loss. Good exercise training, especially weight lifting, requires eating a bit more than expenditure, and good weight loss requires eating a bit less. Either way, I agree with you that exercise can play a valuable part in weight loss, and I think it has many other physical and mental health benefits.