Sports is actually extremely inefficient when you look at the science. However, when you look at anecdotes, it seems to be consistently impactful. I think it's more an issue with how we're calculating calories out.

It will be hard to pick apart why. Muscles increase metabolism plus I suspect after a workout you feel like protein not carbs/sugar. You eat that and feel full. Then there is plain old confounding of people who have a good diet and people who exercise.

I think weight loss is more than just calories in/out. Maybe our body reacts to adapt to situations and tried to change the body shape to make it easier for itself. So I think healthy habits are more important and can depend on genetic history too.

I think emotions are a huge part of weight gain and loss and yet most Western medicine seems to almost completely ignore the impact of emotions on the body. Try eating a lot of food when sad—it's hard to take even a bite. Yet it's hard to even realize just how much one is eating when anxious.

I also imagine the emotions impact digestion and storage of fats and a lot more, basically adapting our bodies to our perceived environments, so it kinda baffles me that we don't study the emotional impact more.

Yes, I agree. I feel we are definitely missing out.

A clear example is something like cortisol. It damages your body to give you a short term advantage to survive a situation.

Being under stress might make you burn lots of calories, but stress ends up being weight gain in the long term because the body tells you to save up more energy for next time.

I am fairly certain I know the answer to this. They normally do these kind of studies on untrained humans, because the point is to prescribe (or not) exercise to people who need to lose weight, which are typically not athletes. The anecdotal success comes from people who play sports (tautologically). The problem is you cannot compare across these two groups because the metabolism and sheer volume of exercise is not comparable. Even a semi serious athlete will put in 5-6 hours of intense training a week. And their bodies are much more efficient, so they can burn way more calories in the same time. This is NOT the same as “Brisk walk and lift some weights 3-4 times a week” they prescribe the study group in a study of untrained athletes. Not even close.

I mean the typical advice I get is 1 hour of running burns as much calories as one large slice of pepperoni pizza (~700 cal). Trained or untrained, this seems off by a lot.

Why does it seem off? It's hard to measure calories when running, but with cycling we have power meters which are incredibly precise, and you will burn around 700 calories an hour (as a beginner). Trained athletes can burn maybe double of that.

Because it burns off about a whole large pizza's worth, rather than one slice, and I'm not trained.

Folks who can be bothered to put in the effort to commit to regular exercise are more likely to be able to be disciplined about what they eat. Levels of exercise are probably pretty well correlated with folks who are serious about their weight.

What do you think about sports (say badminton) compared to treadmill or cross-trainer for cardio?

If I end up burning the same amount calories? Because I find it much easier to burn calories playing badminton compared to treadmill..

The same thing as “don’t have unprotected sex and AIDS will go away”.

I think it is a bit different: I believe that a big reason for AIDS is lack of education about it and lack of access to protections.

Whereas in order to get weight loss drugs you need access to it.

I have unprotected sex all the time. I'm on prep. Maybe if I was on semaglutide I could eat carbs with out turning into a monster that wants to eat every cinnamon roll in existence. Idk.

This post is an “Ask HN” about trying weight loss drugs. I don’t think a comment suggesting that people who want to lose weight have low self-discipline and are lazy is very helpful.

The main mechanism is [eat less] --> [lose weight].

Some people find it difficult to eat less, hence the drugs to suppress appetite.

I would think that the main mechanism is that if you "use" more than you eat, then you lose weight. You have two levers to lose weight: "use more" and "eat less". And then there is the part where not everything you eat is egal, so "eat better", somehow.

Technically correct about the balance, but practically people overestimate the amount you can burn with extra activity. The main reason to exercise while losing weight is that if you do resistance training, you preserve more of your muscle and lose predominantly fat - it’s not to burn more calories.

And I disagree about emphasising “better” instead of “less”. “Better” than doesn’t lose weight.

Why estimate and not just calculate ? It’s not a hard calculation, walking calorie burn calculators are reasonably accurate. Walking just takes time, which you may value a little higher than burning calories.

> “Better” than doesn’t lose weight.

So you're saying that feeding oneself exclusively with chocolate will has the same result as feeding oneself with vegetables? Sounds counter-intuitive.

Let's say that you eat n calories of junk food every day (maybe that's all you eat or a part of your diet). Replace those with n calories of healthy foods. Great - you've probably made a good change for your health long term. But you haven't made progress towards losing weight because your calories are the same.

Now say you eat exclusively chocolate when you are hungry, during the whole day. And let's compare that to a day where you eat exclusively vegetables when you are hungry.

Will you have eaten the same amount of calories both days?