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Comment by paulpauper | Hacker News Reader

it is even worse than that. the energy constrained model suggests it is impossible to ever work off a pizza. you just simply burn fewer calories later to negate exercise, such as lowed BMR or less NEAT. As you lose weight, your constraint is lowered and any calories above it will produce weight gain regardless of exercise.

The constraint throws off all the calorie math in regard to exercise. You find that no amount of exercise helps at producing lasting weight loss even if the meter/app says you burned 700 or whatever, which is .2 lbs. If you do this for 10 days you should lose 2 pounds of fat , keeping diet constant, but you don't. Either you lose less or just water.

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I find it very hard understand your paragraphs.

> (when i eat a pizza) i simply burn fewer calories later to negate exercise, such as lowered BMR/NEAT. as i lose weight my constraint is lowered. (constraint of what?) and any calories above it (above what?) will produce weight gain regardless of exercise.

what does this have to do with pizza? eating pizza negates exercise through lower BMR/NEAT: umm are you sure it's negating exercise itself? so michael phellps cannot possibly burn off a pizza? it's physically impossible?

felt compelled to comment cuz while i understand the terminology and know about this subject, i think its the particular form of writing that's just very hard to understand. thought you should know.

edit: i think you're saying you can't out work a bad diet. i usually hear it from the opposite pov: if you fast your body will compensate through lowered BMR/NEAT and so it's diminishing returns. surprised to hear your point seems to be it's physically impossible to burn off a pizza because a pizza will negate (seemingly any and all attempts at) exercise. ???

If only we could find some way to harness the power of these thermodynamics-violating pizzas.

Obviously this isn't completely correct, because elite athletes work to eat 6000 calories/day and manage to "burn it off."

That said, it seems clear that exercise does not help most people lose weight; adding a small amount as you're losing weight may be a way to retain more muscle mass and improve health in other ways, though.

Exercise helps people to lose weight. Just go to a local group bike ride. Then first observe average BMI there and then talk to people and you will find out a lot of them started fat. The problem is that people delude themselves about calories - both burnt and eaten. For example riding a bike at somewhat brisk but sustainable (for a healthy average man) pace may burn 500kcal per hour (that would be around 140W). Similarly running or walking for 7km as 70kg person burns around 500kcal. You do it 7 days a week and you still can't really eat more than your baseline if you want to lose weight. We can argue if 7 hours a week is a lot of exercise or not but most people would feel they exercise a lot and use that as justification to eat more.

The problem is that we are so sedentary that a very mild volume of exercise like 7 hours a week (let alone things like going to the gym 4 days a week) is seen as "very active lifestyle" and used as license to eat a lot.

Unfortunately you're still sedentary if you do that and sit at the desk, drive a car or lie on a sofa for the rest of the day.

It's not like adding more exercise is bad. It's the fact people are sedentary, drive everywhere that it's not feasible for them to get to activity level to really make a dent. Imagine you have to walk to your office for 30 minutes every day (and then back) then walk to a store to buy food. Then do some sports on top of that and suddenly the amount of food you can eat changes drastically.

Unfortunately it's very hard to do in today's world. We even started SUV'ing children to school instead of letting them walk. No wonder almost everyone is getting fat and complains that "no amount of exercise makes a difference".

When I look at photos of my parents in their 20s I struggle to see any fat people. Almost no one had a car back then (in my country) and that needed to walk a lot just to get to school/job, buy food, get anything done around the town (no online forms back then). People usually attribute it to food availability but when I try to estimate how much they needed to walk every day I see a completely different picture.

> Exercise helps people to lose weight.

Exercise has been extensively studied in relation to weight loss, and has been found to be of limited effectiveness. Many studies found no effect, and meta-analyses found modest effect sizes.

Your anecdotes don't change my mind. The problem seems to be, exercise uses up willpower and makes you want to eat more, and only in very indirect ways (improving BMR, etc) really helps.

Of course, exercise improves a bazillion other things: cardiovascular health, blood pressure, insulin resistance, etc, etc, etc.

"Uses up willpower," I thought, was also studied and found to be lacking as a thing?

I think it is fair that "exercise" in the form of specific activity with the sole purpose of doing the activity is likely much harder to get results from than folks admit. I think it is also fair that getting more active, period, is more effective than people will admit. You don't have to have a gym membership to keep from getting over weight. You do have to be active.

I don't think your basal metabolic rate goes down to zero as you increase exercise. There's probably at some point in which your daily total expenditure must increase, but it's unsustainable.

That sounds idiotic. I'm on a very clear downtrend in weight and on days where I burn more calories I eat more to avoid going into too high a deficit.

(cycling workouts with power meter or on Zwift, accurate calorie counts)

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