[dpark]

Your body is optimized for saving energy, because for millions of years starvation was a plausible outcome of wasted energy. This is the same reason sweets and fatty foods taste better than kale. You're evolved to prefer energy-dense foods.

Given that you post to HN, starvation is not a likely scenario for you. Diabetes, obesity, heart failure, these are all health issues you could face, and they are not things your body is evolved to avoid, because they were comparatively minimal issues for millions of years.

The "underlying physiological problem" is that we are just not evolved to overeat and be sedentary.

[whiddershins]

I don't think the data supports the scarcity hypothesis. Unquestionably we evolved to cope with scarcity. But humans often lived in periods of high food availability. I think it is reasonable to assume my body is evolved to deal with both high and low calorie environments, if it is functioning properly. Anecdotal data bears this out as well. There are many people, including myself, who have dramatically varied their caloric intake and exercise habits with fairly minor changes in body composition.

[dragonwriter]

> But humans often lived in periods of high food availability.

Outside of the post-civilization period (which is trivial in duration in terms of timelines required for substantial evolutionary change given human reproduction patterns), I don't think sizable populations of humans have lived for significant periods of times in conditions where large volumes of food were available that didn't require substantial physical exertion to access.

"High food availability", sure, that occurred, but that only means a low risk of starvation with exertion to extract food from the environment. It is a very different thing than being able to avoid starvation while spending most of your time sedentary.

[pbhjpbhj]

>But humans often lived in periods of high food availability. //

It's not just high food availability we have - I'm a few steps away from a ton of high calorie foods and could get more sent to my house without leaving my chair. In the past, even with plentiful supply, one had to [generally] put in some effort to get food. That doesn't seem to be the case for many now.

In the scenario of high food availbility meaning there's plenty of fruit to gather (and process to save for winter) and there's plenty of deer to chase then I can see I'd get more exercise.