Comment by noduerme

>> somehow the sedentary lifestyle of your average couch potato

What I got out of the article wasn't that sitting still and not thinking can somehow burn calories; just that strenuous mental activities can burn a great deal more energy in humans than in apes. This is believable to me. I'm a person who falls asleep doing math in my head every night. I got a chance, during a year of pandemic lockdown, to experiment with my own body in this way.

I only eat once per day. I don't keep fixed hours; sometimes I'll stay up for 24, sleep for 16; other times I'm regularly 8/16 sleep/wake. I don't have a set bedtime. I try to maintain 16/48 sleep/wake over any given period.

No matter what, I only eat one meal every 24 hours. I've been doing this for about 20 years.

This makes it easy to measure when I get hungry in relationship to my last meal. My body is well trained to expect about a 24 hour delay; I have no appetite and don't think about food until around 22 hours post-dinner.

Under lockdown conditions, I began to notice that I wasn't hungry as expected on days where I hadn't spent >= 6 hours working on strenuous code. If I took a day off and "couch potato'd", I might not eat at all for 48 hours. But if I focused on code for 8+ hours, I would be hungry on time or early.

I started to experiment with this. I figured out that if I took a 1 hour walk, plus 4 hours programming, it made me hungry right around where 6+ hours of code did. A 1 hour walk - to me - seems about equal to 2 hours of writing code in terms of what my body feedback gives me about my calorie burn.

I don't walk very fast, and I code very intensely.

But that's just it - this article is about solving math problems as a way to burn calories. I have a nice new M1 Mac that only ever turns its fans on or gets warm when I'm using all 10 cores. Last night my task falling asleep was to calculate randomly chosen x/128ths as percentages to five decimal places. My daytime task was harder; and now I'm hungry. And I haven't walked anywhere today.

However: Couch potato, this ain't. And the point about the body's reduced expectation of physical output is probably accurate as well.