Anecdata, but I've found the same. I have more energy and better performance (for physical activity and cognitive activity) when I fast for the majority of the day.

Not a fan of gimmicky diets but my eating pattern seems similar to "the warrior diet", look it up if you're curious. I just think that in nature (if we were wild humans) we wouldn't have access to a huge meal right out of bed, We'd have to work hard all day to hunt and gather our food, then celebrate as a group with a food orgy around the fire.... okay I got a bit carried away :P

Agreed. I fast before working out in the morning, and usually break the fast by noon. On weekends I'll often eat breakfast and then fast the rest of the day.

I'm a woman, and on birth control, so fasting doesn't mess with my hormones so much, but I read that women tend to respond to fasting with heightened color vision and vivid sensorial experiences, which I can anecdotally confirm.

That said, I can only practice intermittent fasting for one to two days at a time before it starts negatively affecting my workouts and attention span.

Intermittent fasting is one of my favorite productivity hacks.

To anybody who decides they're going to try it: If you've gone through years of "6 meals a day" and suddenly fast for 24 hours, you're gonna have a bad time. Take it slow. Otherwise you'll feel cold, irritable, and distracted and will assume fasting is something only masochistic sociopaths can do.