Comment by hombre_fatal

I can think of two major, extra lifestyle factors that increase calories in adulthood that we overlook in favor of more appealing explanations like "metabolism tho":

1. We eat out more as adults. Our skinny kid/teen selves didn't even have the money/vehicle/norm to eat out much less do it daily like we can as adults. This also includes eating out during our lunch break. Every time we eat out that's an easy 1000+ calories.

2. When you live with a partner, every time they ask "wanna eat something?" and you say "yes", that's a moment you wouldn't have eaten had you been a bachelor. We'll even say yes when we aren't hungry.

It's funny how much we want to believe in factors out of our control.