I think partially its because evolutionarily speaking, high calorie foods like sugar and fats were rarer and useful. So the brain is like, ‘yes i need this to live, find more’

But now we live in a society that has all these resources and can exploit this, and we have to actively stop ourselves from over-indulging.

Ive heard - take it with a pinch of salt cos it might be bollocks - that thats why even as recently as a few centuries ago the western beauty standard was… plumper/chubbier. It signified wealth and prosperity, and i guess the ability to survive a lean winter