Food, diet, nourishment...
Kind of non-issue for me.
44 yo, no known health issues, more or less the same weight for the last 20 years.
I eat whatever I like whenever I like, just try to not have too large portions at once.
My "diet" to achieve this stability is simple :
if I start to have trouble fitting in my old size pants/trousers/shirts,
it means I have to eat less and restrain myself from any snacks between main meals until I can fasten my buttons with ease again.
And then, everything is allowed again, even ice cream late at night etc.
My vanity is taking care of the weight control, switching me into correct "nourishing mode" when it's necessary.