I'd say you're absolutely right!
Nutrition is the remedy to almost anything (these days there are more and more articles on the bowel system flora's connection to depression etc). And as for shedding pounds, a person would have to exercise quite a bit to lose weight but maintain unhealthy eating habits.

Eating proper food enough many times a day helps on so many things, with me it's at least temper(haha), concentration and general feeling of being content

Excellent post!