hmm...these are general guidelines, but try consuming 10x your body weight in calories. so if you weigh 200lbs, consume 2000 calories or less.

as for foods, dont eat the obvious crap like junkfood. you dont have to do anything extreme, just use common sense. try to eat natural and perishable foods instead of processed goods. easy way to tell if food is fresh: think about a grocery's store layout. most are laid out like this when you walk in:

a |_____________| c
bbbbbbbbb

a = wall with fruits and vegetables
b = back wall with dairy/eggs
c = wall with meats

the reason why A,B,C are along the walls is because they need refrigeration. most of the stuff in the aisles can sit on a shelf and are processed and nonorganic.

food for thought