That is too broad a question to be answered in any meaningful way. You
need to be more specific, either by food group or by whether you pay
attention to the "best if used by" date or some other measure.

That said, I keep cooked meat only 3 days because I have a fussy stomach. The same
goes for anything with cooked eggs. I keep anything with uncooked egg, like leftover
batter, only overnight. I keep canned food (stored in a plastic container) up
to a week. Anything else...if it looks or smells even slightly "off," out it goes.

N.