Well it depends on what kind of food brand is in the box. If it is cereal or cookies after the expiration date they will be stall.
NutriSystem food only lasts as long as the expiration date states. Once they have gone past the expiration date then the food is has gone stale.
Usually until the expiration date.
Most food has an expiration date if it's packaged.
Read carefully. It is NOT an expiration date. Only baby food has expiration dates. It is "best by" or "use by" recommendations. Extracts have alcohol in them. Unless the lid was off and the alcohol evaporated nothing goes wrong. With time the taste of the extract MAY degrade but it does not expire.
As long as the can is not damaged....for as long as you can think. (Unless it has an expiration date on it!)
3 months afterwards
Who knows? Is there an expiration date? If not, check their website (if they have one.)
In theory: Quite some time. In fact: Canned food becomes more and more tasteless and unappetizing as it ages. In practice: Discard canned food past it's expiration date.
Every package of salami should have an expiration date that you should go by. If there is no expiration date, the salami should last up to week after opened if in a sealed package or container.
The can should have an expiration date on it. That doesn't mean that it is bad once that date has passed, but could be risky.
Maalox is no longer any good after the expiration date. When the expiration date has passed it means that it is no longer as effective as it once was.