I (and my waistline) can personally attest to the high quality of Mrs Inor's cooking even if she is using nasty old stale outdated cans of food.The reason that everything edible (including drugs) has an expiration date or a use by date is due to federal law. There has to be a date. Now if you were a manufacturer you would make that date as soon as possible so the consumer will purchase more. But not so soon as to lose customers. In one of my canning books the authors came across some twenty five year old home canned beans. Looked good, smelled good, lab said it was still 90% nutritious and it tasted fine. I still use canned goods from the store that are "expired" (gasp) and they are just fine. Plastic water bottles I do wonder about - heard about the plastic degenerating - but is that advertising hype to get you to buy more water? You can't trust anyone these days. That said, trust me (LOL) I use up store bought canned goods within a year of the use by date.