Get staples from food pantries, go shopping for things you can't get that way. Pantries near me often have more fresh produce than they can give away, you won't be taking it from someone else.

Aldi is cheaper than most other chain stores.

A lot of bakeries sell day-old bread at a markdown.

And if you're eating meat more than three times a week, you're doing it wrong. The less, the better, for your pocketbook and the environment.