This happens to us - if I cook dinner for everyone, two of us eat, if I cook dinner for two of us, everyone wants to eat. If I make enough for leftovers, nobody takes them to lunch. If I don’t make enough, they ask why there is not enough for lunch.

Things that help on your question though -

Canned beans, canned tomatoes, canned coconut milk, canned pumpkin, jarred spaghetti sauce, spices - a lot of our staples are not perishable.

Do you live where you can stop by the store on the way home? Then don’t buy perishables for the week, buy them for the meal you are making.

Some foods and meals freeze pretty well, freeze them and keep a list of what’s in the freezer so you remember to eat it.

I hate meal planning but it helps a lot. I sometimes put a note on the fridge “we have food for dal with spinach, chicken & cabbage, sheet pan gnocchi with sausage and broccoli, eggs and potatoes” or whatever we have the food to make, and cross them off as they are made.

Some foods make other foods. So if I make a hunk of pork, it’s pork, rice and beans then enchiladas then burritos, and so on.