The fridge is full at the moment because we just had a delivery; there's a shelf for things to be eaten in next few days, a shelf for this week, and then other stuff. DH or I rotate everything when we fiddle about looking for meal ideas and are good at using up. When the fridge runs down we do one interim veg/carb shop and then another big delivery.
The cupboards and freezer are always well stocked including easy long life bits like part baked bread, carton juice. We keep a fair amount of bakery, meat and veg options in the freezer for when those run down; if we have too much veg on a short life then it'll be chopped and frozen to go into pastas. Leftover meals usually go in the freezer to do a single lunch or dinner, they get cycled through quite quickly. During covid we comfortably made a LOT of healthy meals just from the cupboards; pasta, rice, wraps etc are all easy when you have beans, chicken, onions, tomatoes, aubergine, courgette, leek, cauliflower plus all the spices and stores of sauce like chipotle and mayo. On rotation I'll totally run down veg, or freezer meat, or tins, or non-food (laundry, soap etc) and then restock, so none of it gets too old. DH thinks we have too much, but is surprised on the rotations when we run out of rice, tapenade, or whatever else. There's still plenty of food, we just have something else.
We rarely throw out more than a few bits; the food waste bin gets egg shells, fat, kitchen roll etc. I think that's quite common with both our families, we're all big on using up whatever. Does make me wonder how they are measuring quantities of household waste! Schools, hotels and restaurants will be much bigger contributors.