I get through 600g of mince to feed 15yo DD (eats an adult portion), 10yo DS1 (has hit puberty, is 5'1", plays a lot of football, ALSO eats an adult portion), 9yo DS2 (eats an average 9yo's portion of food, not an adult portion yet), 2yo DS3 (who eats like a sparrow / 8mo baby portion), and myself.
So for 3 adult portions, one portion a bit smaller, and a tiny portion, I get through 600g mince.
If you are doing 3 adult portions + extra smaller portions, then 600g mince is about right.
I've no answer on the chicken though - that's mental, 16 bits of chicken breast in 4 days?!
Bacon I can easily see 20 rashers going like that - at 3 rashers per sarnie, that's only 6 and a bit sandwiches - two bacon sarnies each at a lunch time.
Teenage boys in particular seem to eat about twice as much as a full grown adult - my already hit puberty, voice breaking, growing about an inch a day 10yo DS1 eats more than anyone else in my house.
Two teenage boys? at the food bill. I'm dreading when DS2 hits that point too.
Add in food 'issues', and I can see that it would get very annoying. (Mine also have food issues, but that's because of sensory issues from ASD)
Answers? Buy a set amount, meal plan, but allow for teenage boy's HUUUUGE appetites.
Microwave noodles are a good, cheap backup. I put chopped sandwich ham & sweetcorn in them.