DH, me, DS15, DD12, DS10, all very active in sports.
$500/month typically, mostly groceries. I shop sales, use coupons some. (no double coupon places here) When things are on sale for my pantry or freezer, I STOCK UP.
We buy few convenience foods. I try to hit all 5 food groups for dinner. Meat is mostly $2-2.50/lb, lots of lean burger, ground turkey or chicken breasts. Fresh fruit & veggies, whole wheat pasta, high fiber bread, lots of yogurt, milk & cheese.
Breakfast is cereal, toast, bagels, sometimes fiber one/breakfast bars if someone is running late. Plus juice, milk, coffee.
Kids eat lunch at school. I could make lunches cheaper at home, but I struggle to find things they really like in cold lunches, and working full-time, this just works.
I use the crock pot alot to avoid eating out. Works well for us.