Just like everyone else, WAY TOO MUCH! On average I spend $250 a week at the grocery store and that feeds 4 of us. That feeds me 3 meals a day since I take leftovers. I try to only eat out lunch once a week and I often do that on the weekend with the kids. We rarely eat out for dinner bc it is just too expensive. My husband takes breakfast and eats dinner with us, and just depending on what we had, often takes leftovers for lunch as well. The kids eat breakfast and dinner and snacks every week plus lunch on the weekends.
That bill though also includes household items, toiletries, beer, wine, batteries, detergent, etc etc etc.....I shop once a week and am a one stop shop person so that is just my weekly grocery bill but by all means is not JUST food.
This Summer with my stepdaughter here the bill each week was higher. I am working though now on cutting back on the excess leftovers and buying frozen veggies where it's appropriate. I do menu plan too from Sunday - Thursday each week and make a list and stick to it pretty closely.