Three adults here. We budget $200 per month for groceries, but we rarely spend that much. DH works for a food manufacturing company so we get a lot of meat (mostly chicken and some pork) and frozen food for free. Additionally, he gets a $100 perfect attendance coupon every three months which we use at the steeply discounted company store. I can fill an entire deep freezer off of just one $100 coupon.
We also have a small grocery store that sells whole bulk beef for less than $2 per pound. It costs extra to have them slice it up into steaks or roasts. Fortunately, I have a meat slicer and a vacuum packer so I slice them up myself while freezing them into one meal portions. Their sales are infrequent so I try to stock up when I can. DH hunts so we usually have a full supply of venison. I fish (and we live by a lake) so we have plenty of fish. DH even gets free fish bait from his work place (liver for catfishing). We also have chickens for eggs, goats for milk and meat, and grass fed beef that we raise ourselves. Between the meat slicer, meat grinder, and vacuum packer, we are able to handle a wide variety of our own processing.
On top of that, we grow most of our own vegetables. I do have to work on producing more fruit because we are having to buy it while we wait for our fruit trees to start producing.
Most of our food budget is spent on sugar, coffee, tea, spices, and condiments, but we do spend some on lunch foods, snacks, and drinks for DH to take to work with him for his lunches. We splurge on his take from home lunches a bit because he is the worst about wanting to eat out if he doesn't have enough junk food to satisfy him. He has pledged to get it together on this part of it, but we will see. If he does, we could easily cut our food budget in half just off of him and his lunches alone.