Bravo Cookie2!!! That is an excellent example of how easy it can be done.
For us, our food budget is $150/month. But we actually get more value than that.. Here is how it breaks down.
DS can have reduced lunches at school, which amount to about $10/month during the school year. I sometimes allow him to have breakfast at school as a special treat.. and at 30 cents for pancakes or waffles (that he almost never gets at home) it is an inexpensive treat. (140 budget left)
We belong to a nonprofit service organization (like a gleaners) for $45/month. The fee goes towards the cost of running the organization as all the food is donated. We end up receiving 200-400 in food a month & paper supplies for my $45.. and sometimes we even get great quality used clothing for free as well! (95 budget left)
My daughter is on WIC which gives us a food value of ~90/month for free.
my $95 budget goes towards meat, fresh veggies, and odds & ends that I can't pick up from my above sources. When I go to costco I usually spend about $25 for string cheese, carrots, lettuce and a couple of odds and ends (what ever is on sale with a coupon in that budget) Everything else I spend at the grocery store.. usually as a loss leader, but not always.
So, yes we only spend $150/month, but we easily eat over $400 in food over the month. This budget does not include cleaning products or pullups.