OK, maybe these are things you already thought of but my ideas after growing up with 2 teachers for parents (lord knows they don't get paid enough!!!)
First, do you buy name brand or store brand? Admitedly, some store brand products aren't as good, but, try everything possible before going back to name brand. Especially things like frozen foods and boxed dinners.
Second, cut back on snacks - chips and pop are two of the most expensive things you can regularly buy and they aren't good for your growing boys anyhow. You provide healthy food for them and let them spend their allowance on junk food. Get an air popper and popcorn and crackers and cheese and let that be the cheap snack around.
Third, coupons, coupons, coupons! Need I say more?
Forth, Walmart price matches, so sign up for the Sunday paper, go through all the adds (and get those coupons) and take the Meijer, Kroger, and Marsh adds with you to Walmart and have them price match on sales.
Finally, and maybe someone already mentioned this - I didn't read through very carefully, go to http://www.angelfoodministries.org/ and check out their menus. Some things aren't as good for you - breaded chicken, boxed meals, but over all, it's a great way to save money and an easy way to get staples - don't know if you can buy more than one box at a time or not.
Good Luck!