Hello dragonfly, welcome to the forum. I'll bet it's tricky buying food and preparing meals for everyone, especially because of the diet restrictions. As far as the diabetes menu goes, he needs to understand that the more carbohydrates he eats, the higher his blood sugar will be - and that's with or without meds. He needs to test to know how his body reacts to all food, how it affects his blood sugar, so he will know what foods to avoid. As an adult, he has the responsibility to take care of himself. If he doesn't, he's at risk of developing very serious health complications, which obviously can shorten life and/or create even more medical expense in the meantime. Anyway, living on a more restricted budget means eating more fresh food, not boxed or packaged. Vegetables, except potatoes, should be on his plate. He can saute them in a little oil or butter. Choose veggies he likes (and, again, no french fries or baked potatoes). Your supermarket may sell chicken pieces, frozen or fresh, in large bags that are much cheaper than smaller packages. I don't mean nuggets!
Those are breaded and will mess up his blood sugar. When I buy meat like this, I divide up the package at home into smaller, meal-size portions, wrap them up in plastic and put them in the freezer. In this way, I take out what we need for dinner. Check with the VA to see if they have classes for diabetics, too. Good luck and come back and let us know how it's working.