It is not hard to cook proper foods instead of relying on man-made junk foods. There are thousands of recipes on the iNet which one can follow. If weight conscious and diabetic start by lowering your carbohydrate intake. Eat organic whole grains, vegetables, fish and poultry, and fruits, and lean beef and pork. Avoid foods made with white flour; breads, crackers, pasta and white foods like rice and potatoes as these quickly turn into sugar after eating. Go here for suggestions and recipes http://www.atkins.com/Home.aspx
If nothing is open, bring food from home. As you well know,a well balanced diet, but one that omits sugar and very sweet fruits and is light on carbohydrates is the way to go. There are all sorts of books out there that can help you.