Actually, the question to ask is, "How many grams of carbohydrate should I have at each meal?" Carbohydrate, a nutrient needed by the body for energy, is converted into glucose when it's digested. This, in turn, causes blood glucose levels to rise. So, someone with diabetes needs to control how much carbohydrate he or she eats. Sugar is just one type of carbohydrate; foods contain other sources of carbohydrate, too, like starch. If you only account for the sugar in foods, you'll miss out on other sources of carb, and that can affect your blood glucose. In general, most people aim for between 30 and 60 grams of carbohydrate per meal, and 15 to 30 grams of carb per snack. It's a good idea to meet with a dietitian to find out how much carb is best for you. In the meantime, start reading food labels for the serving size and the total carbohydrate grams (sugar is included in the total carb grams).