"Diabetic food exchanges are an easy way to create a meal plan that has a variety of choices while making sure that the consumption of carbohydrates is controlled. Similar foods are grouped into categories — or "exchanges" — that have the same amounts of carbohydrates, protein, calories and/or fat. Meal plans, which are usually devised by you and a nutritionist, specify the number of servings you can have from each exchange list. Foods on the same list can be exchanged for each other, to give variety and choice to an otherwise structured meal plan.
So, for instance, say your snack can have two carbohydrate exchanges. That would mean you could choose to have two slices of bread, or a cup of milk and an apple. You can mix and match according to your preferences, but the exchange system gives you a way to quantify how much of what kind of food you can have."