For more than 50 years the exchange lists have been one method of meal planning for persons with diabetes as well as for those on weight-loss regimens. Little research has been conducted, however, concerning the methodologic basis of the system or its clinical effectiveness. Justification for specific food inclusions and general food groupings for the 1995 revision of the Exchange Lists for Meal Planning is provided by a database of foods and associated energy and macronutrient values. The mean energy and macronutrient values for each of the lists and sublists (starch, fruit, milk, and vegetables from the carbohydrate group; the meat and meal substitutes group, and the fat group) closely match the mean exchange values; however, the standard deviation and range are large. Interpretation of the database provides a rationale and guidance for decision making in clinical practice when using exchanges for meal planning, recipe, and food label calculations.