The Food Exchange System provides a quick way to estimate energy, carbohydrates, protein and fat content in any food or meal.

Food from each exchange (starch, meat & meat substitute, fruit, vegetable, milk and fat) is defined so that one serving of each food contains the same amount of carbohydrate, protein, fat and energy (calories).

Free foods contain fewer than 20 calories per serving and less than 6 grams of carbohydrate per serving. Many vegetables are considered "free" foods, including celery, lettuce, spinach, cabbage, cucumbers and zucchini.

Moderation. is the key word . Eight (8)servings of a free food (160 calories) which is quivalent to one English muffin.