What are the basic 3 food groups?

The USDA Dietary Standards specify the objectives for each food group in cup equivalents (for fruits, vegetables, and dairy products) and ounce equivalents (for grains and protein foods). All food groups (proteins, fats, and carbohydrates) are essential as part of a balanced diet. Carbohydrate foods provide a wide range of nutrients, are low in fat, and are excellent sources of dietary fiber.