Nutritionists divide food into six categories: cereals, lean meats, soy and dairy products, vegetables, fats and oils, fruits, and specify the calories and nutrients contained in the "equivalent exchange unit" of each food category.

(1) Cereals

Each equivalent exchange unit contains 90 kilocalories, of which 19 grams of carbohydrates, 2 grams of proteins and 0.5 grams of fats.

(2) Vegetable foods

Each equivalent exchange unit provides 80 kcal, of which, contains 15 grams of carbohydrates and 5 grams of protein.

(3) Fruit foods

Each equivalent exchange unit provides 90 kilocalories, of which, contains 21 grams of carbohydrates and 1 gram of protein.

(4) Lean foods

Each equivalent exchange unit provides 80 kilocalories, of which, 9 grams of protein and 5 grams of fat.

(5) Soy products and dairy foods

Each equivalent exchange unit provides 82 kilocalories, of which, 6 grams of combined carbohydrates, 4 grams of protein and 5 grams of fat.

(6) Fats and oils

Each equivalent exchange unit provides 80 kilocalories, of which 9 grams of fat. At the same time, nutritionists have determined that different varieties of food in the same food group provide the calorie and nutrient requirements specified by an "equivalent exchange unit". For example, a cereal "equivalent exchange unit" contains 90 kilocalories, 19 grams of carbohydrates, 2 grams of protein, 0.5 grams of fat.