The first category: cereal potatoes, including cereals (including rice, wheat, corn, millet, barley, oats, buckwheat, etc.) and potatoes (including potatoes, sweet potatoes, cassava, etc.). Because miscellaneous beans (including red beans, kidney beans, mung beans, peas, broad beans, etc.) are usually eaten in a whole state, they are often used as staple food materials, so they are also placed in this category. This kind of food is rich in carbohydrates and is what we usually call the staple food.

The second category: vegetables and fruits, which are rich in vitamins, minerals and dietary fiber.

Category III: Animal foods, namely livestock, poultry, fish, eggs and milk, can provide sufficient protein.

The fourth category: soybeans (including soybeans, black beans and green beans) and nuts, which mainly provide protein, fat, minerals, B vitamins and vitamin E.

The fifth category: pure energy foods, such as cooking oil and white sugar.

Variety of food

No food can meet the energy and all nutrients needed by the human body except breast milk for infants under 6 months old. Therefore, only a diet consisting of a variety of foods can meet the human body's needs for energy and various nutrients. The variety of food is quantified by kinds. It is suggested that the average number of kinds of food that are not repeated every day should reach more than 12, and more than 25 kinds every week, excluding cooking oil and condiments.

Distribution methods of 12 foods per day and 25 foods per week among the above five categories of foods: cereals, potatoes and miscellaneous beans: average 3 kinds per day and at least 5 kinds per week; Vegetables and fruits: average 4 kinds per day, at least 10 kinds per week; Livestock, poultry, fish and eggs: 3 species per day, at least 5 species per week; Milk, soybeans and nuts: 2 kinds per day and at least 5 kinds per week.