Detailed Explanation of the Chinese Dietary Guidelines: The Health Benefits of Food Diversity, Vegetables, Fruits, and Tubers

Human food is diverse. The nutritional components of different foods are not entirely the same. Except for breast milk, no single natural food can provide all the nutrients the human body needs. A balanced diet must consist of a variety of foods to meet the body's various nutritional needs, achieve proper nutrition, and promote health. Therefore, it is recommended that people consume a wide variety of foods. A variety of foods should include the following five categories: The first category is grains and tubers: grains include rice, wheat, and miscellaneous grains; tubers include potatoes, sweet potatoes, cassava, etc., mainly providing carbohydrates, protein, dietary fiber, and B vitamins. The second category is animal-based foods: including meat, poultry, fish, milk, eggs, etc., mainly providing protein, fat, minerals, vitamin A, and B vitamins. The third category is legumes and their products: including soybeans and other dried beans, mainly providing protein, fat, dietary fiber, minerals, and B vitamins. The fourth category is vegetables and fruits: including fresh beans, root vegetables, leafy greens, and solanaceous vegetables, mainly providing dietary fiber, minerals, vitamin C, and carotene. The fifth category is pure energy foods: including animal and vegetable oils, starches, sugars, and alcoholic beverages, primarily providing energy. Vegetable oils also provide vitamin E and essential fatty acids. Grains are the staple of the traditional Chinese diet. With economic development and improved living standards, people tend to consume more animal-based foods. According to the 1992 National Nutrition Survey, in some relatively affluent families, the consumption of animal-based foods has exceeded that of grains. This "Westernized" or "affluent" diet provides excessive energy and fat while being too low in dietary fiber, which is detrimental to the prevention of some chronic diseases. The recommendation of grains as the staple food is to remind people to maintain the good traditions of our Chinese diet and prevent the drawbacks of diets adopted by developed countries. In addition, attention should be paid to a balanced diet, regularly consuming some whole grains and mixed grains. Rice and wheat should not be milled too finely, otherwise most of the vitamins, minerals, and dietary fiber contained in the outer layer of the grain will be lost to the bran. Vegetables and fruits are rich in vitamins, minerals, and dietary fiber. Vegetables come in a wide variety, including leaves, stems, flowers, berries, fresh beans, and edible algae. The nutritional composition varies considerably among different varieties. Dark-colored vegetables, such as red, yellow, and green vegetables, contain more vitamins than light-colored vegetables and most fruits. They are major or important sources of carotene, vitamin B₂, vitamin C, folic acid, minerals (calcium, phosphorus, potassium, magnesium, iron), dietary fiber, and natural antioxidants. Wild fruits developed in my country in recent years, such as kiwifruit, prickly pear, sea buckthorn, and blackcurrant, are also rich sources of vitamin C and carotene. While some fruits may contain less vitamins and trace elements than fresh vegetables, they are richer in glucose, fruit acids, citric acid, malic acid, and pectin. Red and yellow fruits, such as fresh dates, citrus fruits, persimmons, and apricots, are rich sources of vitamin C and carotene. Root vegetables are rich in starch, dietary fiber, and various vitamins and minerals. Over the past decade, Chinese residents have consumed relatively few root vegetables; therefore, their consumption should be encouraged. A diet rich in vegetables, fruits, and tubers plays a vital role in maintaining cardiovascular health, enhancing disease resistance, reducing the risk of dry eye syndrome in children, and preventing certain cancers.