Reasonable nutrition, also known as balanced diet, refers to a diet that provides the body with complete types, sufficient quantities and appropriate proportions of energy and various nutrients, and keeps a balance with the needs of the body, so as to achieve reasonable nutrition, promote health and prevent diseases. Its basic requirements are as follows:

First, provide a full range, sufficient quantity and appropriate proportion of nutrients. China Nutrition Society divides human food into five categories: the first category is cereals and potatoes, cereals include rice, flour and miscellaneous grains, and potatoes include potatoes, cassava and sweet potatoes. The second category is animal food, including meat, poultry, fish, milk, eggs and so on. The third category is beans and nuts, including soybeans, other dried beans and nuts such as peanuts, walnuts and almonds. The fourth category is vegetables, fruits and bacteria and algae. The fifth category is pure energy substances, including animal and vegetable oils, starch, edible sugar and wine. It is suggested that the daily diet should include the above five categories of food, with 2 ~ 4 kinds of food for each category, and at least10 ~ 20 kinds of food should be eaten every day, reaching the best of more than 30 kinds.

Second, ensure food safety. Food must not contain all kinds of harmful factors that are harmful to human body, and food should be kept fresh and hygienic to ensure the safety of residents. Once food is polluted by harmful substances or spoiled, nutrients in food will be destroyed, which will not only fail to meet the nutritional needs of the body, but also cause acute and chronic poisoning and even cancer.

Third, scientific cooking and processing. The scientific processing and cooking of food aims at eliminating anti-nutritional factors and harmful microorganisms in food, improving the digestibility of food, changing the sensory characteristics of food and promoting appetite.

Fourth, a reasonable dining system and good eating habits. According to the physiological conditions, labor intensity and working environment of different groups of people, the dining system is arranged reasonably. Reasonable dining system is helpful to promote appetite and regular secretion of digestive juice, so that food can be fully digested, absorbed and utilized. Adults should adopt the system of three meals a day, and develop good eating habits such as not being picky about food, not being partial to food and not overeating.