There is no single food that can contribute to longevity. A balanced diet can maximize the nutritional needs and health of the human body, and longevity is related to a number of factors, such as genes, sleep and diet. Food variety is the basic principle of a balanced diet. Food can be categorized into five major groups, including cereals and potatoes, vegetables and fruits, livestock and poultry, fish, eggs and milk, soybeans and nuts, and fats and oils. Different foods contain different types and contents of nutrients and beneficial dietary components. Only a diet consisting of a variety of foods can meet the body’s needs for energy and various nutrients. The Dietary Guidelines for Chinese Residents suggests that a balanced diet for Chinese residents should consist of a variety of foods, with more than 12 types of food per day and more than 25 types of food per week. It is recommended to formulate a reasonable and healthy dietary lifestyle under the guidance of a professional doctor.