A well balanced diet is important for health and well-being. TCM has a sophisticated system of food categorization. Food items are described by their effect and are selected on the basis of their correspondence with an individual's pattern, influenced by climate, season, or type of illness. For example, people who are cold and dry need warm, moisturizing food. People who are hot and damp need cool, drying food. People with congestion need decongesting food. Diets are designed to counterbalance specific illnesses and conditions.