Yin Yang balance is an ideal condition for the body. When Yin and Yang in the body get balance, both physical and mental condition of the person reach the best condition. In theory, if one can keep this condition, he/she can get eternal life. In China, balancing Yin Yang in the body is a traditional health concept, and adjusting Yin Yang in the body with food is a traditional way to protect health. Eating different food in different seasons to fit the different Yin Yang relationships in the environment is a part of the practice.
Spring is a season for growth, however, many diseases "grow" also in the season. In spring it is important to enfore the defending system of the body. It is important to cultivate Yang in the body to enforce the defending system. The key to cultivate Yang is maintaining the liver. Man should eat much fresh vegetables, less sour, spicy and fried food, drink more water and less alcohol; sleep enough and keep good mood. In the earlier spring, it is still cold, although Yang is increasing, man should eat food which is Yang but not strong Yang, for example, chives, garlic, onions, leeks, coriander, ginger and conjac. In middle spring, man should eat yalms, dates, honey and celery which are mild Yang. It is important to get enough vitamin to strengthen the defending ability of the body. In late spring, the temperature is high, Yang is too strong, the inside of the body can be too hot. This can cause that the liver is too hot and it is easy for man to be angry. Man should eat food which can decrease the heat in the body and protect the liver. The suggested food are buckwheat, shepherd's purse, spinach, celery, lettuces, eggplants, cucumbers and mushrooms. Most of the fruits matured in the spring is sour, man should not eat too much. It is better to eat bananas, sugar canes, nuts and persimmons.
In summers, there is too much heat. It is important to reduce heat and increase appetite. Man should eat eggplants, lotus roots, green bean sprouts, gourds, cucumbers, melons, watermelons, tomatoes and other food which are good for supplying water to the body and cooling the body. The old should be careful for fat food, and the weak should not eat cold food and raw food to avoid getting troubles in the digestive system. According to Traditional Chinese Medicine, suitable food can compensate the nutrition missing caused by water loss. Huangdi Neijin advocates that man should sleep later and get up earlier in summer, because when the temperature is too high, Yin is not enough and Yang is too much in the environment. It is difficult to get Yin Yang balance in the body if man sleeps much. Additionally man should have some sports although it is too hot.
Summer is the season in which Yang in the environment is strongest. The metabolism in the body is active, so it is easy to be tired. The temperature is high, so it is easy to lose water from the body. The key to keep health is reducing heat and increasing Yin in the body. Proper foods are, chrysanthemum, celery, cabbages, parsley, bitter gourds, carrots, bamboo shoots, cucumbers, melons and other food which are good for decreasing heat and supplying water; fish such as herrings, carps and silver carps; spinach, longans, litchies, peanuts and tomatoes. Man should eat more grains, fruits and vegetables. However, man should not eat too much cold food to avoid Yin increase too much in a short time.
In autumn, Yang becomes weaker and Yin increase day by day. It is often too dry. Temperature difference between day and night is big. It is easy to be sick. Old sickness often come back in autumn. Keep moisture in the body is the key word for health. According to traditional Chinese medicine gruel is very healthy breakfast in autumn. Other suggested food are Lily, white fungus, yam, pears, grapes, water chestnuts, rice, sugar canes, soy, sesame, lotus roots, spinach, lungs, turtle meat and olives. Man should eat less leeks, garlic, ginger, chilis and other spicy food. Fruit tasted sour are good for preventing evaporation. Apples, pomegranates, grapes, mangoes, grapefruit, lemons and hawthorns are the fruit suggested for autumn. In addition, autumn is a season to eat tonic food for improving defending system for winter, because in winter Yin is strong, and the body is weaker.
In winter metabolism is slow and the defending system is weak in the body. Winter is the season in which cardiovascular diseases and respiratory diseases often happen. According to Traditional Chinese Medicine, every life in the winter tries to save Yang in the body while it waits for spring. Man can save Yang in the body with these effective measures: sleep earlier and get up later to reducing disturbing of Yin in the environment; keep the body warm, especially keep the back warm, because back is the most important part of the body for saving Yang; eating tonic food. The suggested food are muttons, shrimps, leeks, longans, mushrooms, chestnuts, walnuts, turtles, potatoes, Chinese cabbage, cabbage, radish, bean sprouts, mung bean sprouts and rapes. Man should eat less water chestnuts, persimmons, raw carrots, raw cucumbers, watermelons and ducks. Man must not eat too much to avoid diseases of circulatory system. Man should also avoid to use alcohol to defend coldness.