The four seasons in nature are characterized by spring, long summer, autumn harvest and winter storage. According to the theory of traditional Chinese medicine, the basic principle of four seasons health preservation is "nourishing yang in spring and summer, nourishing yin in autumn and winter". Therefore, the four seasons diet aftercare should also follow this principle.

The principle of spring diet is to reduce acid and sweet, and choose spicy and warm products. Diet should be light and delicious, avoid sour, greasy and cold things, and eat more yellow-green vegetables.

Summer diet is hot and sour, less cold and less cold drinks. Choose light, refreshing, less greasy and digestible food. "Summer tonic" should warm yang and adjust yin.

The principle of autumn diet is to add less bitterness, prevent dryness and protect yin. For example, eat less spicy products such as onions, ginger, garlic, leeks and peppers, and eat more sour fruits and vegetables. Eat more sesame seeds, walnuts, honey, glutinous rice and dairy products.

The principle of winter diet is to reduce salt and increase bitterness, protect yin and suppress yang. Appropriate intake of soft-shelled turtle, soft-shelled turtle, lotus root, flax, fungus, etc. Tonifying in winter should be based on nourishing yin and protecting yang.