Yin-Yang Foods

The Chinese believe that to achieve bodily harmony, you must balance your intake of yin (cool, bland) foods with yang (the rich and hot). They further believe that winter is yang season (the time for spicy, heavy food) and summer yin; that new mothers should eat yang foods, as should the chronically fatigued. Yin foods, on the other hand, are recommended for the irritable. The Chinese classify ailments as yin (cold) or yang (hot) and believe that as the body ages, it becomes increasingly yin. Such yin diseases as anemia are treated with yang foods, and assorted yang infections (sore throats, measles, etc.) with yin foods. Not all Chinese agree on which foods are yin or yang, but as a general rule, they break down as follows:

Yin Foods:
Bean curd and sprouts, all bland or boiled foods, the cabbage family, carrots and celery, cucumber, duck, some fish and fruits, American ginseng, most greens, honey, melons, milk, pears, pork, potatoes, seaweed and soybean products, white turnips, water and watercress, winter squash, most white foods.

Yang Foods:
Bamboo, beef, broiled meats, catfish, chicken and chicken soup, eggs and eggplant, fatty meats and fried foods, garlic and ginger, Korean ginseng, glutinous rice, green peppers, hot and spicy foods, leeks and onions, liquor, mushrooms, peanuts, persimmons, pig's knuckles and pork liver, red foods (beans, peppers, tomatoes, etc.) sesame oil, shellfish, sour foods, tangerines, vinegar and wine.

from foodwine.com