2. Yam: Yam contains nutrients such as saponin, mucus, choline, starch, sugar, protein, amino acids, vitamin C, and various trace elements. Rich in content and nourishing, it is a good food for recovery after illness. Yam can promote the proliferation of T lymphocytes, enhance immune function and delay cell aging. Eating yam regularly can prolong life. Mucopolysaccharides in yam can form bones and make cartilage elastic. It is rich in vitamins and minerals, relatively low in calories and almost free of fat, so it has a good slimming and bodybuilding effect. Mucin contained in yam can prevent fat deposition in cardiovascular system and prevent arteriosclerosis. Eating yam can also increase human T lymphocytes, enhance immune function and delay cell aging.