Sweet potato, also known as sweet potato, sweet potato, sweet potato and so on. Native to South America, it has been cultivated in China for a long time. Sweet potato feeds on the root tuber, which is smooth, crisp, round and long, and is hammer-shaped. Skin color is light red, light yellow and white. There are many varieties, such as white hearts, red hearts, Nanjing red skins, Qingdao purple skins and Zhejiang purple skins.

Sweet potato is sweet and flat. Cooked food is good at invigorating spleen and qi, moistening intestines and relaxing bowels; Eating raw is good for promoting fluid production and quenching thirst. It is suitable for adjuvant treatment of spleen and stomach weakness, emaciation, loss of appetite, mental fatigue, constipation, lung and stomach fever, thirst and dry throat. Regular diet can keep the elasticity of blood vessels, prevent the atrophy of connective tissue of liver and kidney, reduce weight and prevent arteriosclerosis. It is a world-recognized fitness longevity food with low price and good quality. It can be used for both food and vegetables, and is suitable for all ages in Xian Yi.

In some longevity areas and villages in Japan and China, it is found that local people take sweet potato as their staple food and eat it all the year round, so sweet potato is called "healthy and longevity" food. Sweet potato is a kind of common and economical nutritional health food, especially rich in carotene, which is the best in food and vegetables. Sweet potato contains mucin, which helps to keep the elasticity of blood vessel wall and prevent arteriosclerosis, and also has a good lubricating effect on respiratory and digestive system, joint cavity and serous cavity. Sweet potato is an alkaline food, rich in elements such as potassium and sodium, while rice, noodles, meat and eggs are acidic foods. So sweet potatoes can be eaten with these foods, which helps to maintain the acid-base balance of the human body. Sweet potato is rich in plant fiber, which can increase the volume of feces, has good water absorption, helps feces to be excreted in time, and can prevent constipation and intestinal diseases.

Because the starch granules of sweet potato are large, it stimulates the secretion of gastric acid after entering the gastrointestinal tract of human body, producing a large amount of carbon dioxide gas, which can cause abdominal distension, burping and acid water spitting, so it should be steamed before eating. People with more gastric acid secretion should use it with caution.