The art of dietotherapy roughly includes the following: firstly, investi-gating the nature of food for preventing and treating diseases. In scurvy, a disease due to vitamin C deficiency, the eating of oranges, tangerines, or other fruit rich in vitamin C is helpful. Again, garlic behaves both as a food and as a remedy for bacillary dysentery. Secondly, investigating curative effects achieved by carefully selecting certain kinds of drugs and adding them to food to complement each other. For instance rice porridge is readily digested and nutritionally beneficial to patients. However, when radix discoreae, Poria, or coix seeds are added, the porridge will have a strong anti-diarrhoea action through strengthening the spleen and improving digestion.

At present, the contents of dietotherapy are being greatly expanded. During the last few decades, cancer and cardiovascular diseases have replaced infectious diseases as the major enemy to human health. These two categories of disorders, especially cardiovascular diseases, are closely tied to food habits. Coronary heart disease, the most common cardiovascular disease, results from high blood cholesterol, which accumulates on the walls of the coronary vessels and leads to sclerosis. This process takes a long time to develop, perhaps eight to 10 years, or even as long as several decades. However, laboratory investigations reveal that signs of such pathologic changes in the coronary vessels can begin to appear during a person's 30s or even earlier. This reminds us that, so long as we pay attention to and reasonably adjust our daily food and drink, the process of arteriosclerosis can be greatly postponed or even prevented. Therefore, it is advisable, for macrobiotic purposes, to start one's healthy diet regime as early as possible to prevent the onset of obesity.