"There are both countless diseases and countless causes for disease. A person is really foolish if even while he is sick and wishing he were well, he does not make some attempt to know the cause of his disease.
Overeating is the main cause of disease, and lack of exercise is the second. At mealtime, one who is careful with his health reminds himself that he will not overeat and that he will eat only pure, healthy foods in moderate amounts.
He also remembers that since undigested food creates toxins and generates diseases, he must exercise in proportion to the amount he has eaten in order to thoroughly digest his food."
Swami Kripalvanadaji (Bapuji)