53. Healthy Habits
Deios 4:1
Maintaining a healthy and fit body is part of a person’s service of God because one cannot pursue knowledge of his Creator when he is sick. Therefore, a person must avoid things that harm the body and he must accustom himself to things that are healthy and make the body strong. Specifically, a person should only eat when he is hungry and drink when he is thirsty. One should not delay relieving his bladder or bowels, even for a moment. Rather, when he feels the need, he should attend to it right away.
Deios 4:2
A person should not eat until he is full. Rather, he should only eat until he is about three-quarters full. One should drink only a little water during a meal, mixed with wine. When food begins to be digested in one’s intestines, he should drink what is necessary. One should not drink too much water, even when his food has been digested. One should not eat until he has made sure that he doesn’t need to relieve himself. Before eating, one should take a walk or engage in some other exercise to raise his body temperature. One should engage in a sweat-inducing form of exercise each morning, after which he should rest a little and then eat. Bathing in hot water after exercise is a good thing to do. One should wait for a little while and then eat.
Editor’s note: The Rambam lived in the 12th century and his medical advice incorporates the best knowledge of his day. Consult your rabbi with any questions involving practical application of these halachos.