In Judaism, a lot of focus is on healing the world, being a good steward of the earth, caring for others, and being good to your fellow beings, but there is also a Mitzah of caring for yourself. The Mitzvah of caring for your own health is shmirat haguf — literally, “guarding the body,” which comes from “Guard yourself and guard your soul very carefully” (Deut. 4:9). The most famous of Jewish scholars Maimonides said:

“When keeping the body in health and vigor, one walks in the way of God … it is a person’s duty to avoid whatever is injurious to the body and cultivate habits conducive to health and vigor.”

A healthy mind and body allows us to perform the mitzvot and sacred duties to the best of our abilities, and to better live a Jewish life. Diet, exercise, and proper amount of sleep are all crucial to shmirat haguf, they are mentioned often in both the written and oral (Talmud) Torah. 

• Diet – “It is forbidden to live in a city that does not have a vegetable garden” (J.T. Kiddushin 4:12, 66d), which the rest of one’s diet should be comprised of grain and lean protein. 
• Exercise – Maimonides wrote, “As long as a person exercises and exerts himself … sickness does not befall him and his strength increases … But one who is idle and does not exercise … even if he eats healthy foods and maintains healthy habits, all his days will be of ailment and his strength will diminish” (“Mishneh Torah,” “De’ot” 4:14-15).
• Sleep – Physical and mental health both demand an appropriate amount of sleep to heal, clear the mind, and properly digest food. “The night was created for no other purpose than sleep” (Babylonian Talmud, Eruvin 65a).
• Avoiding harmful things – All things in moderation, unless it is immediately destructive to the body. Jews believe in moderation, things such as addiction, substance abuse, and such, are seen as maladies that need to be healed for the health of the body (chapel of the soul and holiness) and the mind. In this, shmirat haguf and the Maimonides section in the Mishnah Torah, both go hand-in-hand. 

Taking care of your health and wellbeing, going to doctors when needed and for checkups, and getting whatever care possible to keep you alive, is a sacred obligation in Judaism. Caring for yourself is as important as caring for others because if you are in poor health, you will be restricted in what you can do to help others.