לעולם לא יאכל אדם אלא כשהוא רעב ולא ישתה אלא כשהוא צמא
Maimonides begins the fourאי chapter of his Hilkhot De’ot explaining the religious obligation to keep ourselves healthy4:1: “Maintaining a healthy and sound body is among the ways of God… one must avoid that which harms the body and accustom himself to that which is healthful and helps the body becomes stronger”.
Keeping a good health requires staying away from bad habits. The very first sensitive area to improve according to Maimonides is our eating habits.
Maimonides teach us that we should eat in moderation. Eat to live and not live to eat.
In Chapter 4, Halakha 2 Maimonides refers to overeating, in Hebrew akhila gasa, i.e., gluttony .4:2: “One should not eat until his stomach is full. Rather, [he should stop eating when] he has eaten close to three quarter’s of his full satisfaction.” In other words, it is not bad to stay a bit hungry after we are done eating. It is actually a desirable habit.
We live in a time in which B”H most of us have no problem getting food in our tables. In America, for example, the main problem related to public health is not malnutrition (=not having enough food) but overeating. Obesity has become epidemic and it is said to be the number one health hazard for millions of people.
Maimonides said this explicitly more than 800 years ago:
4:15: “Overeating (akhila gasa) is like poison to anyone’s body. It is the main source of all illness. Most illnesses which afflict a man are caused by harmful foods or by his filling his stomach and overeating, even of healthful foods. This was implied by King Solomon in his wisdom: ‘Whoever guards his mouth and his tongue, guards his soul from distress’ Proverbas, Mishle, 21:23. ‘Guards his mouth’, from eating harmful food or overeating and guards ‘his tongue’ from speaking [about things] other than his needs.”
I left for the end of this Halakha what I consider to be the most comprehensive and practical of Maimonides’ statements referring to the habit of eating.
4:1 “Do not eat unless you’re hungry”.