I wrote about Maimonides’ medical teachings in my book Maimonides: Reason above All and gave many examples there. Maimonides was not only a great philosopher and writer on Jewish laws, he also practiced as a doctor and he wrote extensively about healthy living.

Maimonides wrote his Commentary on the Aphorisms of Hippocrates, one of his ten books on medicine, around the year 1195, close to ten years before his death in 1204. In the book, he offers his opinion as to which of Hippocrates’ aphorisms are correct and which are wrong.

The Greek Hippocrates (about 460–about 377 BCE) is the most famous of all physicians and is considered the father of medicine. Many people of his age, as well as for a long time after his death, considered medicine a part of religion, an involvement of the gods in the affairs of men. Hippocrates rejected this notion. Using observation and the best science of his time, he taught that diseases are not a divine punishment, nor are they the result of any other superstitious agent, such as demons, evil eyes, or animals such as black cats.

He gave the world the famous Hippocratic Oath, in which he emphasized the importance of medical ethics and careful physician treatment. The most famous part of the oath states that the doctor should do all that is reasonable to avoid harming the patient or treating the patient unjustly.

The most significant physician after Hippocrates was Galen (130–200 CE), who explained and developed Hippocrates’ teachings and whose authority prevailed for fourteen hundred years. Maimonides agreed with many of Hippocrates’ teachings as explained by Galen, but not all of them, as I detail in Maimonides: Reason above All.

Maimonides’ teachings

I listed dozens of good advices offered by Maimonides in that book on how to prolong life and make life as painless and enjoyable as possible. These included him stressing that everyone must exercise, even the elderly. The one that I want to emphasize here is: “Never overeat. Stop eating when your stomach is two-thirds full. Do not distend the stomach.”

Restating Maimonides’ advice in different words: he is saying that the notion that people have that they should eat until they are “full” is suicide. About half the people in the US today are killing themselves by overeating.

Scientists today have proven that Maimonides was correct. They tell us that it takes about 15 or 20 minutes for the body to register satisfaction. We need to stop eating while we still feel hungry, and we will find that in 15 to 20 minutes we will be satisfied.

To do otherwise, to leave the table feeling “full,” will result in 15 to 20 minutes that the body is overstuffed, and our bodies will rebel and kill us.

This teaching is very relevant: it is a matter of life and death.