Staying Healthy in Halacha

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healthyThe topic of health is discussed at great length today in medical journals and other publications. This issue does not discuss medical advice, but the obligation to preserve our health in general and in certain instances based on the writings found in the Gemorah, Rishonim and Achronim. The Rambam in particular wrote a tremendous amount of material concerning health. We will quote some of his writings.

Halachically Speaking
Volume 10 Issue 8

Authored by Moishe Dovid Lebovits
Reviewed by Rabbi Ben-zion Schiffenbauer Shlit”a
Piskei Harav Yisroel Belsky Shlit”a
Reviewed by Harav Yisroel Belsky Shlit”a

Food plays a major role in our lives. We enjoy three meals on Shabbos, Yom Tov including Melava Malka, Bar Mitzvahs, weddings, and kiddeishim. It can be difficult to maintain one’s health if he is not careful about what he eats and how much he eats. One would never think of eating non-kosher food or eating on a fast day, but we do not seem to think that the Torah requires us to control our eating to preserve our health. In addition, when learning or studying we tend to stay in one position. It is clear from discussions in the Gemorah and halacha that in the earlier days Jews were very active. We will also discuss overeating and exercising.

Watching One’s Health – Sources

There are many sources in Torah literature which discuss the importance of preserving one’s health.

The Rambam writes, “Keeping the body healthy and whole is part of the ways of Hashem, as it is impossible to understand the Will of Hashem if one is sick. Therefore, one has to be careful to distance himself from things which ruin the body.1 He should only eat when he is hungry, only drink when he is thirsty, and not wait when he has to use the facilities.”2

The Ritvah3 says one should not eat any unhealthy food. The Chinuch4 explains that one may not bring danger to himself because Hashem gave us a nefesh which resides within the body. To protect your nefesh, you are obligated to protect your body. The Be’er Hagolah5 says Hashem created the world with kindness for the purpose of doing good to His creations. If one puts himself in danger, he is implying that he does not want the good that Hashem gave him. There is no greater apikores than such a person.

The Tur says, “It is a mitzvah to watch one’s self to make sure he stays healthy in order to serve Hashem.”6

“It Doesn’t Matter What I Eat.”

Many people say that it does not make a difference what type of food they eat, as Hashem will ultimately decide how long they live. Therefore, it there is no need to choose healthy food. However, this is a wrong assumption. Although the Gemorah7 says that one does not hurt his hand without it being preordained from Hashem, one can bring pain onto himself even if Hashem did not prescribe it for him. This is illustrated by the Medrash8 says that 99% of people die before their time is up, and only 1% die on time. It is obvious that it is possible to die before the proper time.

The Sefer Chassidim9 says that a baal kas (angry person) has no life and dies before his time.

The Chovos Ha’levovos quotes10 a Gemorah11 that one should not stand in a place of danger and say a miracle will occur, because maybe it will not happen. If a miracle does happen then his merits will be decreased. This concept also applies to someone who is not careful about what he eats.

The Ma’aver Yabok12 says that one who follows his desires is killing himself and he has to give a din and cheshbon on it.

Advice From Early Sources on Digestion and Overeating

We will discuss digestion (since most of ones health depends on this, see below) and overeating in halacha. The Rambam13 says a very important rule with a healthy body: “As long as one exercises (see below) does not eat a lot (see below) and he has soft bowel movements (he is not constipated) no sickness will come upon him and his strength will be great even if he eats bad foods.”


A study of the digestive system will bring one to instant yiras shomayim. The Rambam14 and others15 say that most of the health and sickness of the body are dependent on how one digests his food. One who does it in the proper way will be a healthy person, but one who does not do it right will be a weak person and can bring himself to danger. The Kitzur Shulchan Aruch16 says digestion is good if the food is easy to digest.17 One should eat light foods before heavy foods.18 A full stomach cannot digest the food properly, because it cannot grind the food properly.19

The beginning of the digestion process takes place in the mouth, as the teeth grind the food and mix it with saliva. Therefore, one should not swallow any food without chewing it first.20 There are no mixing bowls in the stomach, so the stomach’s job is much easier if one were to chew his food properly before swallowing it. Since chewing is so important, one should refrain from talking. Aside from the danger of choking, this also prevents proper chewing. Reading also distracts one from chewing. One should not place food on his fork while he is chewing, as he will swallow his food faster if he sees food ready on his fork to be eaten.21

In order to help the digestion, one should drink a little while eating.22 The beginning of the digestion process takes about two hours, as the stomach produces certain enzymes that help break down the food. Too much fluid dilutes the enzymes, which makes digestion harder.23

One should be in a happy mood and not full of anger, fear and worry while eating.24


There is no need to quote studies on overeating. The fact is that many people are overweight because they overeat. The Rambam25 says that most sicknesses come either because one does not eat the right foods or because one eats too much even if he eats good foods. Obesity is harmful to the body: it makes it lethargic, disturbs its functions, and hampers its movements.26

The negative effect of overeating can be understood with the following: If a washing machine has too much clothing in it the clothing will not be cleaned properly. So too, when one eats too much his stomach is too full and cannot properly break down the food.27

Rabbeinu Yonah28 says that overeating causes harm.

One should eat until his stomach is a quarter full.29 The Mishnah Berurah30 says that one should eat good food which he needs for well-being, and not for pleasure. One should eat only to strengthen himself to serve Hashem.31

One is not allowed to eat like an animal and fill his stomach, and one may not recite an al hamichya after such eating.32


There are many studies about the benefits of exercise. It is very hard for a person who learns in Yeshiva all day, or for an office worker with a desk job, to walk around and do exercise. However, many doctors have said that the primary tool to prevent sickness is exercise.

Yaakov, who sat and learned Torah all day,33 was still able to wrestle with an angel and win.34 In addition, he was able to remove a large stone from the mouth of the well.35 The youth of klal Yisroel served in the army at the age of twenty.36 Some people were experts in slinging stones.37 There are other sources in Tananch which discuss certain exercises and their value (see footnote).38


Running was valued as an important military asset.39 A man from the shevet of Binyomin ran the long distance from Afek to Shiloh in one day to notify the Kohen about a certain matter.40 Running was viewed as a form of exercise during the times of the Gemorah as well as for mundane purposes. Running as a form of exercise on Shabbos is not permitted.41 However, running for non-exercise purposes is permitted.42


Walking as an exercise has been practiced by Jews from time immemorial. An average man was able to walk ten parsangs (about forty mil) in one day.43 Walking on Shabbos is permitted because it is enjoyable.44

On Shabbos

Exercising on Shabbos (if it causes sweating) is not permitted.45

As mentioned above, the Rambam46 says that if one exercises (and does not fill his stomach) he will not become sick and his strength will improve even if he eats bad foods. One who sits around and does not exercise, (or one who does not go to the facilities when he has to, or is constipated) will be sick all his life even if he eats good foods. The Rambam defines exercising as physical movement that alters respiration, resulting in deeper breathing and at a faster pace than usual.47

It would be wonderful if each Yeshiva had a room where the boys could exercise, be it either on a treadmill or a gym where they can play ball. This will not only help them be healthier, but it will help their learning as well.

Exercising Before Eating

The best thing to do before eating is to exercise a little,48 as the pasuk says b’zeyas apeicha and then tochal lechem.49 First one sweats and then he eats his bread. However, this is not always practical.

Eating Before Exercising

One should not eat and then exercise,50 because the food will not properly digest. One should wait at least two hours before exercising. The same rule applies to sleeping after eating.51 The Rambam52 says one should walk a little before a meal in order to warm up the body.


We have presented many halachic sources on staying healthy. One should not take this issue lightly. One has an obligation to do what he can in order to live a long and healthy life on this world. Although many of us sit at desk all day or learn in a seat all day, one must still find time to exercise.



  1. This is also mentioned in the Kitzur Shulchan Aruch 32:1. 

  2. Rambam Hilchos De’os 4:1. 

  3. Meseches Shavuos 27a. 

  4. Mitzvah 73. 

  5. C.M. 427:10. 

  6. O.C. 155. 

  7. Chullin 7b. 

  8. Vayikra Rabah 16:8.) that says that sickness and death are 99% negligence and 1% from shomayim. The commentaries define negligence as not keeping warm during the winter, and not caring about diet. The Gemorah ((Bava Metziah 107b. Refer to Chovas Halevovos shar habitachon 4. 

  9. 145. 

  10. Shar Habitochon 4. 

  11. Meseches Shabbos 32a. 

  12. Korbon Taanis 5:page 3 (old). 

  13. Hilchos De’os 4:14. 

  14. Rambam Hilchos De’os 4:15. 

  15. Kitzur Shulchan Aruch 32:2 

  16. 32:3. 

  17. Chicken is easier to digest than meat (Kitzur Shulchan Aruch 32:8). 

  18. Rambam Hilchos De’os 4:7, Kitzur Shulchan Aruch 32:12. 

  19. Kitzur Shulchan Aruch 32:3. 

  20. Kitzur Shulchan Aruch 32:13. Refer to Chaim Briyim K’halacha pages 100. 

  21. Chaim Briyim K’halacha pages 101-102. 

  22. Kitzur Shulchan Aruch 32:17. 

  23. Chaim Briyim K’halacha pages 108-110. 

  24. Kitzur Shulchan Aruch 32:22. 

  25. Hilchos De’os 4:15. See Kitzur Shulchan Aruch 32:3 

  26. The Life Transforming Diet page 53. 

  27. Chaim Briyim K’halacha pages 116-117. 

  28. Meseches Avos 2:12. 

  29. Rambam Hilchos De’os 4:2. Refer to Kaf Hachaim Y.D. 116:69, Shemiras Haguf V’hanefesh 26:footnote 1. 

  30. 170:45. 

  31. Refer to Jewish Observer Tishrei 5769 pages 23-25. 

  32. Elya Rabbah 170:23, see Pri Megadim M.Z. 170:10, Kaf Hachaim 72. This applies to Shabbos and Yom Tov as well (Refer to Shemiras Haguf V’hanefesh 26:footnote 3). 

  33. Bereishis 25:27. 

  34. Bereishis 32:36. 

  35. Bereishis 29:10. 

  36. Bamidbar 1:4. 

  37. Shoftim 20:16. 

  38. Refer to Zecharya 12:3, Keholes 5:11, Tehillim 24:8, Shmuel 2:1:18, Shmuel 2:2:15, see Meseches Shabbos 92a, Nedarim 38a, Kesubos 111a. 

  39. Refer to Shmuel 1:22:17, Divrei Hayomim 2:12:11, Melachim 2:11:13. 

  40. Shmuel 1:1:12. There are other instances as well were running was done in Tanach (Refer to Shmuel 2:18:14, 18:19, Melachim 1:1:5, 1:14:27, 14:28. 

  41. Tosefta Meseches Shabbos 17:16. In addition see Meseches Niddah 24b. 

  42. Shulchan Aruch 301:2. 

  43. Meseches Pesachim 93b, Yerushalmi Berochos 1:1. 

  44. Tosefta Peah 4:10, Tosefta Shabbos 16:17, Rama O.C. 301:2. 

  45. Shulchan Aruch Orach Chaim 328:42. See Mishnah Berurah 42. 

  46. Rambam Hilchos De’os 4:14-15. 

  47. See The Life Transforming Diet page 103. 

  48. Rambam Hilchos De’os 4:2, Kitzur Shulchan Aruch 32:6. 

  49. Bereishis 3:19. 

  50. Rambam Hilchos De’os 4:3. 

  51. Rambam Hilchos De’os 4:5, Kitzur Shulchan Aruch 32:6. Refer to Chaim Briyim K’halacha pages 107-108 why this is so. 

  52. Hilchos De’os 4:2, Kitzur Shulchan Aruch 32:6. 

About Moishe Dovid Lebovits

Rabbi Moshe Dovid Lebovits is a Rabbinical Administrator for Kof-K Kosher Supervision and the author of Halachically Speaking volume 1 and volume 2.

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