Definition of Meineket
A meineket (a nursing woman) is exempt from fasting on minor fast days. There is some halachic dispute as to how to define a meineket for these purposes.
Some authorities maintain that a woman has the halachic status of meineket for 24 months postpartum and is exempt from minor fasts even if she is not breastfeeding or pumping. According to this approach, a woman more than 24 months postpartum who is still breastfeeding is not halachically a meineket, and is not automatically exempt from fasting. If she feels she will need to eat on the fast day, she should ask a specific halachic question.
Other authorities define a meineket for purposes of fasting only as a woman who is actively nursing (or pumping). According to this approach, a nursing woman remains exempt even after 24 months postpartum, but a woman who is not actively nursing is not exempt.
A woman during the first 30 days postpartum has the halachic status of yoledet. For the halachot of fasting for a yoledet, please see Pregnancy, Childbirth, and Fasting.
Minor Fasts
Three minor fast days were decreed by the sages to commemorate critical events leading up to the destruction of the First and Second Temples and the dispersion of Jews into exile. A meineket is exempt from fasting on these fasts: Tzom Gedaliah, the Tenth of Tevet, and the 17th of Tammuz.
There is a difference of opinion as to whether a meineket who feels well should try to fast even though she is not required to. The Rema seems to indicate that the custom is to fast if it is not too difficult for her. However, the Mishna Brura states that a meineket who feels any weakness should not fast.
In addition, Ta’anit Esther is observed just before Purim in commemoration of the days on which the Jews defended themselves from their enemies. A meineket does not fast on Ta’anit Esther, which is the most lenient of the communal fast days.
Major Fasts
There are two major fasts on the Jewish calendar. Unlike the other fasts, which last from dawn to dusk, these fasts are a little over 24 hours long, and their rules are more stringent.
The fast of Yom Kippur is a Torah obligation (Vayikra 16:29 and 23:27) and is the most stringent of the fast days. Tisha B’Av marks the anniversary of the actual destruction of both Temples. Therefore, its halachot are more stringent than the other rabbinically-ordained fasts, but less so than those of Yom Kippur.
There are different opinions regarding the exact circumstances under which breastfeeding women should fast on Yom Kippur and Tisha B’Av.
Many poskim, including the rabbinic supervisors of this website, rule that healthy women nursing healthy babies without problems should fast on both major fast days. However, there are minority opinions that are more lenient, and each woman should consult her own halachic authority.
Note that there are different opinions regarding Tisha B’Av nidcheh, when the fast is postponed from Shabbat to Sunday. We follow the position that a healthy woman nursing a healthy baby should attempt to fast on a Tisha B’Av nidcheh. However, the fast should be treated with greater leniency than in other years, and she may begin drinking or eating as necessary at the first sign of feeling unwell. She should recite havdala before eating or drinking anything other than water.
Medically, there has been little study to date of the effect of 24+ hour fasts on breastfeeding. The first published article showed minimal biochemical changes in the milk and a small reversible decrease in milk supply on the day following a 24-hour fast, which is consistent with the instruction that healthy women who are easily nursing healthy babies should fast.
Halacha and medicine are both case-based. Therefore, if a woman is not feeling well, or she is having difficulty breastfeeding, or the baby is very young or even mildly ill, or if there are concerns about milk supply, or psychological concerns, or any other unique difficulty, a woman should consult with her physician about fasting and about when to break a fast. It is important that the physician (even if not religious or non-Jewish) be sensitive to the seriousness of this fast and give a well-considered response. The woman should then discuss any medical concerns with a halachic authority.
Because fasting on Yom Kippur is a Torah obligation, it takes precedence over attending synagogue. A woman’s fasting on Yom Kippur even takes halachic precedence over her husband’s attending synagogue. On Tisha B’Av as well, fasting takes precedence over either spouse’s synagogue attendance.
If it will help her to keep the fast, a breastfeeding woman should plan on spending the day in bed, resting, nursing, and praying on her own.
A woman who needs to break her fast should have in mind while eating that she is fulfilling the mitzva of “v’chai bahem,“ living for the sake of Torah (and not risking life).
Shiurim (Minimum Quantities) on Yom Kippur
The prohibition against eating or drinking on Yom Kippur extends even to tiny amounts. However, the penalty for violating this prohibition applies only if a certain quantity (shiur) of food or drink is consumed. Therefore, one for whom fasting is dangerous is instructed not to fast, but in some cases can mitigate the act of eating or drinking by having less than a shiur at one time.
The shiur for drinking is half of one mouthful (measured before the fast by filling the mouth and cheeks with liquid, emptying it into a measuring cup, and halving that). If eating is necessary, a woman may eat up to 30cc at a time. Ideally, these quantities should be consumed at intervals of at least nine minutes; however, opinions vary and some authorities permit intervals as short as four minutes.
Practical tips for fasting and breastfeeding include:
- Drink plenty of fluids for a number of days before the fast.
- Consider pumping some milk a day or two before, so that you have some expressed milk to offer the baby if you are tired at the end of the fast and feel you are producing less milk.
- After the fast, breastfeed frequently, drink and rest. Your milk supply should return to normal within 1-2 days.
- Do not start giving formula at this stage. This will give your body the message that less milk is necessary, and is likely to diminish your supply. If you are concerned the baby is not getting enough, give your pumped milk.
- A baby who produces wet and dirty diapers is well nourished.
- It is more important to stay home and fast and breastfeed than to break your fast and attend synagogue. It is also more important for you to fast than for your husband to attend synagogue.
- Discussion should take place prior to the fast about family arrangements (e.g., husband staying home a few hours, hiring a babysitter) that can help make it easier.
- Before the fast, discuss with your healthcare provider and a halachic authority what circumstances would warrant breaking the fast, and (for Yom Kippur) in what circumstances this should be limited to shiurim.