Fasting and women's health

This page is general information, not medical advice, and it is not telling anyone what to observe. It exists because the observances that are hardest on the body are disproportionately the ones kept by women, and that deserves specific rather than generic information.

Pregnancy

A long dry fast in pregnancy carries real risk: dehydration reduces amniotic fluid volume and can trigger contractions, and fluid requirements are higher throughout. The observances of most concern are the full-form dry fasts — Karva Chauth, Nirjala Ekadashi, Hartalika Teej, Chhath, and a long summer Ramzan day.

Every tradition here provides for this. Islamic law exempts pregnant women with recognised provisions; Hindu families routinely accept a partial or modified observance and elders often actively advise it; Jain guidance is given according to capacity.

The right sequence is: speak to your doctor, then to your family. In practice most families are far more accommodating than people expect, and often relieved to be asked.

Breastfeeding

Milk supply is sensitive to hydration, and a long dry fast can reduce it within a day. Energy demand while exclusively breastfeeding is substantial — several hundred kilocalories a day above baseline.

Where a fast is kept, front-loading fluid before it and rehydrating steadily afterwards helps. A noticeable drop in supply or in the baby's wet nappies is a reason to stop, not to persist.

Menstruation

Islamic practice is explicit: fasting is not kept during menstruation and the days are made up later. In many Hindu households menstruating women do not keep the vrat or participate in the puja, though practice on this varies widely and is changing in many families.

Physically, a heavy period plus a long fast is a poor combination — iron loss on top of low intake, and dizziness is more likely. Where a modified observance is available, this is a sensible time to use it.

Iron, which India is already short of

Iron deficiency anaemia is common among women in India, and vrat food is a poor source of iron — the permitted list excludes most of the reliable ones.

Symptoms overlap almost exactly with fasting symptoms: fatigue, breathlessness on stairs, dizziness, poor concentration. That means anaemia gets attributed to the fast and goes unnoticed for years.

If you feel unusually exhausted during fasts and it does not resolve afterwards, ask for a blood test rather than assuming it is the vrat. This is the most common preventable problem in this entire area.

Energy availability, training and the cycle

Sustained low energy availability — training hard while eating too little for long enough — can disrupt the menstrual cycle and, over time, bone density. A nine-day vrat will not do this on its own. Sixteen weeks of a weekly single-meal fast alongside heavy training might contribute for someone already close to the line.

A missed or lost period in someone training and fasting regularly is a medical signal, not a convenience. Get it looked at.

The long dry fasts, specifically

• Karva Chauth: 12–15 hours dry, on a working day. Sargi is where the day is decided — fluid, protein and some salt beat a purely sweet sargi.
• Hartalika Teej: about 24 hours dry, in monsoon humidity, often with a night vigil. Two stressors at once.
• Chhath: roughly 36 hours dry, with cold-water immersion at dawn and dusk. The most demanding observance covered on this site.
• Vat Savitri: a day fast in the hottest month, with an outdoor puja. Shade is the whole strategy.
• For all of these: go with someone, tell them you are fasting, and sit down at the first sign of dizziness rather than the third.

সূত্র·প্রকাশিত ব্রতের প্রথা + IFCT 2017·figures given as ranges; what is and is not sourced is set out in full on the sources page·পর্যালোচিত জুলাই 2026

Sources, with dates →