New mothers may research alternative ways to melt their postpartum weight while breastfeeding without causing any harm to them or their baby. Intermittent fasting is one such method. However, fasting may affect breast milk supply and composition, and mothers should be aware of it before attempting intermittent fasting.
Read on to know about intermittent fasting while nursing and whether or not it’s safe for the mother and the baby.
What Is Intermittent Fasting?
Intermittent fasting is an eating pattern where you eat at specific times and fast for specific periods. Since meals interject your fasting, it is called intermittent fasting (1). Most intermittent fasting patterns have no restriction on water intake, although caloric drinks, such as drinks with sugar, milk, and other beverages with calories, are restricted and should be consumed with meals.
Research indicates that intermittent fasting may benefit overall health since it encourages the body to tap into its fat reserves due to fewer calories received from food (2). Therefore, it is quite popular among individuals who desire to lose weight, including lactating mothers who wish to lose the extra weight they gained over pregnancy.
There are various intermittent fasting patterns, including those where you do not fast entirely and only restrict your calorie intake significantly. Below are some of the most common ones (3).
- The 16/8 technique entails fasting for 16 hours per day and curtailing the daily consumption window to eight hours.
- The 5:2 diet involves eating about 500 calories a day for two days a week and have a regular diet for the remaining five days.
- Alternate day fasting involves reducing your calorie intake to 500 calories every alternate day.
- A 24-hour fast is when you fast for a day or 24 hours for any two non-consecutive days a week.
Is Intermittent Fasting Safe For The Mother?
There is insufficient research to conclude the benefits or detrimental effects of intermittent fasting on the breastfeeding mother. The type of intermittent fasting pattern chosen may determine the effect of intermittent fasting on the mother’s health, her breast milk production, and the breast milk supply (4).
According to a few studies, below are some of the potential side effects of intermittent fasting on lactating mothers (5).
- 24-hour fasting without water intake may bring an imbalance in the concentration of electrolytes in the milk with a drop in the milk’s potassium levels.
- 24-hour fasting may affect the fat content of the milk, and there could be a drop in the number of triglycerides.
- Some mothers may be at an increased risk of hypoglycemia (low blood sugar), which may interfere with their ability to breastfeed their baby.
- Some mothers may notice a drop in their breast milk supply.
Is Maternal Intermittent Fasting Safe For Babies?
There is inadequate research into the effects of maternal intermittent fasting on breastfeeding babies. The effects may vary based on the type of intermittent fasting pattern chosen and the baby’s health.
According to a few studies, below are some of the potential side effects of maternal intermittent fasting on breastfeeding babies (6).
- A decline in breast milk’s nutritional composition due to a 24-hour fast may cause the baby to receive insufficient nutrients than the recommended daily intake.
- Fasting for several hours may reduce the concentration of micronutrients, such as zinc and magnesium, in the milk. These micronutrients are vital for several functions, such as maintaining immunity.
- Frequent intermittent fasting may affect the milk supply, affecting the baby’s regular feeding pattern. The baby may demand more milk at odd times since they receive insufficient milk during each feed.
Intermittent Fasting Factors That Could Affect Breastfeeding
Since there is no conclusive evidence, the effects of maternal intermittent fasting on the mother and baby may depend on various factors. Below are the key factors that may influence how you or your baby reacts to intermittent fasting.
- Period of intermittent fasting. A 24-hour fast is most likely to have side effects for you and your baby than limiting calorie intake to 500 calories twice a week.
- Extent of dietary restrictions. Intermittent fasting with restricted water intake is more likely to affect breast milk composition and supply.
- Type of food eaten. If you eat dietary supplements or a balanced meal, it may replenish all the nutrients lost during fasting, causing little to no effect on your breast milk composition.
- Overall health of the mother. If you are already losing postpartum weight through breastfeeding and exercise, intermittent fasting may not be very helpful.
- Presence of health problems in the mother or baby. Intermittent fasting may not be healthy for you or your baby if any of you have a health condition. For instance, if your baby has iron-deficiency anemia, intermittent fasting may not be advisable since you will need to maintain adequate iron levels in the breast milk.
- Sensitivity of the baby to milk supply or quality. Some babies could be more sensitive to the milk’s composition and supply, causing them to be easily affected by maternal intermittent fasting.
- Exclusively breastfed or formula-fed baby. Exclusively breastfed babies may be more easily affected by changes in milk composition due to intermittent fasting than babies who also receive nourishment from formula.
- Medications taken by mother or baby. Some medicines may affect breast milk composition, and when coupled with intermittent fasting, it could significantly change its nutrient content. Babies on medication may require frequent feeding, which may not be possible if the mother is fasting intermittently.
How To Safely Fast During Lactation?
Healthcare experts recommend that you consult a doctor before trying any form of intermittent fasting during lactation (7). Intermittent fasting is usually not recommended for lactating mothers, but you may try it under a doctor’s supervision (8).
Below are some points to keep in mind before and during intermittent fasting while breastfeeding.
- Consider your baby’s age and whether they are exclusively breastfed. Breast milk is the only source of nutrients and fluids for exclusively breastfed infants younger than six months. If that is the case with your baby, consider waiting until they are six months old to begin intermittent fasting.
- Pick the least intense type of intermittent fasting, such as the 16/8 technique or 5:2 diet, where you may still be able to eat adequate food during your waking hours.
- Do not pick any intermittent fasting technique where you may have to restrict water intake. Inadequate water intake may negatively affect your body’s water content, affecting your breast milk supply eventually.
- Eat balanced meals with adequate nutrients to maintain the nutritional composition of your breast milk.
- You must continue to take any supplements prescribed by the doctor and should not cut them down during fasting.
- Some medications may require you to not be empty stomach for too long. If you are on any medication, discuss your intermittent fasting with the doctor.
- If you notice any changes in the baby’s feeding patterns, growth, diaper-soiling patterns, and overall health, stop intermittent fasting immediately.
In most cases, breastfeeding alone may help you lose postpartum weight without the need for intermittent fasting. There are also several ways to lose postpartum weight naturally without fasting, and you may read about it here.
Intermittent fasting holds many benefits, but it may not necessarily be applicable for lactating mothers. A healthy balanced diet during lactation is vital to prevent any nutritional deficiencies in your body and maintain your breast milk’s nutritional composition. If you still wish to try intermittent fasting while breastfeeding, consider your health, baby’s health, and baby’s age and discuss it with a doctor before you begin.
2. What is intermittent fasting?; Intermountain Healthcare
3. Intermittent Fasting: 4 Different Types Explained; Cleveland Clinic
4. Alessandra N. Bazzano et al., How do pregnant and lactating women, and young children, experience religious food restriction at the community level?; U.S. National Library of Medicine
5. Deena R. Zimmerman et al., Effect of a 24+ Hour Fast on Breast Milk Composition; Pennsylvania State University
6. Neslisah Rakicioglu et al., The effect of Ramadan on maternal nutrition and composition of breast milk; U.S. National Library of Medicine
7. Jane Racey Gleeson, Intermittent Fasting: Is it Right for You?; University of Michigan
8. Diet Review: Intermittent Fasting for Weight Loss; Harvard T.H. Chan School of Public Health