Is intermittent fasting and breastfeeding safe?
If you’re interested in starting intermittent fasting while breastfeeding, the information and tips below can help you be successful in dieting AND keeping your milk supply.
I personally practiced intermittent fasting while I was breastfeeding and dropped 25 pounds and nursed my son for 21 months (read my 50 tips from my postpartum weight loss journey)! In addition, we included helpful information below from lactation consultants and relevant research studies, along with data from leading international breastfeeding groups to determine the safety behind this dieting trend for nursing mamas.
Read on to find out if this dieting practice is safe while nursing plus tips you should implement if you decide to start.
Quick Guide
What is intermittent fasting?
Intermittent fasting is simply a schedule of cycling between eating and not eating (fasting).
One of the more popular methods of fasting is called LeanGains which involves a daily 16 hour fast followed by an 8-hour window of eating.
Intermittent fasting has shown to provide numerous health benefits. However, it is most helpful in allowing people to easily create a calorie deficit and lose weight and body fat.
It’s an easy, simple, and effective way to lose weight.
Related: Zero Calorie Foods
Is intermittent fasting while breastfeeding safe?
Is it safe to practice intermittent fasting and breastfeeding? I know this was my number one concern before I started my fasting practice.
According to the La Leche League:
“…short periods of decreased caloric intake does not decrease milk supply as energy and nutrients can be drawn from the body’s stores laid down during pregnancy. Previously healthy well-nourished mothers produce normal quantities of breastmilk when faced with a short-term caloric intake reduction”
This is encouraging news for nursing moms! It essentially shows that short periods of fasting could be the perfect diet for breastfeeding moms due to the bodies ability to use fat stores to continue milk production.
Fat loss on top of fat loss from intermittent fasting while breastfeeding!
In your personal experience, you should note that the safety of fasting and breastfeeding depends on many personal factors and it’s important to speak with your doctor about the below topics that can impact your breastfeeding journey:
- Your child’s age (younger babies rely on your milk for complete nutrition)
- If you’re exclusively breastfeeding vs. feeding your child solid foods
- If you have any health issues
- The type of fasting schedule you want to use
- If you’re struggling with milk supply before fasting
In my personal experience, I spoke with a certified lactation consultant at my hospital about intermittent fasting and breastfeeding before I started my practice.
She stated that unless you are dropping your calories too low, the timing of when you eat in a 24-hour period should not technically affect your milk supply.
If you eat enough calories during each day (more on that below). It’s also important to ensure you’re eating healthy calories made up of lean protein, healthy fats, fruits, and vegetables. Mama needs healthy nutrients, too!
Intermittent Fasting and Breastfeeding Research Studies
Studies have shown that even with a lowered calorie intact or poor nutrition, a nursing mother can still provide adequate and nutritious breast milk for her baby.
- This older study shows that even general undernutrition has no effect on the quality of the quantity of breast milk. It’s important to note that general undernutrition is vastly different than daily intermittent fasting.
- This interesting study that followed women fasting during Ramadan (30 days) showed that there was no significant macronutrient change to their breast milk or to the growth of the infants. Various vitamin levels did decrease in the mothers studied. Zinc, magnesium, and potassium decreased significantly in the woman’s breastmilk.
It should be noted that fasting for Ramadan is much more strenuous than intermittent fasting for 10-16 hours each day.
Therefore, this is encouraging information to have considering the nutritional status of the women’s breastmilk was not greatly affected during their extended religious fast.
Related: How Many Calories are in a Peanut Butter Sandwich?
What if you need to fast for religious reasons?
Fasting for religious reasons will have the same effect as fasting for dieting.
- You may experience a drop in milk supply if you practice a very long religious fast or drop your calories too low.
- However, if your religious fast is intermittent, you may not experience a drop in milk supply. Of course, as long as you maintain a high enough number of calories when you resume eating.
As mentioned earlier in the study of women fasting for Ramadan, their milk supply wasn’t affected as much as the composition of their milk supply. Extended fasts do seem to have an effect on a lactating mother which is why short, intermittent fasts would be preferred.
What fasting schedule would be safest for nursing moms?
My lactation consultant did state that she would recommend a shortened feeding window every 24 hours. This would be in place of skipping entire days of eating like the popular 5:2 method or Eat Stop Eat.
This is why a 12-16 hour daily fast may be preferential for nursing moms.
In my personal experience, I fasted 12 to 16 hours each day and breastfed my son until he was 21 months old and did not see a dip in my supply.
In the studies mentioned earlier in this article, there seemed to be some changes in the vitamin makeup of breast milk after extended fasts, which is why daily intermittent fasts would be preferred rather than 24-hours or more fasts.
Will fasting affect your milk supply?
KellyMom states that a nursing mom requires between at least 1,500-1,800 calories per day to maintain adequate milk supply.
In addition, supply is also based on supply and demand and hormonal signals. Calorie intake is not the only factor that impacts your milk supply.
Still, dropping your calories lower than 1,200 calories per day may bring you a slight drop in milk supply.
Bottom line: as long as you’re eating every day and consuming at least 1,500 to 1,800 (or more!) calories, you should not experience a drop in milk supply.
Keep your calories in a healthy range to maintain milk supply! This is as much for mama’s health as for baby’s health!
Can you practice water fasting while breastfeeding?
It depends on how long you plan to practice your water fast. Traditionally, a water fast is an extended fast and can last anywhere from 24-72 hours.
Since you should not lower your daily caloric intake before approximately 1,500 calories while breastfeeding according to KellyMom, extended water fasting would not be advised during breastfeeding as it could lower your milk supply or have an impact of the vitamin makeup of your breast milk.
Can you practice intermittent fasting while breastfeeding your toddler?
It’s important to remember these 2 things:
- Intermittent fasting simply shortens your daily eating window
- It makes it easier to maintain a calorie deficit and lose weight or body fat
That said, you should be able to practice fasting while breastfeeding your toddler without any issues.
If you’re wondering whether your already limited milk supply will suffer, start slow. Start with fasting 10-12 hours every 2 or 3 days. This would simply mean either not eating after approximately 7 pm at night or simply eating breakfast closer to 10 am. I’m sure you’ve eaten a late breakfast as a mother, anyway!
Slowly add an hour to your fast over time and see how your milk supply is affected.
It’s important to note that simply shortening your feeding window shouldn’t have the effect on your milk supply — it is more important how much you eat during this window!
Will fasting affect your energy levels?
In my personal experience, after a short adjustment period, my energy levels are much higher and I credit a lot of this to intermittent fasting.
In the beginning, I did struggle with dieting headaches and crankiness. But, my body adjusted after 2-4 weeks, at which time I started seeing an improvement.
In conclusion, after a short adjustment period (which will occur when you implement any new diet), you might actually see an increase in energy levels.
Will fasting make you light-headed?
If you struggle with light-headedness when you’re hungry, you may want to speak to your doctor before beginning a fasting practice.
However, adding a bit of cream to your coffee or eating something very small under 50 calories can help. You may just have to keep an eye on how you feel as it may even out over time.
Be sure that your calories are high enough, as mentioned earlier. Intermittent fasting will aid your fat loss on its own, so there is no reason to cut your calories to a crash diet status.
In fact, it could be possible to simply shorten your feeding window to start. From there, you could then start cutting 100-200 calories as your body adjusts. Remember, we want to maintain our milk supply and lose body fat. It is a delicate balance!
How can you pass the time during the fasting period?
As a mom, are you just laughing at that question? I mean when do moms great a break, anyway? A lot of moms probably naturally practice intermittent fasting without even knowing it.
If you’re like most people, your busiest hours are likely between 6 am and 1 pm. So you may just find it easier to simply omit eating during those hours.
Weekends can prove to be harder for some people.
Try these tips on the weekend to keep your mind off your fast:
- the ritual of having your coffee or tea (this one or this one look safe for nursing mamas)
- a walk alone or with a friend
- a trip to the park with your children
- a home project
- starting a hobby
- reading a book
- organizing a room
- de-cluttering
- visiting the Farmer’s Market
- walking an indoor track and listening to a podcast
- even going shopping can help pass the time!
15 Tips for Intermittent Fasting While Nursing
The below tips will help you start your fasting practice while still safely providing breastmilk for your baby.
Milk Supply & Fasting Tips
- Take note of your milk supply before you start so you can determine if your supply is taking a hit.
- Start slow with an 11-12 hour fast a few days a week. See how it affects your milk supply and go from there.
- Breastfeeding can burn 200-700 calories per day (depending on how often you nurse), so you may not need to cuts calories quite as low to lose weight. Try shaving just a few hundred calories (the amount in your average protein bar) out of your diet each day to avoid crash dieting.
- Guzzle that water! Some experts say that water is more important than calories for making breast milk, so definitely make sure you are staying extremely hydrated!
- Nurse baby often — supply and demand are powerful triggers for milk supply.
Fasting Tips
- Stay busy during your fasting hours — keep your hands and mind occupied (not hard to do as a mom!).
- Focus on the amazing health benefits (more energy, increased longevity, better brain function, etc.).
- Track your progress regularly, if not daily to stay motivated (pictures, measurements, fit of clothing, weight, etc.).
- Play around with your schedule — like to eat at night? Try setting up your feeding window from 12 pm to 10 pm.
Take a day off if you need to! Listen to your body. - Prioritize sleep to ensure you minimize sleep-deprived sugar cravings.
- Try decaf coffee (this one looks great for nursing mamas) with a splash of half and half or cream to keep you satiated during your fast.
Diet & Exercise Fasting Tips
- Eat well during your feeding to keep yourself healthy and feeling your best.
- Have your first meal planned in advance so you don’t overeat or fill up on junk food.
- Gently ease into fasted workouts with low impact exercise like walking.
- Remember that breastfeeding and milk supply is the number 1 priority. It is a short journey, so you can always put off fasting until you’re done nursing.
Is it Safe to Fast While Breastfeeding — The Bottom Line
You should speak to your doctor first about dieting while breastfeeding, but, in general, it should be safe as long as your milk supply is well established. It’s vital that you do not drop your calories too low during your eating window. This wouldn’t be safe for you OR your milk supply!
As the research has shown, it appears that periodic fasting could be the best way for breastfeeding moms to lose weight. The additional fat loss simply from fasting coupled with the calories burned from nursing means you might not need to cut your calories quite as low to achieve fat loss. This is important when you’re concerned about maintaining a milk supply.
Plus, as busy moms do we really have time to make a healthy breakfast each day?
Happy fasting and breastfeeding, mamas!
The Best Protein Powders For Pregnancy and Breastfeeding