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Here's What You Need To Know About Trying Intermittent Fasting While Breastfeeding

by Cat Bowen

About two years ago, I was feeling really bogged down with extra weight and myriad gut health issues. I had no idea what I could do to make it better, but I'd heard a lot of my friends in the fitness community talking about intermittent fasting (IF). A few of my girlfriends were only eating during eight hours per day, and fasting the other 16. Other friends would eat normally for five days, and fast completely for two days. I tried it, and I'm a devotee. But I wonder, if I have more kids, is intermittent fasting safe while breastfeeding?

Intermittent fasting has grown in popularity over the last few years thanks in part to Dr Jason Fung MD's book The Obesity Code. In it, Fung discussed his thoughts on why we're facing such an obesity crisis. He explained that we simply eat too much, and never give our bodies time to recover. Enter fasting. However, in his follow-up book The Complete Guide to Fasting, Fung warned against the practice during pregnancy and breastfeeding, noting that the risks far outweigh any potential benefits.

La Leche League International has no official position on the practice of intermittent fasting while breastfeeding, but did note that during religious fasting, no significant changes were noticed in the milk.

There are a few types of intermittent fasting as per the literature. Alternate day fasting is the type of fasting wherein you eat normally every other day. On alternating days, you eat about 25 percent of your regular daily caloric needs. The second popular method is known colloquially as 5:2 — so named because you eat normally for 5 days per week, and eat absolutely nothing or very, very little on two days per week. The most popular type of intermittent fasting is what's known as "hour restriction." It's the type of IF that I practice. Basically, you have a window of hours in which you can eat. Typically it's either eight or 10 hours per day, and you fast for 14 or 16 hours.

Different from many styles of religious fasting, there is no restriction on water intake during your fasting hours. You can drink water, black coffee, or black tea to your heart's delight. The trick is that you don't want to take in more than 50 calories during your fasting hours. If you absolutely must have cream in your morning coffee (or vanilla soy milk as it is kissed from the gods), make sure it does not exceed that paltry number of calories.

I spoke with International Board Certified Lactation Consultant (IBCLC) Ashley Egan, a lactation counselor in New York, and she tells Romper, "If you don't have to fast for religious reasons or for medical testing, I'd advise against it. While studies have shown that women who fast for Ramadan or Yom Kippur don't necessarily see a drop in milk quality or production, it's better not to risk it at all. Also, when your blood sugar is low, you might get irritable." Breastfeeding is hard enough without getting hangry, am I right?

Harvard University agrees. On their health science blog, the team wrote that, "A systematic review of 40 studies found that intermittent fasting was effective for weight loss, with a typical loss of 7 to 11 pounds over 10 weeks," but that women who are pregnant or breastfeeding should avoid this diet. They wrote that there just isn't enough evidence as to the efficacy of this plan, and it's not worth the risk.

If you're dead set on trying IF, talk to your OB-GYN and lactation consultant or nutritionist first. It's important to have all the facts and your doctor's OK before beginning any new diet, but this is especially true when you're pregnant and breastfeeding. You might have to wait until you wean before you wait to eat.

Check out Romper's new video series, Bearing The Motherload, where disagreeing parents from different sides of an issue sit down with a mediator and talk about how to support (and not judge) each other’s parenting perspectives. New episodes air Mondays on Facebook.