How Intermittent Fasting Affects the Menstrual Cycle: A Hormone-Friendly Guide

Intermittent fasting has become a prominent and widely discussed approach in the health and wellness community. It’s not a diet in the traditional sense but more of an eating pattern that cycles between periods of eating and fasting. The idea is not so much about what you eat but when you eat it. You’re already fasting during sleep, and adding a few hours before or after can have enormous benefits for your health.

Intermittent fasting is the abstinence or limitation of calories for anywhere between 12 to 48 hours with periods of regular food intake and no restrictions. IF triggers something called “the metabolic switch,” where the body’s primary source of energy shifts from using glucose to lipids. This article will specifically discuss intermittent fasting and your menstrual cycle. Most importantly, it is absolutely crucial to approach this with mindfulness and flexibility. If you’re trying it out, pay attention to how your body responds, and don’t hesitate to make adjustments based on your unique needs and experiences.

Understanding the Menstrual Cycle

There are really only two phases to keep track of: bleeding or not bleeding. Bleeding is the most tangible, objective symptom of the cycle, which is why it is universally considered “Day One” of your cycle. It is also the part of your cycle when all your main hormones, estrogen and progesterone, are low. Assuming a cycle lasts 28 days, if you like technical terms, you can interchange bleeding/not bleeding with Follicular (Day 1-13, prepping a follicle for ovulation) and Luteal (Day 15-28, post-ovulation).

As your magnificent, healthy body sheds the inner lining of the womb/uterus, and the blood that would have helped a baby grow starts to flow, it is now gearing up all the hormones needed to release an egg from the follicle. Once ovulation happens, you’ve now entered the Luteal phase.

When you’re not bleeding, your body is preparing to release an egg from your ovary (ovulation) or working to proliferate (thicken) the wall of the uterus to create a home for a fertilized egg. Many other symptoms, like irritability, cravings, and energy levels, can be subjective, so no one defines the cycles based solely on those. Other consistent symptoms, like breast tenderness and egg-white-yolk consistency discharge, often indicate ovulation.

Basics of Intermittent Fasting

Let’s unravel the misconception that intermittent fasting (IF) is a diet—it isn’t. It is a pattern of eating and more of a lifestyle, which I personally love because it leaves room for flexibility.

What is intermittent fasting, and what are some methods? Intermittent fasting is an umbrella term for different eating patterns. The three most common patterns include:

1. 16/8 method: Fasting for 16 hours and eating during an 8-hour window.

2. 5:2 diet: Eating normally for five days and drastically reducing calorie intake for two non-consecutive days.

3. Eat-stop-eat method: 24-hour fasting once or twice a week.

Some women successfully incorporate intermittent fasting into their routines throughout the menstrual cycle.

Intermittent Fasting and Hormonal Balance

To understand the relationship between IF and hormones, we must consider the hormones involved: insulin, growth hormone, cortisol, norepinephrine, epinephrine, leptin, ghrelin, estrogen, and progesterone.

Intermittent fasting is a fantastic option for creating structure during the hormonal swings of your menstrual cycle. During the first half of your cycle, when all your hormones are low, it’s easier to fast for longer periods. As the days continue toward ovulation—the moment the LH from the pituitary gland in the brain surges, prompting a follicle to release an egg—all the hormones start to surge, and it may support you to fast less than you usually do.

The bare minimum of intermittent fasting recommended, if you choose a time-restricted method, is 13 hours. It is safe to fast for at least 13 hours a day throughout the entire menstrual cycle. Aside from the effects of IF on sex hormones, intermittent fasting has been linked to improved insulin sensitivity, reduce insulin resistance, and support for managing metabolic disorders like PCOS and type 2 diabetes, both of which can impact menstrual regularity.

Benefits of Intermittent Fasting

Intermittent fasting has been shown to have anti-inflammatory effects on the body. It may also benefit brain health by enhancing the production of brain-derived neurotrophic factor (BDNF), a protein that promotes the growth of new nerve cells. Studies show that aging-related loss of BDNF is associated with reduced synaptic plasticity, memory, and learning, as well as an increased risk of cognitive impairment and Alzheimer’s disease.

Potential Risks and Precautions

Fasting causes a type of good stress on the body. How will you know when to stop fasting? Consider stopping your fast if you develop heart palpitations, muscle loss, mood changes, hair loss, or mood swings that affect your immediate quality of life.

Hunger pangs, commonly called hunger pains, occur when your stomach is empty and starts contracting in response to the release of the hunger hormone ghrelin. There is a large difference between hunger pangs and stomach rumbling. Rumbling is a noise caused by the digestive process, often happening when there’s an accumulation of food, liquid, and gas traveling through your intestines.

Intermittent fasting is not generally recommended for pregnant or lactating women, frail older adults, or people with immunodeficiency. Nursing mothers should not fast longer than 13-hour stretches without adequate calories.

Conclusion

Intermittent fasting offers significant potential benefits but requires a mindful and personalized approach, especially for women during their menstrual cycles. Listen to your body, consult professionals if needed, and adjust your fasting routine to suit your unique needs.

Sources:

• PubMed Study

• Cleveland Clinic