If you are cycling, you may be wondering how you can support and optimize your menstrual cycle naturally. You may be curious to learn if fasting is even healthy for you. You may also want to know, through natural means, how to reduce PMS symptoms and other symptoms related to your menstrual cycle.

Most women I work with have the same questions. The answer is yes. You can do intermittent fasting as long as you pay attention to hormone fluctuations that occur over your twenty-eight-day cycle and focus on the best foods that can support your menstrual cycle.

Excerpted from Cythia Thurlow’s new book Intermittent Fasting Transformation

Here are key guidelines:

1. If you are age thirty-five or under, adopt a flexible fasting schedule, such as every other day or a few days a week, so that you don’t risk the possibility of throwing off your menstrual cycle. This approach is in contrast to a more regular fasting schedule that can be followed by a woman north of forty and closer to perimenopause and menopause.
2. I generally advise women not to fast if they are planning on becoming pregnant. Women need a good supply of energy and nutrients, obtained from food and stored as fat, in order to support a healthy pregnancy. When the female body does not get enough quality food and undergoes other stressors like lack of sleep, reproduction and fertility can potentially be impacted. You could also lose your period temporarily, a condition called amenorrhea.
3. With intermittent fasting, the first three weeks of your cycle are the best times to fast if you have a twenty-eight-day cycle. This is the time in which your hormones are more stable, and it is a great time to decrease insulin, reduce inflammation, and activate autophagy. However, fasting during the five to seven days preceding your menstrual cycle may unknowingly lead to the depletion of nutrients and hormones necessary in the luteal phase.
   
4. Fasting is beneficial in specific circumstances. For example, women with PCOS who need to lose weight may benefit from a feeding window that is eight to twelve hours. This schedule helps balance hormones and supports weight loss. You have to be careful here, though, and not proceed if you are trying to conceive.
5. Tune in to your stress levels. If you’re under a lot of stress, postpone fasting until your situation becomes more manageable. Remember, when you fast, cortisol goes up, which can lead to imbalances in both estrogen and progesterone. It can even lead to a loss of your period. Not getting your period is a sign that your body is under too much stress to fast! To manage stress proactively.
6. Get plenty of nutrients during your feeding window—and at other times when you are not fasting. Do not focus on calorie restriction.

Also, if intermittent fasting creates nutrient deficiencies or triggers prolonged low blood sugar (hypoglycemia), this will likely impact the hypothalamus-pituitary-adrenal axis and disrupt the production of reproductive hormones. In general, if you can’t properly regulate your blood sugar, it is a sign that fasting may not be the right strategy for you. For many women, I start with ensuring that each meal is focused on protein and healthy fats. Once their blood sugar is better stabilized, they can start intermittent fasting.

Refer to the meal plans on pages 214–222. They make it easy for you to fast safely—and with very positive, hormone-balancing benefits.

Excerpted from Intermittent Fasting Transformation by Cynthia Thurlow in arrangement with Avery, a member of Penguin Group (USA) LLC, A Penguin Random House Company. Copyright © 2022, Cynthia Thurlow. Cynthia Thurlow is a nurse practitioner, CEO and founder of the Everyday Wellness Project, and international speaker.