Fasting for Women

By Suzanne Fenske, MD, FACOG, ABOIM, MSCP

Fasting for Women

Fasting holds promises of weight loss and health, but is it right for women? And more importantly, is it right for you?

Truthfully, fasting is a complex and individual matter. Some people may see significant benefit, while others may experience downsides and hormone disruption. It also depends on the type of fasting and how much. Is it done in a health-promoting way, or is it just a guise for restriction and disordered eating behaviors?

Fasting is just a tool, but how you use it determines if it’s helpful or backfires. Today’s article will explore fasting for women, with a focus on intermittent fasting. Keep reading as we discuss:

• What is fasting?
• Types of fasting
• Potential fasting benefits
• Special considerations for women, including women in menopause and PCOS
• Who shouldn’t fast and what’s too much
• Tips for gentle fasting

What is Fasting? What is Intermittent Fasting?

Fasting is a broad term that refers to abstaining from food and drink, except water. There are some forms of fasting, such as the fasting-mimicking diet, where calorie intake is significantly restricted, but you still eat some food.

When you think of fasting, you may think of water fasting or juice cleanses, which are often marketed as quick weight loss and detox strategies. Alternatively, you may be aware of intermittent fasting, which has been a dominant nutrition trend over the last decade. While there are many types of fasting, we’ll focus on intermittent fasting in this article.

Intermittent fasting, also known as time-restricted eating, is a structured fasting strategy where one alternates periods of regular eating with fasting. Intermittent fasting involves short fasts, typically lasting 24 hours or less, practiced regularly with the goal of improving health. The time restriction creates a calorie restriction, eliminating the need to count or track food intake.

There are several types of intermittent fasting:

• Overnight fast. The most common version is 16:8: fasting for 16 hours and condensing meals into an 8-hour eating window. Some will start with a shorter fast time or extend the fast longer, up to 20 hours.

• 24-hour fasts. Typically, a person will fast for 24 hours once or twice weekly.

• Alternate-day fasting. Eat normally on one day, fast the next day, and continue with this pattern. The fast days usually involve eating about 20% of one’s caloric needs.

• 5:2 fast. Five days a week, eat normally. And two days per week, eat about 20% of your caloric needs.

• One meal per day. Eat just once daily and fast the rest of the time.

• Religious fasting. One example is the Ramadan in the Muslim tradition where you don’t eat from sunrise to sunset.

What is the Purpose of Fasting?

People may fast for spiritual reasons or as a strategy to detoxify, rest the digestive system, or lose weight. But the benefits may go deeper.

Numerous animal and human studies on intermittent fasting have demonstrated health benefits. However, most human studies use men as subjects, and there is a need for more studies, especially longer trials, focusing on women.

Nonetheless, some interesting things happen in the body when it’s in a fasted state. As fasting progresses, the body is no longer receiving new glucose, so it’s forced to release glycogen (stored glucose) from the liver and muscles. When this fuel source depletes, the body shifts to burning fat (as ketones) instead of glucose.

As fasting continues, autophagy begins. Autophagy is the housekeeping mechanism within cells; which eliminates waste and recycles molecules to enhance cellular health and function. Autophagy is associated with longevity.

A primary benefit of intermittent fasting is weight loss. Unlike other forms of dieting that promote weight loss, intermittent fasting allows for weight (fat) loss while preserving muscle. We don’t have long-term studies, but this appears to be the case in the short- to medium-term.

Other benefits may include:

• A reduction in inflammation
• Synchronization of the circadian rhythm
• Improved insulin sensitivity and blood sugar control
• Lower stress, better mood, and other mental health benefits

Women’s Health – Menopause and PCOS

Intermittent fasting benefits both premenopausal and postmenopausal women when it’s used as a therapeutic tool. However, there is no one-size-fits-all approach, and we consider many factors for each individual.

In a recently published pilot study of postmenopausal women over 8 weeks, participants followed either an intermittent fasting diet (adhering to the 16:8 method, eating only between 7 am and 3 pm) or a low-calorie diet (providing 75% of daily needs). Both groups also participated in a HIIT (high-intensity interval training) exercise program. Researchers concluded that those following the fasting and HIIT program achieved better body composition and physical performance (including heart rate and VO₂ max).

For women in perimenopause and menopause, it’s possible that well-placed fasting can help offset the metabolic changes that occur because of declining reproductive hormones.

PCOS (polycystic ovarian syndrome) is another area where fasting may be beneficial. A review of human and animal studies suggests that intermittent fasting reduces androgen levels and improves menstrual regulation in PCOS.

In a small study of women with PCOS and anovulation (no ovulation), the participants followed a 16:8 intermittent fasting schedule for 5 weeks. After the 5 weeks, 73% of participants saw an improvement in menstrual cycle regularity. Additional benefits were weight loss, body fat reduction, improved insulin sensitivity, reduced inflammation, and lower androgen levels.

Who Shouldn’t Fast

Postmenopausal women and women with PCOS are two populations where intermittent fasting may be beneficial. However, it’s important to note that when it comes to fasting, more isn’t always better. Excessive fasting can disrupt the menstrual cycle and ovulation, negatively impact hormones, and compound other stressors in one’s life.

We don’t recommend fasting for women:

• With an active eating disorder or a history of disordered eating
• Who are trying to conceive or improve fertility
• Who are pregnant or breastfeeding
• Who are recovering from surgery or an illness
• Who are underweight or have missing periods (not because of menopause)
• Who take certain medications
• Who have HPA-axis dysfunction or are under high levels of stress

Intermittent Fasting Tips for Women

The more extreme versions of intermittent fasting may be challenging to sustain over time and, in many ways, can become another crash diet. Instead, we encourage thinking of fasting as a tool in your toolkit and using it gently as you focus on building long-term health habits.

Using intermittent fasting as a way to end late-night snacking is likely beneficial, but pushing your body too far (when you already have a lot on your plate) can exacerbate symptoms and worsen hormone imbalances.

Here are some ideas for getting started with fasting, safely and gently:

• Start with a 12-hour fast overnight. Stop eating after dinner and then refrain grom eating again until breakfast. Then, you can work up to 14 hours a couple of times per week.

• Consider eating dinner earlier instead of pushing breakfast later.

• Use a protein-rich breakfast to break your fast.

• Notice how you feel. Do you experience benefits for your mood, energy, and body composition? Or, do you feel hungry, think about food all the time, and white knuckle your way through fasts?

• Remember you still need good nutrition. Load up on nutrient-dense whole foods during your eating window to ensure your body gets all of the nutrients it needs each day.

• Listen to your body, and work with TārāMD. You are the expert of you, and your body will tell you if fasting is helpful or too much. At TārāMD, we can monitor your progress through the process and help you discover the tools and habits you need to achieve your health goals.

Many fasting approaches are very restrictive and challenging to implement within a busy and active lifestyle. However, some gentle intermittent fasting when it’s a good fit, may help unlock metabolic advantages and promote healing. You don’t have to figure it out on your own; TārāMD can help.

References

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