Intermittent Fasting For Women: The Complete Guide

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Although there aren’t necessarily sex-based guidelines for intermittent fasting diets, there are some common concerns about intermittent fasting for women due to the differences in hormones and metabolism between men and women. 

Does intermittent fasting work for women? Is intermittent fasting healthy for women? More importantly, is intermittent fasting safe for women?

In this guide to intermittent fasting for women, we will discuss if intermittent fasting works for women, the benefits of intermittent fasting for women, and if there is an ideal intermittent fasting for women schedule.

We will cover: 

  • Is Intermittent Fasting Healthy for Women?
  • Does Intermittent Fasting Work for Women?
  • Benefits of Intermittent Fasting for Women

Let’s get started!

Women eating healthy food.

Is Intermittent Fasting Healthy for Women?

Intermittent fasting diets involve restricting the window of time in which you can eat.

Intermittent fasting dies are typically taken on with the goal of losing weight, although there can be other potential health benefits of fasting—such as decreased inflammation, improved cellular health by way of increased autophagy, and improvements in cardiovascular health—which spur some people to take this approach to their dietary habits.

However, concerns have been raised regarding the effects of fasting on the reproductive health of women and men. So, is intermittent fasting safe for women?

The primary concern about the safety of intermittent fasting for women stems from whether intermittent fasting for women will negatively affect levels of reproductive hormones such as estrogen and progesterone, cause menstrual irregularity and dysfunction and contribute to fertility issues. 

One animal study did find that engaging in 24-hour water fasting every other day for 12 weeks led to a significant increase in serum estradiol levels and a significant decrease in luteinizing hormone (LH) levels relative to the study rats who followed a normal dietary eating pattern. 

A woman holding up a clock pushing away a bowl of cereal.

Furthermore, the menstrual cycle was just regulated, with adverse changes resulting from the intermittent fasting diet.

However, when critically examining this study, it’s important to note that the rats were extremely young, said to be the equivalent of a nine-year-old female girl. Since this is a pre-pubertal age, and intermittent fasting is not recommended for children, the results of the study should not necessarily be applied to adult humans.

Other studies have found that when caloric intake is too low, which can occur with intermittent fasting diets for women that involve eating too infrequently or fasting too long, there can be disruptions in the secretion of gonadotropin-releasing hormone (GnRH) from the hypothalamus. 

This hormone is essential for the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which are two other important reproductive hormones. These hormones are necessary to maintain the normal functions of the ovaries, and alterations in their secretion levels or patterns can lead to menstrual cycle disruption, infertility, and bone loss.

A woman smiling eating a salad.

On the other hand, one research review looked at the effects of intermittent fasting on reproductive hormone levels in both men and women.

In terms of the effects of intermittent fasting on hormones for women, results suggested that intermittent fasting did not have an appreciable effect on estrogen, gonadotropins, or prolactin levels in women. 

The researchers noted that while these results demonstrate that intermittent fasting should be safe for women, it’s not necessarily conclusive evidence due to the limited number of high-quality studies available. 

Furthermore, there was some evidence to suggest that intermittent fasting could be particularly beneficial for women with polycystic ovarian syndrome (PCOS) who have hyperandroidism (excessive levels of male (androgen) hormones).

This is because premenopausal females with obesity who practiced intermittent fasting, particularly if they consumed their food earlier in the day, showed signs of decreased levels of androgen hormones.

A plate made into a clock with food from 10 to 6.

Does Intermittent Fasting Work for Women?

The benefits of intermittent fasting for women may not be the same as they are for men due to the differences in the hormonal profile between the sexes.

For example, although intermittent fasting has been shown to improve blood sugar regulation and insulin sensitivity in men, some studies have shown that the opposite may be true for women.

For example, one study looked at the effects of intermittent fasting for three weeks on blood sugar regulation in women and men. While blood sugar control improved in men, intermittent fasting for women led to poorer blood sugar regulation in women.

However, it’s important to note that this study used alternate-day intermittent fasting, which involves a 24-hour water fast every other day, rather than restricting the eating window to a certain number of hours per day.

This study is evidence to suggest that the intermittent fasting for women schedule of alternate day fasting may be deleterious to blood sugar regulation, but it cannot necessarily be applied to more lenient time-restricted eating intermittent fasting diet plans.

A plate made into a clock symbolizing intermittent fasting.

Benefits of Intermittent Fasting for Women

Although there may be concerns about aggressive intermittent fasting for women (namely alternate day fasting), there can also be benefits of intermittent fasting for women.

Speaking with your doctor or working with a registered dietitian or experienced nutritionist who can help you find the best diet plan—be it some sort of intermittent fasting diet pattern or otherwise—is the best approach to ensuring that you are following the most effective diet for your personal health goals and needs.

With that said, here are some of the potential benefits of intermittent fasting for women:

#1: Weight Loss

Intermittent fasting can help you decrease your caloric intake, lose weight, decrease your body fat percentage, improve your overall body composition, and decrease your waist circumference, a measure of abdominal obesity and a risk factor for metabolic syndrome.

Because intermittent fasting involves restricting the window of time that you are allowed to consume calories in a day, by default, many people find that intermittent fasting helps them ultimately decrease their daily caloric intake. If you don’t have as many hours in a day to eat, it’s typically not possible to eat as much food. 

A nutritionist explaining a plan to a client.

Furthermore, restricting your eating window can cut down on mindless eating, particularly late-night binging.

With that said, intermittent fasting will not necessarily lead to weight loss if you overeat during your eating windows. In order to achieve weight loss, you have to sustain a caloric deficit. Some people find that having a prolonged fast leads to compensatory overeating once it is finally time to eat.

#2: Decreased Blood Pressure

Hypertension, or high blood pressure, is a common health condition that affects millions of adults. Studies have found that intermittent fasting can reduce blood pressure. 

For example, one small study involving men and women with obesity found that intermittent fasting reduced blood pressure by 6% in just eight weeks.

The majority of the study participants were women, so it is reasonable to conclude that this is a benefit of intermittent fasting for women as well.

A nutritionist explains a nutritional plan.

#3: Decrease Cholesterol 

Studies have found that intermittent fasting can reduce LDL (“bad”) cholesterol and triglycerides in women. The above-referenced study found that eight weeks of intermittent fasting decreased LDL cholesterol by 25% and triglyceride levels by 32%. 

With that said, it was a very small study and only involved obese participants. A study involving adults of normal weight found that there were no benefits of intermittent fasting on LDL cholesterol or triglyceride levels.

#4: Improved Insulin Sensitivity

Although some studies have found that intermittent fasting may cause a worsening of blood sugar regulation for women, other studies have found that intermittent fasting can improve insulin levels and decrease insulin resistance in women who are overweight or obese.

For example, one study looked at the effects of six months of intermittent fasting for women who were overweight or obese on insulin sensitivity and blood sugar regulation. 

Unlike the study that involved 24-hour water fasting every other day, this version of intermittent fasting involved two days per week of a very low-calorie diet (approximately 650 calories per day) but still some caloric intake. In this way, the intermittent diet approach was less aggressive.

An empty plate, silverware, and a clock.

Ultimately, many research studies involve men or at least a participant group of both men and women. Therefore, the specific benefits of intermittent fasting for women, as well as the risks of intermittent fasting for women, are not particularly well-researched or researched in a controlled manner. 

With the currently limited compendium of research studies, it’s not possible to draw conclusions about the benefits and risks of intermittent fasting for women specifically that you can hang your hat on.

If you are interested in trying intermittent fasting, it is advisable to speak with your healthcare provider before doing so or begin with a moderate approach, such as 14/10 intermittent fasting or 16/8 intermittent fasting. 

See how your body responds, particularly if you are a pre-menopausal woman, noting any changes in your menstrual cycle, energy levels, appetite, and other biomarkers of health before progressing to a more aggressive intermittent fasting schedule.

For a complete guide on the different intermittent fasting schedules, click here!

A notebook mapping out a nutritional plan and a variety of containers of food surrounding it.
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Amber Sayer is a Fitness, Nutrition, and Wellness Writer and Editor, as well as a NASM-Certified Nutrition Coach and UESCA-certified running, endurance nutrition, and triathlon coach. She holds two Masters Degrees—one in Exercise Science and one in Prosthetics and Orthotics. As a Certified Personal Trainer and running coach for 12 years, Amber enjoys staying active and helping others do so as well. In her free time, she likes running, cycling, cooking, and tackling any type of puzzle.

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