Can Intermittent Fasting Help You Get Pregnant?

As exciting as this may seem, not all types of intermittent fasting are great options for everyone. Read below to learn about the different styles of intermittent fasting and if it could be beneficial for you.

What is Intermittent Fasting?

Intermittent fasting, also known as fasting or timed eating, means that you go for a certain period of time without eating or consuming calorie-containing beverages. You’re still allowed to drink water and other calorie-free beverages during the fasting period. During the eating window, you eat your usual meals and snacks. There are several types of intermittent fasting plans, but these are some of the most common ones:

• 14/10: This method of fasting means that you don’t eat for 14 hours and then consume all of your food during a 10-hour period. This method is commonly used between the hours of 9am and 7pm, though fasting schedules can be adjusted to fit your lifestyle.
• 16/8: When practicing the 16/8 method, you limit your intake of meals and snacks to an 8-hour window and fast for the remaining 16 hours. You can choose any 8-hour eating window that suits your day. The common hours adopted for the eating period are 11am to 7pm.
• 24-Hour: A 24-hour fast means that you fast from dinner to dinner or breakfast to breakfast. During this time, water, tea, black coffee, and other calorie-free beverages can and should be consumed.
• Alternate-Day: Alternate-day fasting involves fasting every other day and eating normally on the non-fasting days. As with all fasting protocols, water and other calorie-free beverages are consumed during the fasting period.
• 5:2: The 5:2 protocol, also known as the Fast Diet, involves eating regularly for five days and practicing a modified fast for the other two. For the modified fast, calories are restricted to 600 for men, and 500 for women.

How Does Intermittent Fasting Affect Fertility?

Getting pregnant involves a delicate balance of hormones, body weight, and nutrition. While intermittent fasting can offer benefits, prolonged or extreme fasting methods can disrupt hormone levels and negatively impact fertility.

For women who are overweight, excess body fat can increase inflammation, disrupt hormone balance, and lead to irregular cycles. In these cases, gentle forms of intermittent fasting may help regulate ovulation and support fertility by reducing inflammation and promoting a healthy weight. On the other hand, being underweight can also cause hormonal imbalances that interfere with conception. If your BMI is below 18.5, your body may not produce enough estrogen or progesterone, leading to irregular or even missing cycles. In these cases, fasting could exacerbate hormonal issues and make it harder to conceive.

Beyond weight, fasting can also impact cortisol levels, which play a critical role in fertility. Long fasting windows or extreme fasting schedules can significantly increase cortisol, the body’s primary stress hormone. When cortisol levels remain elevated for too long, they can suppress reproductive hormones, disrupt ovulation, lower progesterone levels needed for implantation, and increase inflammation and insulin resistance, all of which can negatively impact fertility.

Because of these effects, fasting is generally better tolerated during the follicular phase (the first half of the cycle) when estrogen is dominant and the body is naturally more insulin-sensitive. However, during the luteal phase (the second half of the cycle), prolonged fasting can lower progesterone, increase stress hormones, and potentially interfere with implantation.

How to Safely Intermittent Fast?

Although intermittent fasting can have many exciting benefits, it’s not something everyone should practice. If you’re underweight or already at your ideal weight, research has shown it can cause or worsen hormonal imbalances. These negative effects are typically more common with more intense fasting plans.

For those who could benefit from some weight loss, research suggests that reducing inflammation and achieving a healthy body weight supports fertility. GENTLE forms of intermittent fasting can be a way to reach these goals, but timing matters.

• Never fast before exercising. Exercising in a fasted state can significantly increase cortisol levels, which can negatively impact your hormones and fertility. Always eat before workouts to keep your body in balance.

• Avoid extreme fasting methods. To maintain hormonal balance, steer clear of restrictive fasting plans. The 14/10 method or even a 12-hour overnight fast can offer benefits without adding unnecessary stress.

• Time fasting around your cycle. It’s best to avoid any type of fasting during the luteal phase (the second half of your cycle), as this can disrupt progesterone production, a hormone essential for implantation and early pregnancy.

• Focus on nourishment. Once your fasting window ends, avoid extreme calorie restriction, as this can negatively impact your cycle. Instead, fuel your body with organic and grass-fed proteins and fats, organic vegetables, and some fruit.

When you do conceive, it’s best to discontinue any type of fasting. During pregnancy, your body needs steady nourishment to support optimal hormone levels and a healthy baby.

* As always, seek the advice of your physician if you have any questions regarding any specific or general medical or health condition you may have, including but not limited your diet, nutrition, supplements, exercise, diagnosis, and medication.

PMID: 33135359, 23382817, 27499591, 28106818, 34736458, 33849562