Fasting and Fertility: What You Should Know Before You Start Skipping Meals

Fertility is influenced by a variety of factors—hormones, nutrient intake, stress levels, sleep, and overall metabolic health. Fasting has been a prominent trend in the wellness world for over a decade, often praised for its potential benefits on metabolism, inflammation, and overall health.  But while fasting can offer health benefits for certain individuals, it's not a one-size-fits-all strategy—especially when it comes to fertility.

I work with individuals and couples navigating this very intersection—seeking clarity on what supports versus hinders their reproductive goals. For many of my clients, exploring strategies like fasting has sparked questions about hormone balance, cycle changes, and nutrient needs. Together, we evaluate the full picture: daily rhythms, lab markers, emotional well-being, and lifestyle habits. The goal is always the same—finding a sustainable, nourishing path forward that aligns with your body’s unique needs and the vision you have for your future family.

What Is Fasting, Exactly?

Fasting refers to voluntarily abstaining from food and/or drink for a specific period of time. Fasting may be helpful in some situations—especially when done gently and in sync with your cycle—but it’s not right for everyone.

There are several popular methods:

• Intermittent Fasting (IF): Restricting eating to a specific window of time each day (e.g., 8-hour window with 16 hours of fasting).

• Alternate-Day Fasting: Eating normally one day, then significantly reducing calories or avoiding food altogether the next.

• Time-Restricted Eating (TRE): Similar to IF but typically shorter fasting windows (e.g., 12:12 or 14:10).

• Prolonged Fasts: Fasting for more than 24 hours, often done under medical supervision.

For many, fasting may support weight loss, reduce inflammation, and improve insulin sensitivity—all factors that can positively affect reproductive health. But fasting also places physiological stress on the body, which may work against fertility in certain situations.

The Female Body and Fasting: A Delicate Balance

Unlike men, whose hormones follow a fairly consistent 24-hour rhythm, women experience monthly hormonal fluctuations that are carefully orchestrated to support ovulation and potential pregnancy. These fluctuations make the female body more sensitive to stress—especially the kind triggered by nutrient scarcity.

Low energy availability, which can happen when caloric intake doesn’t meet your body’s needs (as in prolonged fasting or excessive restriction), has been linked to disrupted ovulation, irregular periods, and hormonal imbalances. The body may interpret fasting as a sign of famine, leading to a downregulation of reproductive function in favor of survival mechanisms.

Research in animals and humans suggests that intermittent fasting can negatively affect reproductive hormones, particularly when not timed to support the menstrual cycle:

• A 2019 study in Obesity found that women following an alternate-day fasting protocol experienced decreased luteinizing hormone (LH), a hormone essential for ovulation (Klempel et al., 2012).

• Another study in Cell Metabolism (2017) showed that fasting in rodents caused a suppression of the hypothalamic-pituitary-gonadal axis, the hormonal pathway that regulates fertility (Roa et al., 2017).

That doesn’t mean fasting is always harmful—but it must be approached with nuance.

When Fasting Might Be Helpful for Fertility

In some cases, carefully timed fasting might benefit fertility—especially in individuals with insulin resistance, PCOS, or metabolic syndrome.

Polycystic Ovary Syndrome (PCOS) is a hormonal disorder often characterized by irregular ovulation, elevated androgens, and insulin resistance. Fasting can improve insulin sensitivity, reduce circulating insulin levels, and may indirectly help regulate menstrual cycles and support ovulation in people with PCOS.

One small study published in Translational Research found that time-restricted feeding improved insulin sensitivity and reduced inflammation in premenopausal women with obesity (Sutton et al., 2018). Since elevated insulin is a major driver of hormonal imbalance in PCOS, improving insulin signaling can be a game-changer.

Still, even with PCOS, the key is personalization. Some individuals may benefit from a moderate 12–14 hour fast overnight, while others might find that skipping meals leads to worsened symptoms, cravings, or cycle disruption.

What the Research Tells Us—and What It Doesn’t

The data on fasting and female fertility is still emerging. Many of the early studies were done on male participants or animal models, limiting our understanding of how fasting truly impacts female reproductive health.

Most importantly, fasting is not inherently “good” or “bad” for fertility. It depends on your individual hormone profile, menstrual cycle regularity, stress levels, nutritional intake, and more. What supports one person’s journey to pregnancy could hinder another’s.

Practical Considerations Before You Try Fasting

Fasting is a powerful tool—but like all tools, it needs to be used with care. For some, especially those with PCOS or metabolic dysfunction, strategic fasting may help rebalance hormones and support ovulation. For others, particularly those with lean body types or irregular cycles, it may do more harm than good.

If you’re considering intermittent fasting as part of your fertility plan, here are a few things to keep in mind:

1. Start with your cycle: Avoid fasting during the luteal phase (after ovulation), when your body needs more calories and nutrients to support potential implantation and early pregnancy.

2. Keep fasting windows short and consistent: A gentle 12:12 or 14:10 schedule may be better tolerated than longer fasts. Avoid extreme fasting or skipping meals entirely.

3. Don’t ignore hunger cues: Chronic hunger, irritability, dizziness, or disrupted sleep are signs your body isn’t responding well to fasting.

4. Track your cycle: If your period becomes irregular or ovulation becomes harder to detect, fasting may be interfering with your reproductive hormones.

5. Prioritize nutrient density: When you do eat, focus on blood sugar-stabilizing, nutrient-rich meals—think protein, healthy fats, and fiber-rich carbs.

6. Listen to your body: You know it best. If fasting leaves you depleted or anxious, it’s not the right time to experiment.

My Take on Fasting and Fertility

When working with clients, my philosophy centers on nourishment, not depletion. Your body thrives when it feels safe, nourished, and supported. That’s why I always emphasize sustainable strategies that work with your hormones, not against them. 

Fasting may offer benefits in specific contexts, especially when done gently and in sync with your body’s rhythms. But if you're trying to conceive, more is not always better, especially when it comes to restriction.

If you’re considering fasting, I encourage you to look at the bigger picture—your cycle, stress levels, nutrition, and emotional well-being.  If you're unsure whether fasting supports your fertility goals, consider working with one of my programs, where you can assess your cycle, hormone levels, and overall health to guide you in the right direction.

Bottom Line

From my years working alongside individuals and couples trying to conceive, I’ve seen firsthand that there’s no single formula for fertility success.  That’s why I believe in a tailored approach to reproductive health.  If you're on the path to pregnancy, the best approach is one rooted in alignment and trusting in your body’s cues. As always, what works for someone else may not work for you, and that's okay.

If you’re looking for compassionate, expert-led guidance on your fertility journey, my self-paced program—Body Literacy for Fertility—was created to help you understand your cycle, optimize your health, and take actionable steps toward pregnancy. You don’t have to navigate this alone. Start your path to pregnancy here.

References

Klempel, M. C., Kroeger, C. M., Bhutani, S., Trepanowski, J. F., & Varady, K. A. (2012). Intermittent fasting combined with calorie restriction is effective for weight loss and cardio-protection in obese women. Obesity, 20(6), 1134–1141. https://doi.org/10.1038/oby.2011.142

Roa, J., et al. (2017). Metabolic control of puberty: roles of leptin and kisspeptin. Current Opinion in Endocrinology, Diabetes and Obesity, 24(1), 62–67. https://doi.org/10.1097/MED.0000000000000301

Sutton, E. F., Beyl, R., Early, K. S., Cefalu, W. T., Ravussin, E., & Peterson, C. M. (2018). Early time-restricted feeding improves insulin sensitivity, blood pressure, and oxidative stress even without weight loss in men with prediabetes. Cell Metabolism, 27(6), 1212–1221.e3. https://doi.org/10.1016/j.cmet.2018.04.010

Trepanowski, J. F., & Bloomer, R. J. (2010). The impact of religious fasting on human health. Nutrition Journal, 9(1), 57. https://doi.org/10.1186/1475-2891-9-57

Michalakis, K., Mintziori, G., Kaprara, A., Tarlatzis, B. C., & Goulis, D. G. (2013). The complex interaction between obesity, metabolic syndrome and reproductive axis: A narrative review. Metabolism, 62(4), 457–478. https://doi.org/10.1016/j.metabol.2012.08.012