Intermittent Fasting Boosts Weight Loss and Hormonal Balance in PCOS, Study Finds

Intermittent Fasting Shows Promise for PCOS Weight Loss and Hormonal Health

Polycystic ovary syndrome (PCOS) is a common endocrine disorder affecting 10–13% of women of reproductive age worldwide, according to the World Health Organization (WHO). Characterized by weight management challenges and hormonal imbalances, PCOS often leads to symptoms like irregular periods, insulin resistance, and elevated testosterone levels.

A groundbreaking study published in Nature Medicine suggests that intermittent fasting (IF) may offer a natural way to address these issues. Unlike traditional diets, IF focuses on when to eat rather than restricting specific foods, making it a simpler approach for some individuals.

How Intermittent Fasting Affects PCOS

The study, led by researchers including Krista Varady, PhD, professor of kinesiology and nutrition at the University of Illinois Chicago, examined 76 participants over six months. Participants were divided into three groups:

• Time-restricted eating (TRE) group: Ate all meals between 1:00–7:00 pm without calorie tracking.
• Calorie-restriction group: Reduced daily calorie intake by 25%.
• Control group: No dietary restrictions.

By the end of the study, both the TRE and calorie-restriction groups achieved significant weight loss. However, the TRE group also showed notable improvements in testosterone levels and A1C—a key marker for diabetes risk.

"Daily intermittent fasting could be an alternative to calorie counting for individuals with PCOS who are looking to lose weight. Both diets can also help with insulin resistance, which many people with PCOS have and which can put individuals at risk for diabetes."
— Krista Varady, PhD, study author

Why Hormonal Balance Matters in PCOS

Elevated testosterone is a hallmark of PCOS and contributes to symptoms like acne, hair loss, and irregular menstrual cycles. Traditional treatments, such as hormonal birth control, can help but may also cause side effects like mood changes, reduced libido, and increased stroke risk.

Varady noted in a press release: “We’re looking for other ways of lowering testosterone levels in these women. One way is through weight loss. If someone loses around 5% of their body weight, they can actually help lower testosterone levels and sidestep any kind of drug intervention.”

Expert Insights on IF for PCOS

Kristin Kirkpatrick, a registered dietitian at the Cleveland Clinic and President of KAK Consulting, highlighted the benefits of IF while emphasizing dietary quality: “Intermittent fasting may improve adherence for some individuals compared to calorie or macro tracking, which can support weight loss and metabolic improvements. However, dietary quality remains foundational.”

The study suggests that IF could be a viable, drug-free strategy for managing PCOS symptoms, particularly for those struggling with weight loss and insulin resistance.

Key Takeaways for Women with PCOS

• Intermittent fasting may aid weight loss and improve hormonal balance in PCOS.
• Time-restricted eating (eating within a 6-hour window) showed benefits similar to calorie restriction.
• Reductions in testosterone and A1C levels were observed in the IF group.
• IF could be a simpler alternative to traditional dieting for some individuals.
• Further research is needed to confirm long-term effects and optimal fasting protocols.