Polycystic ovary syndrome affects an estimated 8 to 13 percent of women of reproductive age worldwide, and one of its most stubborn features is how difficult it makes losing weight. A new study suggests intermittent fasting could offer a practical alternative to calorie counting for managing the condition.
The study, published this spring and reported by Healthline, tracked 76 participants over six months. Researchers divided them into three groups: one following a six-hour time-restricted eating window between 1:00 and 7:00 p.m. with no calorie tracking, one following a 25 percent daily calorie restriction, and a control group with no dietary changes. Both the fasting group and the calorie-restriction group achieved significant weight loss by the end of the trial.
What set the fasting group apart was what happened to their hormone levels. Participants who followed the restricted eating window showed measurable reductions in testosterone and A1C, a blood marker used to assess diabetes risk. Those changes matter because testosterone is widely considered the driver behind many of the most disruptive PCOS symptoms, including irregular periods, excess hair growth, and acne.
"Intermittent fasting may also help lower testosterone levels in PCOS, which is important because testosterone is the culprit behind many PCOS symptoms," said Krista Varady, a professor of kinesiology and nutrition at the University of Illinois Chicago and one of the study's authors. Varady noted that losing around 5 percent of body weight can itself trigger hormonal improvements in women with the condition.
The finding is significant in part because the standard first-line treatment for PCOS is hormonal birth control, which carries its own risks. Side effects can include mood changes, reduced libido, metabolic disruption, and, for some patients, an elevated stroke risk. Researchers have been looking for non-pharmaceutical options that could reduce testosterone without those drawbacks.
Varady told Healthline that intermittent fasting may simply be easier to stick with than tracking calories or macronutrients. Many participants in the time-restricted group said at the end of the trial that they planned to keep doing it.
Kristin Kirkpatrick, a registered dietitian at the Cleveland Clinic Department of Wellness and Preventive Medicine who was not involved in the research, offered a note of caution. She said intermittent fasting may support weight loss and metabolic improvements for some people, but that dietary quality still matters. Skipping meals in a narrow window does not automatically compensate for poor food choices during the eating period.
The study's primary measure was percentage change in body weight over six months. Both active intervention groups outperformed the control, but the hormonal changes observed in the fasting group give researchers a new avenue to explore for PCOS management beyond weight loss alone. Varady said both diets also showed benefits for insulin resistance, a common feature of PCOS that raises the long-term risk of type 2 diabetes.
