Keto diet may restart, realign menstrual cycles for women with obesity

Key takeaways:

• Ketosis with or without exogenous ketone supplementation resulted in realigned or restarted menses.
• After 6 weeks, ketogenic and low-fat diets both improved weight, BMI, body composition and insulin sensitivity.

Compared with a low-fat diet, nutritional ketosis with or without exogenous ketones may positively impact self-reported menses for women, restarting or realigning menstrual cycles, according to study results published in PLOS ONE.

“It’s not a validated survey, but when we were reviewing responses, we realized we were changing the majority of these women’s cycles. Even for women who had normal menstrual cycles, their frequency changed,” Madison L. Kackley, PhD, CSCS, research scientist and lecturer in the department of kinesiology at The Ohio State University, said in a related press release. “One of our participants was 33 years old and had never had a period in her life. She had her period for the first time after being in nutritional ketosis for 5 days.”

Kackley and colleagues recruited 19 premenopausal women with overweight and obesity (mean age, 34 years; mean BMI, 32.3 kg/m²) from Columbus, Ohio, to compare the impact of a hypocaloric ketogenic diet, consisting of 75% of energy to maintain weight, supplemented with and without daily exogenous ketones. Participants received a precisely weighted and formulated ketogenic diet with either twice-daily ketone salts (n = 6) or a flavor-matched placebo (n = 7) daily for 6 weeks. Researchers compared results with an age and BMI-matched cohort of six women who received a low-fat diet with a flavor-matched placebo.

Both ketogenic diets provided approximately 40 g per day of carbohydrates, with remaining non-protein calories coming from fats, with an emphasis on monounsaturated and saturated fat sources. The low-fat diet contained 25% of energy from lipids, with less than 10% being saturated fat and less than 30 g of added oils. All participants self-reported menses fluctuations. Researchers also assessed body weight, body composition via dual-energy X-ray absorptiometry and fasting blood samples biweekly.

Both diets demonstrated clinically significant weight loss, primarily from fat mass and improved insulin sensitivity.

Overall, 30% of women in the ketogenic diet plus exogenous ketones group (P = .002) and 43% of women in the ketogenic diet alone group (P = .008) self-reported increased menses frequency and intensity after 14 days. After 28 days, another 30% and 33% of women in the ketosis with (P = .004) and without (P = .011) supplementation groups, respectively, reported menses restarted after a stall of more than 1 year.

No women in the low-fat diet group reported changes in menses.

According to the researchers, these data suggest a possible unique effect of nutritional ketosis, independent of weight loss.

“This research is incredibly important because there are so many unanswered questions for women,” Kackley said. “We’re trying to change things for women and give them some control — something we historically haven’t had over our reproductive status.”

Reference:

• Caldwell E. Keto diet, supplements may restart stalled menstruation. Ohio State New. news.osu.edu/keto-diet-supplements-may-restart-stalled-menstruation/. Published Oct. 30, 2024. Accessed Dec. 10, 2024.