Effect of Ketogenic Diet on Weight, Metabolic, and Endocrine Parameters in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a common condition affecting women of reproductive age, characterized by a range of complex clinical symptoms. It is associated with hormonal imbalances, including abnormal gonadotropin secretion and elevated androgen levels, leading to issues such as irregular menstrual cycles, infertility, hirsutism, alopecia, and acne. Additionally, many women with PCOS experience hyperinsulinemia and insulin resistance, which heightens their metabolic risk. While various medications have been explored for PCOS management, lifestyle changes, particularly dietary modifications, are crucial. Research suggests that low-carbohydrate diets, like the ketogenic diet (KD), may positively impact PCOS symptoms. The current systematic review and meta-analysis aim to assess the effects of KD on anthropometric, metabolic, and hormonal factors in overweight or obese women with PCOS.

A research question was developed using the PICOS framework, and a literature search was conducted according to PRISMA guidelines for systematic reviews. Studies included in the review reported outcomes such as weight loss, body mass index (BMI), glucose and insulin levels,homeostasis model assessment - insulin resistance (HOMA-IR), lipid profiles, and hormonal levels (includingluteinizing hormone (LH), follicle-stimulating hormone (FSH), LH/FSH, estrogens, progesterone, anti-müllerian hormone (AMH), total-testosterone (total-T), free testosterone (free-T), sex hormone-binding globulin (SHBG), dehydroepiandrosterone sulfate (DHEAS)), as well as pregnancy rates and live births. Data were analyzed, and results were presented as standardized mean differences (SMD) with 95% confidence intervals (CI).

The outcome revealed the following:

• The review included seven studies which showed that KD led to significant weight loss (SMD 1.31 kg, 95% CI: 0.45, 2.17) and reduced BMI (SMD 1.27 kg/m², 95% CI: 0.71, 1.83). 
• There were decreases in blood glucose (SMD 1.36 mg/dL, 95% CI: 1.08, 1.64), insulin (SMD 1.15 µU/mL, 95% CI: 0.60, 1.70), and HOMA-IR (SMD 1.84, 95% CI: 0.72, 2.96).
• The lipid profile improved, with lower LDL (SMD 0.73 mg/dL, 95% CI: 0.03, 1.42) and triglycerides (SMD 1.11 mg/dL, 95% CI: 0.53, 1.68), while HDL levels showed a non-significant increase. 
• Hormonal changes included a reduction in LH (SMD 1.12 ng/dL, 95% CI: 0.39, 1.84), an increase in FSH (SMD -0.76 ng/dL, 95% CI: -1.25, -0.28), a decrease in the LH/FSH ratio (SMD 2.04, 95% CI: 1.04-3.03), a decline in testosterone levels (free-T SMD 0.57 ng/dL, 95% CI: 0.28, 0.86; total-T SMD 0.54 ng/dL, 95% CI: 0.28, 0.80), and a significant increase in SHBG (SMD 0.79, 95% CI: 1.24-0.34).
• However, data regarding estrogens, progesterone, DHEAS, and pregnancy outcomes were insufficient for comprehensive analysis.

In conclusion, KD appears to significantly improve various anthropometric, metabolic, and hormonal parameters in women with PCOS. Further research involving a larger cohort of women with PCOS could provide more insights into the effects of low glycemic index diets on this condition.

Source:Turetta C, Giannini A, Tarsitano MG, Gianfrilli D, Paoli A, Kontopantelis E, De Angelis E, Minnetti M, Poggiogalle E, Colizza A, De Vincentiis M, Laganà AS, Bogani G, Palaia I, Muzii L, Di Donato V. Impact of Ketogenic Diet on Weight, Metabolic, and Endocrine Parameters in Women with Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis. Gynecol Obstet Invest. 2025 Feb 20:1-19. doi: 10.1159/000543941. Epub ahead of print. PMID: 39978319.