Study shows ketogenic diet effectively improves hormonal balance in PCOS women - Video

A transformative new study offers hope for women with Polycystic Ovary Syndrome (PCOS) struggling with weight, hormonal imbalances, and metabolic challenges. Published in the British Journal of Nutrition, researchers conducted a systematic review and meta-analysis of randomized clinical trials (RCTs) examining the very low-carbohydrate ketogenic diet (VLCKD) and its effects on anthropometric, hormonal, and metabolic outcomes in over 800 women with PCOS across multiple countries.

PCOS affects roughly one in ten women of reproductive age and is closely linked to insulin resistance, weight gain, and chronic low-grade inflammation, resulting in irregular cycles, fertility issues, and enhanced cardiometabolic risks. Since modest weight loss can normalize menstrual function and improve fertility, dietary interventions remain vital but often hard to sustain. VLCKD, which triggers nutritional ketosis and reduces insulin and visceral fat, may offer a practical solution.

Following PRISMA guidelines and a PROSPERO-registered protocol, the team searched global databases for RCTs up to July 2025, selecting studies involving adult women with PCOS on a VLCKD. Outcomes assessed included weight, BMI, waist circumference, fat mass, waist-to-hip ratio, key reproductive hormones (free and total testosterone, SHBG, LH, FSH, LH/FSH ratio), and metabolic markers like fasting glucose, insulin, insulin resistance (HOMA-IR), and lipid profiles.

Meta-analyses using random-effects models revealed significant reductions in body weight (~9.6 kg), waist circumference (~7.7 cm), fat body mass (~7.4 kg), and BMI (~3.5 kg/m²). Hormonal shifts indicated decreased free and total testosterone, lowered LH and LH/FSH ratio, and increased SHBG, which collectively suggest reduced hyperandrogenism and enhanced ovulatory potential. Metabolic control improved with lower fasting glucose and insulin levels and reduced insulin resistance. Triglycerides decreased; however, changes in LDL, HDL, and total cholesterol were inconsistent.

Despite moderate evidence certainty and heterogeneous trial designs — including varied caloric intakes and durations (4 to 24 weeks) — results consistently support VLCKD as an effective dietary approach to alleviate PCOS symptoms and improve cardiometabolic health. However, larger, longer-term studies are necessary to ascertain safety, adherence, and benefits across PCOS phenotypes, as well as direct comparisons with other diets.

This pioneering research charts a promising path for managing PCOS through targeted nutritional ketosis, with potential to improve fertility, metabolic function, and quality of life for millions affected worldwide.

REFERENCE: Tosatti, J. A. G., Magalhães, F. M. V., and Gomes, K. B. (2025). Effects of the very low-carbohydrate ketogenic diet in women with Polycystic Ovary Syndrome: a systematic review with meta-analysis of clinical trials. British Journal of Nutrition. DOI: 10.1017/S0007114525105692 https://www.cambridge.org/core/journals/british-journal-of-nutrition/article/effects-of-the-very-lowcarbohydrate-ketogenic-diet-in-women-with-polycystic-ovary-syndrome-a-systematic-review-with-metaanalysis-of-clinical-trials/A99D5670AC6F774E4531D143A4DB6395