Acta Scientiarum Polonorum Technologia Alimentaria

Background: Polycystic ovary syndrome (PCOS) is a common condition that affects up to 15% of reproductive-aged women. Recently, ketogenic diet (KD) has gained popularity in treatment PCOS. The aim of this meta-analysis was to assess the evidence from randomized controlled trials (RCTs) for the effects of KD on changes in body weight, glycaemic, lipid parameters and reproductive hormone levels among PCOS women.

Materials and methods: The PubMed, Cochrane Library, and Web of Science databases were searched to retrieve RCTs on the effect of KD (very low caloric ketogenic diet: VLCKD and low caloric ketogenic diet: LCKD) on anthropometric, metabolic and hormonal parameters in women with PCOS through to March 2025. Five RCTs involving 313 patients with PCOS were included in this systematic review.

Results: Three studies indicated changes in anthropometric, metabolic, and hormonal parameters after a VLCKD compared to a hypocaloric Mediterranean diet, with two RCTs comparing an LCKD to a typical diet. The pooled findings indicated that various anthropometric (body weight index BMI and waist circumference WC), metabolic (fasting plasma glucose FPG, insulin, HOMA-IR) and hormonal (luteinizing hormone LH, sex hormone-binding globulin SHBG) parameters significantly decreased following a KD intervention. Furthermore, subgroup analyses revealed a VLCKD significantly improved BMI, FPG, and, cholesterol TC, low density cholesterol LDL, high density cholesterol HDL, LH, while an LCKD significantly improved LDL, HDL and LH.

Conclusion: Therefore, a VLCKD is recommended for improving some anthropometric and metabolic parameters in women with PCOS but future larger and longer RCTs are required to assess the safety and effects of KD in terms of weight loss, cardiometabolic and hormonal benefits in PCOS women.

PROSPERO registration no.CRD 42024503878.