The Effect of a Very-Low-Calorie Diet Versus a Moderate Energy Deficit Diet in Obese Women with Polycystic Ovary Syndrome: A Randomised Controlled Trial

In this randomized controlled trial involving 40 obese women with polycystic ovary syndrome (PCOS), a very-low-calorie diet (VLCD) was compared to a moderate energy deficit diet over 8 weeks. The VLCD group experienced significantly greater weight loss (−10.9% vs. −3.9%) and showed a trend towards a more substantial reduction in the free androgen index (FAI). Additionally, two women in the VLCD group achieved biochemical remission of PCOS. The VLCD also led to significant improvements in sex-hormone-binding globulin, fasting blood glucose, and waist-to-hip ratio. While both diets resulted in significant weight loss and metabolic improvements, the VLCD was more effective in reducing FAI, body weight, and waist circumference, although the moderate energy deficit diet was associated with better adherence and sustainability. The study highlights the potential benefits of VLCD in managing obesity and metabolic issues in women with PCOS, despite its small size and single-centre design.