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 a 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 eight weeks. The VLCD group experienced significantly greater weight loss (−10.9% vs. −3.9%) and showed a trend towards a larger reduction in the free androgen index (FAI) compared to the energy deficit group. Additionally, 18% of women in the VLCD group achieved biochemical remission of PCOS, which was not observed in the energy deficit group. The VLCD also led to significant improvements in sex-hormone-binding globulin, fasting blood glucose, and waist to hip ratio, indicating more pronounced benefits in hyperandrogenaemia, body composition, and metabolic parameters compared to the moderate energy deficit approach.