A Pilot Randomized Control Trial Evaluating the Feasibility of a 12-Week Mediterranean Diet Intervention Without Caloric Restriction in Women with Polycystic Ovary Syndrome

<b>Background/Objectives</b>: Women with Polycystic Ovary Syndrome (PCOS) often report difficulties adhering to dietary interventions due to a combination of physiological and psychological barriers. Therefore, this study explores the feasibility of a Mediterranean diet (MedDiet) intervention as an effective and acceptable dietary approach for managing PCOS. <b>Methods</b>: Women with PCOS and a BMI ≥ 25 kg/m², aged 18-45 years were randomized to an ad libitum MedDiet or Healthy Eating (HE) diet (control). The 12-week intervention incorporated fortnightly, personalized dietary consultations and tailored resources. Primary outcomes were measures of feasibility, including recruitment metrics, data collection methods, and intervention adherence. Acceptability was examined using semi-structured interviews and surveys for those randomized to the MedDiet. <b>Results</b>: Study promotion resulted in <i>n =</i> 380 interested individuals; a total of <i>n</i> = 26 were randomized to either a MedDiet (<i>n</i> = 12) or HE (<i>n</i> = 14) group. Data collection was mostly appropriate as demonstrated by the collection of 100% of anthropometric and biochemical data; however, only 69% of the 4-day food records were returned. Participants reported the intervention was acceptable, and adherence was enhanced through individualized counselling and the provision of practical resources. At week 12, adherence was significantly greater in the MedDiet group compared to HE (8.1 ± 2.4 vs. 4.6 ± 1.0; <i>p</i> = 0.002). Adherence significantly improved from baseline to week 12 in both groups (MedDiet: 3.67 ± 1.32; 8.11 ± 2.37; <i>p</i> ≤ 0.001; HE: 3.57 ± 1.27; 4.57 ± 0.98; <i>p</i> = 0.02). <b>Conclusions</b>: We showed that a 12-week pilot MedDiet intervention is feasible and acceptable for women with PCOS and a BMI ≥ 25 kg/m². Future investigation warrants a larger, adequately powered study which addresses challenges to recruitment, attrition and collection of dietary intake data.