A Pilot Study on Ad Libitum Mediterranean Diet Intervention for Women with PCOS: A Mixed-Methods Exploration of Acceptability, Adherence, and Participant Lived Experience

Abstract

Background/Objectives: A healthy diet is essential for managing Polycystic Ovary Syndrome (PCOS), yet optimal recommendations remain unclear, highlighting the need to explore alternative lifestyle interventions. The Mediterranean diet (MedDiet) supports cardiometabolic health; however, challenges with adherence within this population are unknown. This study examines the acceptability and experiences of an ad libitum MedDiet in women with PCOS, offering recommendations for implementation. Methods: A 12-week MedDiet intervention was conducted with women aged 18-45 years, diagnosed with PCOS and a BMI ≥ 25 kg/m² (n = 12). Adherence was assessed using the Mediterranean Diet Adherence Screener. Surveys and semi-structured interviews, guided by the Capability, Opportunity, Motivation-Behaviour (COM-B) model, explored participants' experiences. Thematic analysis identified barriers and facilitators, which were mapped to the COM-B and Theoretical Domains Framework (TDF), with all findings subsequently aligned with the Behaviour Change Wheel to inform implementation strategies. Results: MedDiet adherence significantly improved from baseline to week 12 (Baseline: 4.1 ± 1.8; week 12: 8.3 ± 2.3; p = 0.001), alongside increases in knowledge (p = 0.004), cooking confidence (p = 0.01), and time management (p = 0.01). Adherence factors were mapped to 12 of the 14 TDF domains. Key facilitators included health benefits, reduced weight pressure, educational resources, and simple guidelines. Barriers involved organisation, food availability, and external influences. Effective implementation should integrate MedDiet education, behaviour change support, practical resources, and professional training for nutrition professionals and healthcare providers to support referrals and weight-neutral dietary management. Conclusions: A short-term ad libitum MedDiet is acceptable for women with PCOS. Strategies for patients and healthcare providers, aligned with the intervention functions of education, training, and enablement, are key to supporting adherence.

Keywords: COM-B; Mediterranean diet; PCOS; behaviour change wheel; dietary implementation; lived experience.

Figure 1

Flow diagram of participant recruitment.

Figure 2

Mean change in Mediterranean Diet adherence scores (MEDAS) for the MedDiet group from baseline to week 12. * Statistical significance p ≤ 0.05.

Figure 3

Participants’ self-reported median ratings of confidence and ability toward COM-B elements affecting MedDiet adherence from baseline to week 12. * Statistical significance p ≤ 0.05. Rating scale 1 none, 2 low, 3 neutral, 4 high, and 5 very high.

Figure 4

Participant assessment of intervention resources and delivery.

Figure 5

Integration of qualitative themes and quantitative data analysis, with a summary of recommended strategies for dietary implementation, mapped to the COM-B model. The inner circle represents areas where qualitative and quantitative findings align, while the surrounding sections depict themes derived solely from qualitative data.