Developing an evidence-based and UK-adapted Mediterranean style diet for healthy eating in overweight/obesity.

Abstract

Introduction In the UK, obesity and overweight contribute to multiple non-communicable diseases (NCDs), increased individual burden and financial burdens on the National Health Service. Excess weight is a modifiable risk factor for the population. The Mediterranean Diet (MedDiet) has a long history of reducing prevalence of NCDs and may offer a more-sustainable plant-based dietary pattern. Despite this, barriers and preconceptions about MedDiet continue to hinder adoption, adherence and concordance in the UK. This research investigated the potential to contribute to a UK version of MedDiet to improve these three considerations. Methods Split into two phases, this study combined quantitative and qualitative aspects. Phase 1 was a systematic review of 4478 records with 16 found to be eligible for review. Rigorous methodology was applied using PRISMA and Cochrane Risk of Bias tool v2. Phase 2 drew on the findings from the systematic review to inform the design for online focus groups. In a semi-structured format, eligible participants (n=9) responded to the guide questions and conversation flow to explore awareness, preconceptions and barriers to adoption of the MedDiet. Iterative analyses were performed with Reflexive Thematic Analysis to develop major themes from codes and sub-themes in a post-positivist epistemology. Results The systematic review revealed a paucity of MedDiet interventions in overweight and obese, yet otherwise healthy, individuals especially outside the Mediterranean Basin. Additionally, many of the dietary modifications increased the healthiness of the diet for specific purposes. Examples of this were visible in the PREDIMED studies, where supplementary extra virgin olive oil and/or nuts were widely deployed. Non-dietary factors were broadly absent in the eligible articles, with only one behavioural study deploying a psychological model. In the focus groups, factors such as palatability, cost, conviviality and quality of produce were dominant. Three major themes were iteratively identified using verbatim transcripts of online focus groups: Challenges in Adopting the Mediterranean Diet, Cultural and Social Dimensions of Diet, and Health and Nutritional Impacts. Common barriers such as cost were raised although more unusual concepts such as conviviality and communal eating featured almost as powerfully. Conclusions Specific designs such as the ketogenic MedDiet offer promise for weight loss with the associated costs of that preprepared solution. Dietary modifications to MedDiet should be considered which increase adoption, adherence and concordance while addressing well-known barriers. Such barriers include convenience, time and cost in challenges to adoption; cultural and social aspects such as conviviality; and the health and nutritional impacts from the MedDiet. This research suggests that a modified version of the MedDiet for the UK could be developed to adapt to these factors. Future research could assess the nutritional benefits of a plant-based, seasonal and affordable MedDiet as developed by several European countries.