Behaviour Change Techniques Used in Mediterranean Diet Interventions for Older Adults: A Systematic Scoping Review

Mediterranean diet interventions have demonstrated positive effects in the prevention and management of several chronic conditions in older adults. Understanding the effective components of behavioural interventions is essential for long-term health behaviour change and translating evidence-based interventions into practice. The aim of this scoping review is to provide an overview of the current Mediterranean diet interventions for older adults (≥55 years) and describe the behaviour change techniques used as part of the interventions. A scoping review systematically searched Medline, Embase, CINAHL, Web of Science, Scopus, and PsycINFO from inception until August 2022. Eligible studies were randomized and non-randomized experimental studies involving a Mediterranean or anti-inflammatory diet intervention in older adults (average age > 55 years). Screening was conducted independently by two authors, with discrepancies being resolved by the senior author. Behaviour change techniques were assessed using the Behaviour Change Technique Taxonomy (version 1), which details 93 hierarchical techniques grouped into 16 categories. From 2385 articles, 31 studies were included in the final synthesis. Ten behaviour change taxonomy groupings and 19 techniques were reported across the 31 interventions. The mean number of techniques used was 5, with a range from 2 to 9. Common techniques included instruction on how to perform the behaviour (n = 31), social support (n = 24), providing information from a credible source (n = 16), information about health consequences (n = 15), and adding objects to the environment (n = 12). Although behaviour change techniques are commonly reported across interventions, the use of the Behaviour Change Technique Taxonomy for intervention development is rare, and more than 80% of the available techniques are not being utilised. Integrating behaviour change techniques in the development and reporting of nutrition interventions for older adults is essential for effectively targeting behaviours in both research and practice.