# Plant-based diets for older adults in care homes: a realist synthesis

## TL;DR

This study explores how to successfully offer plant-based meals in UK care homes for older adults, focusing on factors that influence acceptance and adherence.

## Contribution

The paper introduces a novel realist synthesis approach to design nutrition interventions for plant-based meal provision in care homes.

## Key findings

- Eight initial program theories were developed to guide plant-based meal implementation in care homes.
- Key contexts for success include motivated staff, appetizing meals, and resident desire for variety.
- Outcomes include improved resident wellbeing and increased participation in plant-based meal programs.

## Abstract

Approximately 450,000 older people reside in UK care homes, which is expected to almost double within 20 years. 3% of the UK population follow a plant-based diet (absent in all animal foods), 13% of whom are aged over 65. Plant-based meals are not mandatory to be offered in care homes, however, providing these meals could positively affect health, and ensure dignity of choice for those who already follow a plant-based diet. This review aims to explore contexts, mechanisms and outcomes that could influence the success of a plant-based meal study.

A realist synthesis of the literature was used to develop initial programme theories. The stages of this synthesis was as follows: (1) Initial scoping. (2) Search for relevant evidence (3) Selection and appraisal of documents (4) Extract data. (5) Analysis and synthesis.

From 36 articles, eight initial programme theories were constructed, taking the form of context-intervention-mechanism-outcome configurations. Contexts identified included willing, open and motivated staff, residents who desire greater variety, and meals that are appetising, easy to consume and nutritionally adequate. Intervention activities included training for chefs, nutrition education for staff and tasting sessions for residents. Cross-cutting mechanisms used across the initial programme theories included increased physical opportunity and increased psychological capability. Outcomes either related to beliefs about or participation in the study or improvements to resident wellbeing.

This realist synthesis addresses a gap in the literature relating to the provision of plant-based meals in care homes by exploring ways in which adherence and acceptability of plant-based meals can be enhanced amongst residents and staff. These findings will support the design of an empirical study where the gleaned initial programme theories will be tested in vivo. Additionally, the use of the realist synthesis presents a novel approach to designing complex nutrition interventions for specific contexts.

The online version contains supplementary material available at 10.1186/s12877-025-06927-0.