Provision of a daily high protein and high energy meal: Effects on the physical and psychological wellbeing of community-dwelling, malnourished older adults; a randomised crossover trial.

Objectives: To determine whether daily provision of a high protein, high energy meal for 12-weeks to under-nourished older adults living independently in the community can improve physical, physiological, and psychological outcomes.

Design: A randomised crossover trial.

Setting: Participant homes within a 15-mile radius to meal supplier; Dartmoor Community Kitchen Hub.

Participants: Fifty-six community dwelling older adults (82 ± 7 years, 70% female) were randomised (stratified for baseline mini nutritional assessment (MNA) score and cohabiting or living alone) to receive 12-weeks of meal provision followed by 12-weeks no intervention (meals first group, n = 28), or, 12-weeks without intervention followed by 12-weeks of meal provision intervention (meals second group, n = 28).

Intervention: A daily high protein and high energy home-delivered meal for 12-weeks. Each meal contained >50% daily protein requirements (0.6 g kg^-1 of the recommended 1.2 g kg^-1.day^-1, ∼42 g protein per meal) and >40% daily energy requirements (∼715 kcal).

Measurements: Physical, physiological and psychological health (including MNA score, body composition, hand grip strength, self-esteem, and depression) were evaluated in participants' homes before and after each 12-week period (baseline, 12-weeks, and 24-weeks). The effect of meal provision was assessed by t-test then effects were combined using meta-analysis. Retention of any meal provision effect after cessation of meal delivery was quantified as change from the end of the meal intervention versus 12-weeks follow-up via paired t-test.

Results: The meal intervention significantly increased MNA score with a medium effect size (MNA: pooled Cohen's D = 0.74, p < 0.001). Energy and protein intake increased significantly during the control period where participants were asked to maintain their habitual diet in the meals second group (energy intake: increase = 252 kcal [95% CI 36-487 kcal], t(22) = 2.408, p = 0.025, protein intake: increase = 0.20 g kg^-1 [95% CI 0.04-0.357 g kg^-1], t(22) = 2.629, p = 0.015), which confounded the principle of a randomised crossover design analysis. When the control effect in those in the meals second group was removed from the analysis, the effect of the meal provision was much greater (meal provision significantly improved energy and protein intakes (311 kcal D = 0.52 (95% CI 0.22 to 0.82), p < 0.001; 0.24 g kg^-1D = 0.52 (0.19-0.81), p < 0.001, respectively), MNA score (2.6 points D = 1.14 (0.78-1.50), p < 0.001), and handgrip strength (1.5 kg D = 0.36 (0.06-0.66), p = 0.02), but did not change levels of depression or self-esteem). Twelve weeks after meal removal, the following % of the meal effect was retained: 68% for MNA score, 27% for negative mood score, 15% for daily energy intake, 6% for daily protein intake and 0% for handgrip strength.

Conclusion: Provision of high protein, high energy meals to community dwelling older adults for 12-weeks improved nutritional status and handgrip strength, indicative of reduced frailty risk. Benefits were not retained upon withdrawal of the intervention, suggesting a need for sustained interventions in this cohort to meet nutritional needs. Home-delivered meals offer a popular, and scalable intervention for community dwelling older adults to prevent malnutrition, promote health and sustain high quality independent living thus reducing the burden of ageing and frailty on health and social care systems.