Improving the dietary intake of under nourished older people in residential care homes using an energy-enriching food approach: a cluster randomised controlled study

Background To examine whether the nutritional status of aged undernourished residents in care could be improved through dietary modification to increase energy intake but not portion size. Methods A 12-week cluster randomised controlled trial was carried out in 21 residential care homes. Participants comprised undernourished residents with a body mass index (BMI) <18.5kgm(-2). All menus were analysed to evaluate nutrient provision. Energy and macronutrient intakes of undernourished residents were estimated using 3-day weighed food intake diaries. Those resident in homes randomised to intervention had their usual meals enriched with energy-dense foods to a maximum of +1673 kJ day(-1). Results Of 445 residents screened, 41 (9%) had a BMI <18.5kgm(-2) and entered the study. Despite adequate food provision, energy and macronutrient intakes were below UK dietary reference values. Mean (SEM) energy intake increased [+556 (372) kJ, P=0.154] in residents allocated to intervention but fell in those residents in control homes' receiving usual care [-151 (351) kJ, P=0.676]. Weight change [+1.3 (0.53)kg, P=0.03] was seen in intervention residents but not in controls [-0.2 (1.5)kg, P=0.536]. Between-group differences for changes in weight and energy intake were not significant (P=0.08 and 0.20, respectively). Six residents allocated to the intervention increased their BMI >18.5kgm(-2) (P=0.018). Conclusions Achieving weight gain in frail older people is difficult. These results suggest that enriching food could help address undernutrition and slow chronic weight loss. Interventions of a longer duration are needed to confirm or exclude the value of food enrichment.