Nutritional interventions for optimizing healthy body composition in older adults in the community: an umbrella review of systematic reviews

BackgroundOptimizing body composition for healthy aging in the community is a significant challenge. There are a number of potential interventions available for older people to support both weight gain (for those who are underweight) and weight loss (for overweight or obese people). While the benefits of weight gain for underweight people are generally clearly defined, the value of weight loss in overweight or obese people is less clear, particularly for older people. ObjectivesThis umbrella review aimed to measure the effectiveness of nutritional interventions for optimizing healthy body composition in older adults living in the community and to explore theirqualitative perceptions. Inclusion criteria Types of participantsThe participants were older adults, 60 years of age or older, living in the community. Types of interventionsThe review examinedsix types of nutritional interventions: (i) dietary programs, (ii) nutritional supplements, (iii) meal replacements, (iv) food groups, (v) food delivery support and eating behavior, and (vi) nutritional counselling or education. Types of studiesThis umbrella review considered any quantitative systematic reviews and meta-analyses of effectiveness, or qualitative systematic reviews, or a combination (i.e. comprehensive reviews). Types of outcomesThe quantitative outcome measures of body composition were: (i) nutritional status (e.g. proportion of overweight or underweight patients); (ii) fat mass (kg), (iii) lean mass or muscle mass (kg), (iv) weight (kg) or BMI (kg/m2), (v) bone mass (kg) or bone measures such as bone mineral density, and (vi) hydration status. Phenomena of interestThe phenomena of interestwere the qualitative perceptions and experiences of participants. Search strategyWe developed an iterative search strategy for nine bibliometric databases and gray literature. Methodological qualityCritical appraisal of 13 studies was conducted independently in pairs using standard Joanna Briggs Institute tools. Six medium quality and seven high quality studies were identified. Data extractionData was extracted independently in pairs from all 13 included studies using the standard Joanna Briggs Institute data extraction tool. Data summaryOnly quantitative studies of effectiveness were included. The strength of evidence assessing the effectiveness of interventionswas graded using a traffic light system (green, amber, red). An overall assessment of the quality of the evidence for each comparison was undertaken. ResultsMore systematic reviews investigating weight gain than those investigating weight loss were included. Studies onweight gain showed improved body composition for oral nutritional supplements on its own, for oral nutritional supplements in combination with resistance exercise training, and for oral nutritional supplements in combination with nutrition counselling. Studies on weight loss showed that diet in combination with exercise, diet in combination with exercise and nutrition counselling, and nutrition counselling on its own all can lead to reduced weight in older people. The outcomes of lean mass and weight/BMI were responsive to nutritional interventions, but fat mass did not vary. There were no qualitative reviews identified. ConclusionsAlthough effective interventions for weight gain and weight loss to optimize body composition of older people in the community were identified,making long term, clinically relevant changes in body composition is difficult. Multiple interventions are more effective than single interventions.