Nutritional strategies can improve body composition in underweight and overweight older adults

Schultz TJ, Roupas P, Wiechula R. Nutritional interventions for optimizing healthy body composition in older adults in the community: An umbrella review of systematic reviews JBI Database System Rev Implement Rep. 2016;14:257-308.

Review question

What are the effects of nutritional strategies on improving body composition in community-dwelling older adults? How are these strategies viewed and experienced by older adults?

Background

Nutrition is a significant factor in the discussion around healthy aging. In older people, being obese, overweight, or underweight are considered important health risks. Obesity and overweight are linked to a variety of chronic illnesses, while being underweight or malnourished is linked to frailty and muscle loss. Measurements of body composition—including fat, lean mass, bone mineral density, and muscle mass—have been suggested as useful indicators of health risks and nutrition status. Many systematic reviews assessing strategies aimed at enhancing nutrition status exist, highlighting the need for an umbrella review.

How the review was done

This is an umbrella review of 13 systematic reviews and meta-analyses published between 2006 and 2014.

• Participants were community-dwelling older adults, generally aged 60 years and over. Some older adults were underweight and others were overweight.
• Participants received or engaged in one or more of the following nutritional strategies: diet, nutrition counselling, or supplements. Exercise was sometimes also included.
• Researchers measured body composition through: nutritional status (proportion of individuals who were overweight/underweight), fat mass, lean mass or muscle mass, weight or body mass index (BMI), and bone mass or bone mineral density.
• Researchers also searched for evidence around strategies such as food delivery, meal replacements, and food groups, hydration status, and the views and experiences of older adults on being exposed to the nutritional strategies.
• Results were compared to people in control groups, which included usual care, education, placebo, and less intensive strategies.

What the researchers found

None of the reviews included in the umbrella review reported on hydration status, while no reviews were identified that assessed food delivery, meal replacements, food groups, or how nutritional strategies were viewed or experienced by older adults. Overall, the umbrella review showed that several nutritional strategies worked to improve measures of body composition in underweight and overweight community-dwelling older adults aged 60 years and overs. The results were mixed depending on the type of strategy used, the outcome being looked at, and the population.

Strategies for weight gain in underweight older adults:

• Oral nutritional supplements taken on their own or in combination with resistance training increased lean mass and weight, but had no effect on fat mass. Supplements on their own also increased bone mass (specifically bone mineral density).
• Nutritional counselling alone, improved nutritional status, but had no effect on weight or BMI. However, in cases where combining nutritional counselling with oral nutritional supplements was required, an increase in weight was seen.   

Strategies for weight loss in overweight older adults:

• Diet alone did not decrease weight or impact bone mass. However, it was found that diet combined with exercise resulted in weight loss.
• Diet and exercise combined with nutritional counselling did not decrease fat mass, but did decrease weight or BMI. This combined strategy was also shown to decrease bone mineral density to a level that might be harmful in very old individuals, specifically.
• Nutritional counselling reduced weight or BMI.  

The quality of the evidence ranged from low to high depending on each outcome.  In addition to decreased bone mineral density, negative side effects such as nausea, and stomach/intestinal problems were reported in some reviews. It also appeared that strategies that had multiple components may be more beneficial.

Conclusion

In older adults aged 60 years and older, body composition can be improved in underweight individuals through nutritional strategies such as oral supplements alone or in combination with resistance training, and nutritional counselling alone or in combination with oral supplements. Meanwhile, body composition can be improved in overweight individuals though nutritional counselling, diet combined with exercise, and nutritional counselling plus diet and exercise.