Once/Day Provision of Essential Amino Acid Enriched Meal Replacement Improves Body Composition and Physical Function in Obese Elderly

Abstract

Older, obese adults are compromised by muscle atrophy and excess adipose tissue. We have previously demonstrated that the acute ingestion of essential amino acids may augment net protein balance in the elderly. Using a double blind, randomized controlled trial, our objective was to compare an experimental meal replacement enriched with essential amino acids (EMR) compared to a commercial meal replacement (Optifast®) provided once/day (q.d.) for four weeks on body composition and physical function in older, obese participants. Twenty-seven individuals (69±5 yrs; body mass index of 32±4 kg/m) were randomly assigned to EMR (n=13) or Optifast® (n=15) supplementation. Measurements of body composition, skeletal muscle cross-sectional area (CSA), intrahepatic lipid and physical function were completed preand post-supplementation. Body mass, fat mass, and visceral fat mass were reduced with EMR but not altered with Optifast®. Thigh muscle CSA increased (\uf044 4.1 ± 1.9 cm) with EMR but not Optifast® (\uf044 -1.8 ± 6.0 cm). There was a significant increase in the distance covered during the sixminute walk test with EMR (\uf044 21±26 m) but no change in Optifast® (\uf044 22±54 m). Improvements in body composition and physical function support the efficacious use of EMR-based meal replacements in the obese elderly.