Posted on Sep 07, 2016, 6 a.m.
Older adults may need to double up on the recommended daily allowance of protein to efficiently maintain and build muscle.
Approximately 1 out of 3 adults age 50 and older suffer from sarcopenia, a progressive loss of muscle mass and strength, which can affect a person's energy and ability to perform daily activities. Consuming protein stimulates the body's cells to build protein, yet many older men and women fail to incorporate adequate sources of protein in their daily diet. Current US recommendations for daily dietary protein intake are 0.8 grams/kilogram of body weight (roughly 62 g of protein per day for a 170-pound person). IY Kim, from the University of Arkansas (Arkansas, USA), and colleagues enrolled 20 healthy adults, ages 52 to 75 years, each of whom was randomly assigned to one of four groups over a four-day test period. Two groups ate the RDA of 0.8 g/kg per day of protein: one group had even protein distribution across meals (33% of total protein at breakfast, lunch and dinner) and the other had an uneven protein distribution at meals (15% at breakfast, 20% at lunch and 65% at dinner). The other two groups ate double the RDA (1.5 g/kg day of protein) following the same even and uneven protein distribution patterns as the first two groups. The group that consumed double the RDA was supplemented with a pre-weighed milk protein concentrate (equal parts whey and casein) to ensure that they achieved daily protein goals of 1.5 g/kg day. The team observed that the distribution of protein across meals did not make a significant impact, but total amount of protein consumed did. The study authors report that: “[muscle protein fractional synthesis rate] was greater with 2RDA vs. 1RDA, regardless of distribution patterns,” submitting that older men and women may benefit from doubling up on the recommended daily allowance of protein to help maintain and build muscle.
Kim IY, Schutzler S, Schrader A, Spencer H, Kortebein P, Deutz NE, Wolfe RR, Ferrando AA.” Quantity of dietary protein intake, but not pattern of intake, affects net protein balance primarily through differences in protein synthesis in older adults.” Am J Physiol Endocrinol Metab. 2015 Jan 1;308(1):E21-8.