title: Dietary protein intake is associated with lean body mass in community-dwelling older adults.
abstract: Lean body mass (LBM) is important to maintain physical function during aging. We hypothesized that dietary protein intake and leisure-time physical activity are associated with LBM in community-dwelling older adults. To test the hypothesis, participants (n = 237; age, 65-92 years) did 3-day weighed food records and reported physical activity. Body composition was assessed using dual-energy x-ray absorptiometry. Protein intake was 0.98 ± 0.28 and 0.95 ± 0.29 g/kg body weight in male and female participants, respectively. Protein intake (in grams per kilogram of body weight) was associated with LBM (in kilograms); that is, the differences in LBM were 2.3 kg (P < .05) and 2.0 kg (P = .054) between the fourth vs the first and the fourth vs the second quartiles of protein intake, respectively. Only a minor part of this association was explained by increased energy intake, which follows an increased protein intake. Our study shows that dietary protein intake was positively associated with LBM in older adults with a mean protein intake higher than the current recommended daily allowance of 0.8 g/kg per day. Leisure-time physical activity, predominantly consisting of endurance type exercises, was not related to LBM in this group.
authors.affiliation: Unit for Nutrition Research, National University Hospital, Faculty of Food Science and Nutrition, University of Iceland, Reykjavik, Iceland.
authors.forename: Olof G
authors.initials: OG
authors.lastname: Geirsdottir
authors.forename: Atli
authors.initials: A
authors.lastname: Arnarson
authors.forename: Alfons
authors.initials: A
authors.lastname: Ramel
authors.forename: Palmi V
authors.initials: PV
authors.lastname: Jonsson
authors.forename: Inga
authors.initials: I
authors.lastname: Thorsdottir
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D000375:Aging; D001823:Body Composition; D001825:Body Fluid Compartments / Q000187:drug effects* / Q000378:metabolism; D004032:Diet; D015930:Diet Records; D004044:Dietary Proteins / Q000008:administration & dosage* / Q000494:pharmacology; D002149:Energy Intake; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D064167:Recommended Dietary Allowances; D012111:Residence Characteristics; D012737:Sex Factors
chemical_list: D004044:Dietary Proteins
keywords: 6-minute walk for distance; 6MWD; Aging; BMI; BW; Body composition; Cross-sectional study; Dietary proteins; LBM; Physical activity; RDA; TUG; Timed Up and Go test; body mass index; body weight; lean body mass; recommended dietary allowance