title: Lean mass loss is associated with low protein intake during dietary-induced weight loss in postmenopausal women.
abstract: The health and quality-of-life implications of overweight and obesity span all ages in the United States. We investigated the association between dietary protein intake and loss of lean mass during weight loss in postmenopausal women through a retrospective analysis of a 20-week randomized, controlled diet and exercise intervention in women aged 50 to 70 years. Weight loss was achieved by differing levels of caloric restriction and exercise. The diet-only group reduced caloric intake by 2,800 kcal/week, and the exercise groups reduced caloric intake by 2,400 kcal/week and expended approximately 400 kcal/week through aerobic exercise. Total and appendicular lean mass was measured using dual energy x-ray absorptiometry. Linear regression analysis was used to examine the association between changes in lean mass and appendicular lean mass and dietary protein intake. Average weight loss was 10.8+/-4.0 kg, with an average of 32% of total weight lost as lean mass. Protein intake averaged 0.62 g/kg body weight/day (range=0.47 to 0.8 g/kg body weight/day). Participants who consumed higher amounts of dietary protein lost less lean mass and appendicular lean mass (r=0.3, P=0.01 and r=0.41, P<0.001, respectively). These associations remained significant after adjusting for intervention group and body size. Therefore, inadequate protein intake during caloric restriction may be associated with adverse body-composition changes in postmenopausal women.
authors.affiliation: Department of Internal Medicine, Section on Gerontology and Geriatric Medicine, General Clinical Research Center, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
authors.forename: Melanie J
authors.initials: MJ
authors.lastname: Bopp
authors.forename: Denise K
authors.initials: DK
authors.lastname: Houston
authors.forename: Leon
authors.initials: L
authors.lastname: Lenchik
authors.forename: Linda
authors.initials: L
authors.lastname: Easter
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Kritchevsky
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Nicklas
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000273:Adipose Tissue / Q000378:metabolism*; D000368:Aged; D001823:Body Composition / Q000187:drug effects*; D015992:Body Mass Index; D003131:Combined Modality Therapy; D004038:Diet, Reducing; D004044:Dietary Proteins / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000378:metabolism*; D009765:Obesity / Q000178:diet therapy / Q000628:therapy*; D017698:Postmenopause; D016032:Randomized Controlled Trials as Topic; D012189:Retrospective Studies; D015431:Weight Loss
chemical_list: D004044:Dietary Proteins