title: Weight change and the conservation of lean mass in old age: the Health, Aging and Body Composition Study.
abstract: BACKGROUND
  Weight loss may contribute to the loss of lean mass with age.
  
  
  OBJECTIVE
  The objective was to evaluate the relation between weight loss or weight gain and changes in lean mass and fat mass in older adults.
  
  
  METHODS
  We observed changes in weight and body composition during a 4-y period in 2163 men (47%) and women (53%) aged 70-79 y in the Health, Aging and Body Composition Study cohort. Whole-body and appendicular bone-free lean mass and fat mass were measured by using dual-energy X-ray absorptiometry.
  
  
  RESULTS
  Weight loss and weight gain were common. In both weight losers and weight gainers, changes in lean mass as a percentage of initial lean mass were substantially smaller than changes in fat mass as a percentage of initial fat mass. However, the difference between the change in lean mass and that in fat mass was more pronounced with weight gain than with weight loss, especially in men. Small amounts of lean loss and fat gain were noted with weight stability. In multivariate models, weight loss was strongly associated with lean mass loss in both men and women, especially in men whose weight loss was concurrent with a hospitalization.
  
  
  CONCLUSIONS
  With weight change, a greater proportion of lean mass than of fat mass was conserved, but, especially in older men, significantly more lean mass was lost with weight loss than was gained with weight gain. These findings suggest that weight loss, even with regain, could accelerate sarcopenia in older adults.
authors.affiliation: Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15213, USA. newmana@edc.pitt.edu
authors.forename: Anne B
authors.initials: AB
authors.lastname: Newman
authors.forename: Jung Sun
authors.initials: JS
authors.lastname: Lee
authors.forename: Marjolein
authors.initials: M
authors.lastname: Visser
authors.forename: Bret H
authors.initials: BH
authors.lastname: Goodpaster
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Kritchevsky
authors.forename: Frances A
authors.initials: FA
authors.lastname: Tylavsky
authors.forename: Michael
authors.initials: M
authors.lastname: Nevitt
authors.forename: Tamara B
authors.initials: TB
authors.lastname: Harris
mesh_terms: D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000378:metabolism*; D000368:Aged; D000375:Aging / Q000502:physiology*; D001823:Body Composition / Q000502:physiology*; D001835:Body Weight / Q000502:physiology*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D015999:Multivariate Analysis; D018482:Muscle, Skeletal / Q000378:metabolism*; D015430:Weight Gain / Q000502:physiology; D015431:Weight Loss / Q000502:physiology*