title: Changes in weight among a nationally representative cohort of adults aged 51 to 61, 1992 to 2000.
abstract: BACKGROUND
  Few studies have examined patterns and predictors of changes in body weight among adults in late middle age.
  
  
  METHODS
  Prospective cohort study of 7391 community-dwelling U.S. adults aged 51 to 61 years at baseline (1992), using publicly available data files from the 1992, 1994, 1996, 1998, and 2000 Health and Retirement Survey interviews. Changes in weight and body mass index (BMI) were examined for different racial/ethnic groups of men and women. The predictors of changes in body weight and BMI were determined using gender-specific linear regression.
  
  
  RESULTS
  Mean body weight and BMI increased in both genders and all ethnic groups. The mean weight gain was higher for women (1.67 kg, 95% confidence interval [CI]=1.34-1.99) than for men (1.43 kg, 95% CI=1.17-1.68). White men and women had the lowest baseline BMI but tended to gain more weight than other racial/ethnic groups. In multivariate analyses, individuals who were older or had higher baseline weight showed less weight gain. Men were less likely to gain weight if their self-reported overall health at baseline was poor compared to those in excellent health. Regular light or vigorous recreational activities and work-related activities were not associated with less weight gain. Race, education, and income were not associated with weight gain in multivariate analyses.
  
  
  CONCLUSIONS
  All population subgroups are at risk for weight gain. Public health messages should target diverse populations. The current levels of physical activity attained by this population do not appear to protect against weight gain.
authors.affiliation: Division of General Internal Medicine, Department of Medicine, Feinberg School of Medicine of Northwestern University, Chicago, Illinois, USA.
authors.forename: Xiaoxing Z
authors.initials: XZ
authors.lastname: He
authors.forename: David W
authors.initials: DW
authors.lastname: Baker
mesh_terms: D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology*; D005260:Female; D006306:Health Surveys; D006801:Humans; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology; D015999:Multivariate Analysis; D011446:Prospective Studies; D044469:Racial Groups / Q000706:statistics & numerical data; D012737:Sex Factors; D014481:United States