title: Fifteen-year longitudinal trends in walking patterns and their impact on weight change.
abstract: BACKGROUND
  Although walking is the most popular leisure-time activity for adults, few long-term, longitudinal studies have examined the association between walking, an affordable and accessible form of physical activity, and weight gain.
  
  
  OBJECTIVE
  The objective was to evaluate the association between changes in leisure-time walking and weight gain over a 15-y period.
  
  
  METHODS
  Prospective data from the Coronary Artery Risk Development in Young Adults (CARDIA) Study of 4,995 men and women aged 18-30 y at baseline (1985-1986) from 4 US cities and reexamined 2, 5, 7, 10, and 15 y later. Sex-stratified, repeated-measures, conditional regression modeling with data from all 6 examination periods (n = 23,633 observations) was used to examine associations between walking and annualized 15-y weight change, with control for 15-y nonwalking physical activity, baseline weight (and their interaction), marital status, education, smoking, calorie intake, and baseline age, race, and field center.
  
  
  RESULTS
  Mean (+/- SE) baseline weights were 77.0 +/- 0.3 kg (men) and 66.2 +/- 0.3 kg (women), weight gain was approximately 1 kg/y, and the mean duration of walking at baseline was <15 min/d. After accounting for nonwalking physical activity, calorie intake, and other covariates, we found a substantial association between walking and annualized weight change; the greatest association was for those with a larger baseline weight. For example, for women at the 75th percentile of baseline weight, 0.5 h of walking/d was associated with 8 kg less weight gain over 15 y compared with women with no leisure time walking.
  
  
  CONCLUSIONS
  Walking throughout adulthood may attenuate the long-term weight gain that occurs in most adults.
authors.affiliation: Department of Nutrition, School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27516-3997, USA. gordon_larsen@unc.edu
authors.forename: Penny
authors.initials: P
authors.lastname: Gordon-Larsen
authors.forename: Ningqi
authors.initials: N
authors.lastname: Hou
authors.forename: Steve
authors.initials: S
authors.lastname: Sidney
authors.forename: Barbara
authors.initials: B
authors.lastname: Sternfeld
authors.forename: Cora E
authors.initials: CE
authors.lastname: Lewis
authors.forename: David R
authors.initials: DR
authors.lastname: Jacobs
authors.forename: Barry M
authors.initials: BM
authors.lastname: Popkin
mesh_terms: D000293:Adolescent; D000328:Adult; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology*; D004522:Educational Status; D002149:Energy Intake / Q000502:physiology*; D005260:Female; D006801:Humans; D007899:Leisure Activities; D008137:Longitudinal Studies; D008297:Male; D017533:Marital Status; D009765:Obesity / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D011446:Prospective Studies; D012907:Smoking; D011795:Surveys and Questionnaires; D016138:Walking / Q000502:physiology*; D015430:Weight Gain / Q000502:physiology; D055815:Young Adult