title: Active transport, physical activity, and body weight in adults: a systematic review.
abstract: BACKGROUND
  Physical activity has various health benefits. Active transport can contribute to total physical activity and thus affect body weight because of increased energy expenditure. This review summarizes published evidence on associations of active transport, general physical activity, and body weight in adults.
  
  
  METHODS
  A systematic review of the literature was conducted in October 2010 using eight databases. A total of 14,216 references were screened; full texts were retrieved for 95 articles. Forty-six articles (36 unique studies) were included: 20 (17) from Europe; 18 (13) from North America, Australia, and New Zealand; and eight (six) from other countries. Analyses of the retrieved papers were carried out between November 2010 and March 2011.
  
  
  RESULTS
  Of 15 studies assessing active transport and physical activity, five found associations in the expected direction (more active transport associated with more physical activity) for all or most variables studied, nine found some associations, and one reported no associations. Of 30 studies assessing active transport and body weight, 13 reported associations in the expected direction (more active transport associated with lower body weight) for all or most variables studied, 12 found some associations, two presented some associations in the expected and some in the opposite direction, and three reported no associations.
  
  
  CONCLUSIONS
  There is limited evidence that active transport is associated with more physical activity as well as lower body weight in adults. However, study heterogeneity, predominantly cross-sectional designs, and crude measures for active transport and physical activity impede quantitative conclusions.
authors.affiliation: Physical Activity and Health Unit, Institute of Social and Preventive Medicine, University of Zurich, Switzerland. miriam.wanner@uzh.ch
authors.forename: Miriam
authors.initials: M
authors.lastname: Wanner
authors.forename: Thomas
authors.initials: T
authors.lastname: Götschi
authors.forename: Eva
authors.initials: E
authors.lastname: Martin-Diener
authors.forename: Sonja
authors.initials: S
authors.lastname: Kahlmeier
authors.forename: Brian W
authors.initials: BW
authors.lastname: Martin
mesh_terms: D001642:Bicycling / Q000706:statistics & numerical data; D015992:Body Mass Index; D001835:Body Weight; D015444:Exercise; D014943:Global Health; D006801:Humans; D008124:Locomotion; D014186:Transportation / Q000379:methods*; D016138:Walking / Q000706:statistics & numerical data