title: Protocol for the modeling the epidemiologic transition study: a longitudinal observational study of energy balance and change in body weight, diabetes and cardiovascular disease risk.
abstract: BACKGROUND
  The prevalence of obesity has increased in societies of all socio-cultural backgrounds. To date, guidelines set forward to prevent obesity have universally emphasized optimal levels of physical activity. However there are few empirical data to support the assertion that low levels of energy expenditure in activity is a causal factor in the current obesity epidemic are very limited.
  
  
  METHODS
  The Modeling the Epidemiologic Transition Study (METS) is a cohort study designed to assess the association between physical activity levels and relative weight, weight gain and diabetes and cardiovascular disease risk in five population-based samples at different stages of economic development. Twenty-five hundred young adults, ages 25-45, were enrolled in the study; 500 from sites in Ghana, South Africa, Seychelles, Jamaica and the United States. At baseline, physical activity levels were assessed using accelerometry and a questionnaire in all participants and by doubly labeled water in a subsample of 75 per site. We assessed dietary intake using two separate 24-hour recalls, body composition using bioelectrical impedance analysis, and health history, social and economic indicators by questionnaire. Blood pressure was measured and blood samples collected for measurement of lipids, glucose, insulin and adipokines. Full examination including physical activity using accelerometry, anthropometric data and fasting glucose will take place at 12 and 24 months. The distribution of the main variables and the associations between physical activity, independent of energy intake, glucose metabolism and anthropometric measures will be assessed using cross-section and longitudinal analysis within and between sites.
  
  
  CONCLUSIONS
  METS will provide insight on the relative contribution of physical activity and diet to excess weight, age-related weight gain and incident glucose impairment in five populations' samples of young adults at different stages of economic development. These data should be useful for the development of empirically-based public health policy aimed at the prevention of obesity and associated chronic diseases.
authors.affiliation: Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA. aluke@lumc.edu
authors.forename: Amy
authors.initials: A
authors.lastname: Luke
authors.forename: Pascal
authors.initials: P
authors.lastname: Bovet
authors.forename: Terrence E
authors.initials: TE
authors.lastname: Forrester
authors.forename: Estelle V
authors.initials: EV
authors.lastname: Lambert
authors.forename: Jacob
authors.initials: J
authors.lastname: Plange-Rhule
authors.forename: Dale A
authors.initials: DA
authors.lastname: Schoeller
authors.forename: Lara R
authors.initials: LR
authors.lastname: Dugas
authors.forename: Ramon A
authors.initials: RA
authors.lastname: Durazo-Arvizu
authors.forename: David
authors.initials: D
authors.lastname: Shoham
authors.forename: Richard S
authors.initials: RS
authors.lastname: Cooper
authors.forename: Soren
authors.initials: S
authors.lastname: Brage
authors.forename: Ulf
authors.initials: U
authors.lastname: Ekelund
authors.forename: Nelia P
authors.initials: NP
authors.lastname: Steyn
mesh_terms: D000328:Adult; D001835:Body Weight; D002318:Cardiovascular Diseases / Q000453:epidemiology*; D015331:Cohort Studies; D003920:Diabetes Mellitus / Q000209:etiology*; D004734:Energy Metabolism / Q000502:physiology*; D016021:Epidemiologic Studies; D005260:Female; D006801:Humans; D038622:Internationality; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D009043:Motor Activity / Q000502:physiology*; D009765:Obesity; D018570:Risk Assessment; D011795:Surveys and Questionnaires