title: Accelerometer-measured physical activity is not associated with two-year weight change in African-origin adults from five diverse populations.
abstract: BACKGROUND
  Increasing population-levels of physical activity (PA) is a controversial strategy for managing the obesity epidemic, given the conflicting evidence for weight loss from PA aloneper se. We measured PA and weight change in a three-year prospective cohort study in young adults from five countries (Ghana, South Africa, Jamaica, Seychelles and USA).
  
  
  METHODS
  A total of 1,944 men and women had baseline data, and at least 1 follow-up examination including measures of anthropometry (weight/BMI), and objective PA (accelerometer, 7-day) following the three-year study period. PA was explored as 1-minute bouts of moderate and vigorous PA (MVPA) as well as daily sedentary time.
  
  
  RESULTS
  At baseline; Ghanaian and South African men had the lowest body weights (63.4 ± 9.5, 64.9 ± 11.8 kg, respectively) and men and women from the USA the highest (93.6 ± 25.9, 91.7 ± 23.4 kg, respectively). Prevalence of normal weight ranged from 85% in Ghanaian men to 29% in USA men and 52% in Ghanaian women to 15% in USA women. Over the two-year follow-up period, USA men and Jamaican women experienced the smallest yearly weight change rate (0.1 ± 3.3 kg/yr; -0.03 ± 3.0 kg/yr, respectively), compared to South African men and Ghanaian women greatest yearly change (0.6.0 ± 3.0 kg/yr; 1.22 ± 2.6 kg/yr, respectively). Mean yearly weight gain tended to be larger among normal weight participants at baseline than overweight/obese at baseline. Neither baseline MVPA nor sedentary time were associated with weight gain. Using multiple linear regression, only baseline weight, age and gender were significantly associated with weight gain.
  
  
  CONCLUSIONS
  From our study it is not evident that higher volumes of PA alone are protective against future weight gain, and by deduction our data suggest that other environmental factors such as the food environment may have a more critical role.
authors.affiliation: Public Health Sciences, Stritch School of Medicine, Loyola University Chicago , Maywood , IL , United States.
authors.forename: Lara R
authors.initials: LR
authors.lastname: Dugas
authors.affiliation: Department of Orthopedics & Rehabilitation, University of Wisconsin, Madison , Madison , WI , United States.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Kliethermes
authors.affiliation: Department of Physiology, Kwame Nkrumah University of Science and Technology , Kumasi , Ghana.
authors.forename: Jacob
authors.initials: J
authors.lastname: Plange-Rhule
authors.affiliation: Public Health Sciences, Stritch School of Medicine, Loyola University Chicago , Maywood , IL , United States.
authors.forename: Liping
authors.initials: L
authors.lastname: Tong
authors.affiliation: Institute of Social & Preventive Medicine, Lausanne University Hospital, Lausanne, VD, Switzerland; Ministry of Health, Victoria, Republic of Seychelles.
authors.forename: Pascal
authors.initials: P
authors.lastname: Bovet
authors.affiliation: Solutions for Developing Countries, University of West Indies, Mona , Kingston , Jamaica.
authors.forename: Terrence E
authors.initials: TE
authors.lastname: Forrester
authors.affiliation: Division of Exercise Science and Sports Medicine, Health Sciences, University of Cape Town , Cape Town , South Africa.
authors.forename: Estelle V
authors.initials: EV
authors.lastname: Lambert
authors.affiliation: Nutritional Sciences, University of Wisconsin, Madison , Madison , WI , United States.
authors.forename: Dale A
authors.initials: DA
authors.lastname: Schoeller
authors.affiliation: Public Health Sciences, Stritch School of Medicine, Loyola University Chicago , Maywood , IL , United States.
authors.forename: Ramon A
authors.initials: RA
authors.lastname: Durazo-Arvizu
authors.affiliation: Public Health Sciences, Stritch School of Medicine, Loyola University Chicago , Maywood , IL , United States.
authors.forename: David A
authors.initials: DA
authors.lastname: Shoham
authors.affiliation: Public Health Sciences, Stritch School of Medicine, Loyola University Chicago , Maywood , IL , United States.
authors.forename: Guichan
authors.initials: G
authors.lastname: Cao
authors.affiliation: MRC Epidemiology Unit, University of Cambridge , Cambridge , United Kingdom.
authors.forename: Soren
authors.initials: S
authors.lastname: Brage
authors.affiliation: MRC Epidemiology Unit, University of Cambridge, Cambridge, United Kingdom; Department of Sport Medicine, Norwegion School of Sport Sciences, Oslo, Norway.
authors.forename: Ulf
authors.initials: U
authors.lastname: Ekelund
authors.affiliation: Public Health Sciences, Stritch School of Medicine, Loyola University Chicago , Maywood , IL , United States.
authors.forename: Richard S
authors.initials: RS
authors.lastname: Cooper
authors.affiliation: Public Health Sciences, Stritch School of Medicine, Loyola University Chicago , Maywood , IL , United States.
authors.forename: Amy
authors.initials: A
authors.lastname: Luke
keywords: Obesity; Physical activity; Weight gain