title: Maintaining a Healthy BMI: Data From a 16-Year Study of Young Australian Women.
abstract: The aims of this prospective cohort study were to examine 16-year trajectories of weight and BMI in young adult women who had a healthy BMI in 1996 and determinants of remaining in the healthy BMI category.
  
  
  
  A total of 4,881 women with healthy BMI at baseline and either healthy, overweight, or obese BMI at 16-year follow-up reported their weight, height, health, and health behaviors in six surveys of the Australian Longitudinal Study on Women's Health between 1996 (aged 18-23 years) and 2012 (aged 34-39 years). Determinants of BMI maintenance were estimated using binary logistic regression and generalized estimating equations in 2015.
  
  
  
  Almost 60% remained in the healthy BMI category from 1996 to 2012, (mean weight gain, 0.19 kg/year), 29% transitioned to overweight BMI (0.83 kg/year), and 11.6% transitioned to obese (1.73 kg/year). The mean rates of annual weight gain in each group were consistent over time. Only three factors (low alcohol, moderate/high physical activity, having a university degree) were positively associated with maintaining a healthy BMI. Additional behavioral factors (smoking, high sitting time, energy intake, dieting, takeaway food, and use of oral contraceptives), as well as blue collar occupation, separation/divorce/widowhood, and major illness were negatively associated with BMI maintenance.
  
  
  
  To prevent the transition from healthy to overweight/obese BMI, weight gain must be limited to <0.5 kg/year. Women with healthy BMI, but with higher rates of weight gain in their early 20s, could be identified by health professionals for assistance with prevention of becoming overweight/obese.
authors.affiliation: Centre for Research on Exercise, Physical Activity and Health, School of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane, Queensland, Australia. Electronic address: wbrown@uq.edu.au.
authors.forename: Wendy J
authors.initials: WJ
authors.lastname: Brown
authors.affiliation: School of Agricultural, Computational and Environmental Sciences, University of Southern Queensland, Toowoomba, Queensland, Australia.
authors.forename: Enamul
authors.initials: E
authors.lastname: Kabir
authors.affiliation: Centre for Research on Exercise, Physical Activity and Health, School of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane, Queensland, Australia; Cancer Prevention Research Centre, School of Public Health, The University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Bronwyn K
authors.initials: BK
authors.lastname: Clark
authors.affiliation: Centre for Research on Exercise, Physical Activity and Health, School of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Sjaan R
authors.initials: SR
authors.lastname: Gomersall
mesh_terms: D000293:Adolescent; D000328:Adult; D001315:Australia / Q000453:epidemiology; D015992:Body Mass Index; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008019:Life Style; D009765:Obesity / Q000453:epidemiology*; D055815:Young Adult