A longitudinal cohort study examining determinants of overweight and obesity in adulthood.

OBJECTIVES: Adulthood overweight and obesity are multifaceted conditions influenced by a combination of biological, environmental and socio-cultural factors across the lifespan. Using a longitudinal study design, we aimed to identify determinants of adulthood overweight and obesity, in relation to: 1) childhood and life course factors, 2) geographical differences in air quality, and 3) gender-specific factors, in a cohort followed from childhood into adulthood.

METHODS: Childhood data were acquired (1978-1986) from children residing in four distinct Hamilton neighbourhoods (Ontario, Canada), including air-quality assessments. Adulthood data were obtained (2006-2007) from successfully retraced participants (n = 315) using comprehensive self-administered questionnaires. Multivariate logistic regressions were used to evaluate determinants of adulthood overweight (BMI: 25-29.9 kg/m2) and obesity (BMI: ≥30).

RESULTS: The prevalence of normal weight decreased drastically at follow-up in adulthood, while that of overweight and obesity increased. Both overweight and obesity in adulthood were associated with male gender and occupational exposures to contaminants. Childhood residence in Hamilton neighbourhoods with better air quality was associated with lesser odds of adulthood overweight, whereas adulthood obesity was strongly linked to childhood weight gain (overweight or obesity). Among females, childhood weight status predicted overweight and obesity in adulthood, with always living in Hamilton, lack of additional health insurance, negative self-appraisal and high blood pressure during adulthood identified as other significant predictors. Among males, prolonged occupational exposures to contaminants emerged as a unique determinant of adulthood weight gain.

CONCLUSION: Adulthood overweight and obesity are associated with childhood and life course determinants, including childhood weight status, residential air quality and occupational contaminant exposures, in a gender-specific manner.