Accumulated exposure to rural areas of residence over the life course is associated with overweight and obesity in adulthood: a 25-year prospective cohort study.
Patterson KAE., Gall SL., Venn AJ., Otahal P., Blizzard L., Dwyer T., Cleland VJ.
This prospective cohort study investigated whether body mass index (BMI) and weight status in mid-adulthood were predicted by trajectories of urban-rural residence from childhood to adulthood.Participants aged 7-15 years in 1985 (n = 8498) were followed up in 2004-2006 (n = 3999, aged 26-36 years) and 2009-2011 (n = 3049, aged 31-41 years). Area of residence (AOR) was classified as urban or rural at each time point. BMI and/or weight status was calculated from self-reported weight and height (2009-2011). We tested which of three life-course models ("accumulation," "sensitive period," "mobility") best explained the AOR-BMI and/or weight status association using a novel life-course modeling framework.Accumulation and sensitive period models best described the effect of AOR on mid-adulthood BMI and weight status. Those with greater accumulated exposure to rural areas had a higher BMI (β = 0.29 kg/m2 per time in a rural area, P = .005) and were more likely obese (relative risk = 1.13 per time in a rural area, P = .002). Living in rural areas at ages 26-30 years was also associated with a higher BMI and obesity in mid-adulthood.Greater cumulative exposure to rurality and exposure during the "sensitive period" of young adulthood is associated with obesity in middle-aged adults. This study highlights the important contribution of context to the development of obesity over the life course.