Incidence of excess body weight and annual weight gain in women and men: Results from the ELSA-Brasil cohort.

OBJECTIVE To estimate annual weight gain and the incidence of overweight and obesity, stratified according to gender and socioeconomic factors. METHODS From the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), we included 13 625 women and men aged 35-74 (2008-2010) who attended a follow-up visit after a mean 3.8-years. Standardized questionnaires were used to record sociodemographic data, and height and weight were measured on all participants during in-person visits at research centers. The incidence rate to overweight was calculated among those not having excess weight at baseline, and incident obesity among those not having this condition at baseline. We evaluated the incidence of overweight and obesity in men and women, adjusted by age, through Poisson regression with robust variance. Large annual weight gain by gender was being defined as ≥90th percentile in the cohort. RESULTS A global incidence of 7.7% for overweight and 10.6% for obesity was observed, with higher levels seen among black woman (28.5%), young men (21.1%) and woman with low educational level (35.0%). The proportions of overweight and obesity increased with age at both time points, more commonly among those with the lowest levels of per capita income and fewer years of schooling. Large annual weight gain was greater among participants with an intermediate level of education and those who self-identified as black. CONCLUSIONS A high overall risk of becoming overweight/obese was found, especially among women. The roles of race and education level are fundamental to understanding the effects produced by social inequalities in rates of excess weight.