Predictors of overweight/obesity in a Brazilian cohort after 13 years of follow-up

Background: Obesity is a chronic complex disease with an increasing prevalence around the world. Prospective studies in adult cohorts are needed to provide information about predictors of new-onset overweight/obesity on population-based levels. The aim of this study was to identify factors associated with the risk of an adult individual become overweight/obese after 13 years of follow-up. Methods: Second phase of an observational population-based prospective cohort study in a small town in the Midwest region of Brazil. A representative sample of the adult population (>= 18 years) was assessed, in 2002 (phase 1). Anthropometric, sociodemographic, dietary intake and lifestyle data were collected. After 13 years of follow-up (2015), the same variables were re-evaluated (phase 2). New-onset overweight/obesity was the outcome variable. Results: A total of 685 subjects were included, with a mean age in phase 1 of 42.7 +/- 13.8 years and. 56.1 +/- 13. 8 years in phase 2, the mean follow-up time was 13.2 years and female sex counted for 66.3% of the sample. Total weight gain was 5.9 +/- 10.2 Kg, body mass index increased 2.6 +/- 3.8 Kg/m(2) and waist circumference (WC) values increased 8.0 +/- 10.5 cm. The prevalence of overweight/obesity went from 49.1% in phase 1 to 69.8% in phase 2 (p<0.001). The factors associated with a decreased, risk of new-onset overweight/obesity were ages between 50 and 64 (RR 0.40; CI 0.24-0.67 - p = 0.001) and >= 65 years (RR 0.15; CI 0.06-0.35 - p<0.001), being part of the second quartile of fat consumption (RR 0.59; CI 0.35-0.97 - p = 0.041), no alcohol consumption (RR 0.59; CI 0.37-0.93 - p = 0.024) and smoking (RR 0.58; CI 0.39-0.86 - p = 0,007) in phase 1. Conclusions: We identified in thirteen years of follow-up that older ages, a moderate fat consumption compared to low consumption, no alcohol consumption and smoking habit were related to a decreased risk of new-onset overweight/obesity. Obesity prevention actions must focus on subjects at younger ages and include policies to reduce alcohol consumption.