Environmental factors associated with overweight among adults in Nigeria

Understanding environmental factors related to obesity can inform interventions for the world wide obesity epidemic, yet no study has been conducted in this context in Africa. This study examined associations between neighbourhood environment variables and overweight in Nigerian adults. A total of 1818 randomly selected residents (age: 20-65 years, 40% female, 31% overweight and 61.2% response) living in high and low socioeconomic (SES) neighbourhoods in Metropolitan Maiduguri, Nigeria, participated in a cross-sectional study. Anthropometric measurements of height and weight and an interview-assisted self-reported measure of 16 items of perceived neighborhood environments were conducted. The primary outcome was overweight (body mass index [BMI] > or = 25 kg/m(2)) vs. normal weight (BMI = 18.5-24.9 kg/m(2)). After adjustment for sociodemographic variables, overweight was associated with distant access to commercial facilities (odds ratio [OR], 1.49; 95% confidence interval [CI], 1.02- 2.18), poor neighbourhood aesthetics (OR, 1.58; 95% CI, 1.16-2.09), perceiving garbage and offensive odours in the neighbourhood (OR, 1.41; 95% CI, 1.05-1.89) and feeling unsafe from crime at night (OR, 1.47; 95% CI, 1.13- 1.91) and unsafe from traffic (OR, 1.56; 95% CI, 1.17-2.07) in the total sample. Significant interactions regarding overweight were found between gender and four environmental variables, with low residential density (OR, 1.39; 95% CI, 1.02-1.93) and poorly maintained pedestrian pathways (OR, 1.89; 95% CI, 1.13-3.17) associated with overweight in men only, and absence of beautiful things (OR, 2.23; 95% CI, 1.42-3.50) and high traffic making it unsafe to walk (OR, 2.39; 95% CI, 1.49-3.83) associated with overweight in women only. There were few significant interactions between environmental factors and neighborhood SES regarding overweight. Neighbourhood environment factors were associated with being overweight among Nigerian adults. These findings support previous reports in international literature, but should be replicated in other African studies before any firm conclusions can be drawn.