Neighborhoods and obesity in older adults: the Baltimore Memory Study

Obesity has reached epidemic proportions. Although its causes are not well understood, its increasing prevalence is not likely to be due to genetic factors or underlying biology. This has led to interest in the role of environmental factors, although few studies have focused on the role of the social environment. This study investigated whether neighborhood psychosocial hazards independent of individual risk factors were associated with increased odds of obesity.

Baseline data were analyzed in 2005 from a cohort study of 1140 randomly selected community-dwelling men and women aged 50 to 70 years from 65 contiguous neighborhoods in Baltimore MD. Body mass index (BMI in kilograms/meters squared) was calculated from measured height and weight at baseline (2001-2002). People with a BMI of 30 and higher were considered obese. Multilevel logistic regression was used to examine associations between a 12-item scale of neighborhood psychosocial hazards and the odds of obesity.

Thirty-eight percent of the cohort were obese. Residents of neighborhoods in the highest quartile of the Neighborhood Psychosocial Hazards scale were nearly twice as likely to be obese compared to residents in the least-hazardous neighborhoods (53% vs 27%). After adjustment for age, gender, race/ethnicity, education, household wealth, alcohol consumption, tobacco use, self-reported physical activity, and dietary intake, living in more hazardous neighborhoods was associated with a graded increase in the odds of obesity. This association was partially mediated by physical activity.

Even after controlling for a large set of demographic, behavioral, and socioeconomic individual-level risk factors, living in a neighborhood with greater psychosocial hazards was independently associated with obesity.