Influence of individual- and area-level measures of socioeconomic status on obesity, unhealthy eating, and physical inactivity in Canadian adolescents.

BACKGROUND Low socioeconomic status (SES) is a risk factor for obesity. However, few studies have used a multilevel analysis to determine the influence of both individual- and area-level determinants of SES on obesity, and these studies have been limited to adults. OBJECTIVE The primary objective was to examine associations between individual- and area-level measures of SES and obesity among adolescents by using a multilevel analytic approach. A secondary objective was to examine associations between individual- and area-level measures of SES with unhealthy eating and physical inactivity. DESIGN The study sample consisted of 6684 youth in grades 6-10 from 169 schools across Canada. Individual-level SES exposures included material wealth and perceived family wealth. Area-level SES exposures included unemployment rate, percentage of adult residents with less than a high school education, and average employment income from head of household. Associations between SES and the outcome measures were examined by using multilevel logistic regression procedures that modeled students (individual level) nested within schools (area level). RESULTS Both individual-level and all 3 area-level SES measures were inversely associated with obesity. The odds for unhealthy eating were increased for those living in an area with a low percentage of residents with a high school education. The odds of being physically inactive increased with decreasing levels of material wealth and perception of family wealth. CONCLUSIONS Individual- and area-level SES measures were independently related to obesity, which suggests that both individual and environmental approaches may be required to curtail adolescent obesity.