Socioeconomic status, race, and body mass index: the mediating role of physical activity and sedentary behaviors during adolescence.
OBJECTIVE
To assess how sociodemographic and activity behaviors contribute to adolescent body mass index (BMI).


METHODS
One hundred and thirteen adolescents (M = 17 years; 42% Caucasian, 56% African American) were assessed on BMI. Teens reported activity levels and caregivers reported socioeconomic status (SES).


RESULTS
Adolescents from lower SES backgrounds, and from minority groups, had higher BMI (r = -.26, p < .01 and t(110) = -3.01, p < .01). Formal statistical mediation tests revealed that sedentary behaviors significantly mediated the association between SES and BMI (Z = 2.31, p < .05), whereas physical activity significantly mediated the race-BMI association (Z = 2.32, p < .05).


CONCLUSIONS
Interventions targeting teen BMI could benefit by aiming to decrease sedentary behavior in low SES teens and increase physical activity in teens from minority groups.
Hanson
Margaret D
MD
Department of Psychology, University of British Columbia, Vancouver, BC, Canada. hansonm@psych.ubc.ca
Chen
Edith
E
D000293:Adolescent; D000328:Adult; D015992:Body Mass Index; D005006:Ethnicity; D005260:Female; D006801:Humans; D008297:Male; D009043:Motor Activity; D009765:Obesity / Q000453:epidemiology*; D011187:Posture; D012959:Socioeconomic Factors