Physical Activity and Body-Mass-Index: Do Family, Friends and Teachers Restrain the Risk for Physical Inactivity in Adolescents?

Background: The present study investigates the role of different sources of social support in the relationship of BMI and PA in an international sample of children and adolescents. Methods: Data included 170,211 adolescents (51.5% female), aged 10-16 (M = 13.6, SD = 1.64) from 37 European countries/regions and were retrieved from the 2013/14 Health Behaviour in School-aged Children (HBSC) international database. Results: PA levels in adolescents are lower for girls, decrease with age, and are lower for overweight and obese adolescents compared to underweight and normal-weight adolescents. Peer support and teacher support significantly predict PA (ORpeer = 1.11; ORteacher = 0.97) and vigorous PA frequency (ORpeer = 1.13; ORteacher = 0.94). Family support only affected vigorous PA frequency (OR = 1.03). Family support had a moderating effect on PA in overweight (ORfamily*BMI(overweight) = 0.94) and obese (ORfamily*BMI(obese) = 0.90) adolescents. Peer support had a moderating effect on vigorous PA frequency in obese (ORpeer*BMI(obese) = 1.08) adolescents. Teacher support had a moderating effect on PA (ORteacher*BMI(normal) = 1.05; ORteacher*BMI(overweight) = 1.09) and vigorous PA frequency (ORteacher*BMI(normal) = 1.07; ORteacher*BMI(overweight) = 1.08) in normal-weight and overweight adolescents. Conclusion: Social support helps adolescents to be active. Especially for obese adolescents, support by and relations with peers are important to reach a significant amount of PA.

Automated summary

The study found that peer support and teacher support play an important role in the physical activity levels of adolescents, especially for obese adolescents. Family support only impacts vigorous physical activity frequency, while peer support and teacher support have moderating effects on physical activity in adolescents of different weight status.