The Influence of Friends and Psychosocial Factors on Physical Activity and Screen Time in Normal and Overweight Adolescents: A Mixed-Methods Analysis.

BACKGROUND: Understanding factors that influence physical activity (PA) and sedentary behavior is crucial to develop interventions to improve adolescents' health-related behaviors.

PURPOSE: To compare the influence of friends and psychosocial factors on moderate-to-vigorous physical activity (MVPA) and screen time (ST) between normal weight (NW) and overweight (OW) adolescents.

METHODS: In all, 21 OW and 21 NW adolescents wore accelerometers and completed questionnaires assessing MVPA, ST, and psychosocial variables. The MVPA and ST were assessed in nominated friends. Adolescents participated in focus groups assessing influence on activity behaviors.

RESULTS: There were no differences in MVPA; however, NW adolescents reported less ST than OW adolescents (8.9 vs 13.1 h/wk, P = .04). For OW adolescents, friends' ST ( P = .002) and psychosocial factors ( P = .05) were associated with ST, while only PA self-efficacy was associated with MVPA. For NW adolescents, only friends' MVPA ( P = .04) was associated with self-reported PA. Exploratory analyses revealed differences among weight status and gender. Focus group discussions revealed that friends influenced both OW and NW adolescents' MVPA; however, this appeared to be more apparent for NW males, while psychosocial factors played a role in both OW and NW females. The OW adolescents reported that friends were more of an influence on their ST levels, while NW adolescents indicated that their ST was not affected by their friends' behaviors.

CONCLUSIONS: Interventions to increase MVPA and/or decrease ST may need to be tailored for NW and OW adolescents.