Final answer:
Among the provided options, 'peer influence' is a significant contextual factor affecting adolescent engagement in regular exercise, in addition to the influence of the family and use of TV/computers. These factors collectively shape health behaviors and the importance of addressing them can help reduce the risk of obesity.
Step-by-step explanation:
The question asks about three contextual factors that influence whether or not adolescents engage in regular exercise. Among the options given, peer influence is a significant factor that affects adolescents' exercise habits, in addition to the influence of family and use of TV/computers.
Family influence includes the behaviors and attitudes that parents and siblings display towards physical activity, which can encourage or discourage an adolescent from exercising. High usage of TV/computers can lead to a sedentary lifestyle, reducing the time available for physical activity. Peer influence plays a crucial role in an adolescent's life, and friends can impact their decisions to engage in regular exercise positively or negatively.
It is essential to address not just dietary concerns but also to promote physical activity and understanding the environmental and social factors that can affect an adolescent's health behaviors. Moreover, emphasizing the importance of healthy eating and exercise as a fundamental part of a child's education can lead to long-term benefits in reducing the risk of obesity and other health issues.