Diet and exercise of adolescents and their peers

All over the world, adolescent obesity is a serious health problem. Many researchers have focused on diet and exercise, because those behaviors are modifiable risk factors for obesity. To reduce or prevent the prevalence of adolescent obesity, contributions of diverse contextual factors to adolescents’ diet and exercise have been studied. However, little is known about peer influences on adolescents’ diet and exercise, compared to the studies of other contextual factors such as parents and school.

In addition, in contrast to Western countries with higher prevalence of adolescent obesity, few studies have been conducted in countries with different cultures. Exploring the influence of peers on diet and exercise of adolescents in those countries could help to develop culturally-appropriate interventions to prevent adolescents from becoming obese. Thus, the purpose of this set of three studies was to examine adolescents’ diet and exercise in the context of peer factors and relationships.

The purpose of the first study was to systematically review research assessing contribution of peer to adolescents’ diet and exercise. Twenty four articles were identified, using the electronic databases, PubMed, CINAHL, Web of Science, and SCOPUS. According to the findings from this review, the diet and exercise of adolescents was positively associated with that of their peers. Additionally, gender, the type of diet and exercise, and the closeness of friends could influence these associations.

The second study identified the parent-, school-, and peer-factors contributing to dietary and exercise behaviors of adolescents in the United States, by using data from the Health Behaviour of School-Aged Children study. Findings from the current analysis indicated that parent- and peer-factors could influence either diet or exercise of adolescents; while school-factor were found to be associated only with adolescents’ diet.

The third study explored the diet and exercise of Korean female adolescents within their classroom-based peer networks. Using social network analysis, dietary behaviors of female adolescents in this study were clustered within their classrooms. Several adolescents played a role in bridging two or more peer networks. However, less information about female adolescents’ exercise behaviors within classroom-based peer network was obtained.

In summary, peers are an important contextual factor for developing adolescents’ diet and exercise behaviors that could contribute to adolescent obesity. These associations could be influenced by the characteristics of friendships such as gender of friends, the closeness of friends, and network characteristics of friendships. Peers can be potential targets for interventions to reduce or prevent the development of adolescent obesity.