Your Classmates Eat Junk Food and You Become Depressed—the Peer Effects of Junk Food Consumption on Depression

Abstract

A growing body of literature has demonstrated the impacts of peers’ dietary patterns on one’s dietary behaviors as well as the positive relationship between junk food consumption and depressive symptoms. However, researchers have not linked these two associations and paid scant attention to the mechanisms in the associations. This study examines how peers’ junk food consumption is related to one’s depressive symptoms among junior high students in China and explores the underlying mechanisms. We relied on path models to explore data from the Chinese Education Panel Survey (CEPS). The analytic sample consisted of 8221 Chinese junior high students. The path analysis decomposed the total effect of peers’ junk food consumption on one’s level of depression into direct and indirect effects. Results revealed that peers’ junk food consumption is consequential to one’s level of depression among Chinese junior high students. There were three underlying pathways: (1) peers’ junk food consumption → self’s junk food consumption → self’s depression, (2) peers’ junk food consumption → self’s junk food consumption → self-rated body shape → self’s depression, and (3) peers’ junk food consumption → self’s junk food consumption → self’s sleep quality → self’s depression. The findings supported the social learning theory, which argues that people are most likely to model the behaviors of individuals with whom they socialize more often, i.e., the peers in this research.