Introduction: During adolescence, a period marked by rapid identify formation and peer comparison, low weight satisfaction may undermine self-esteem and amplify perceived peer pressure. These effects may prompt students to engage in compensatory academical behaviors to gain approval or avoid rejection by others, thereby elevating their academic stress, which in turn may influence academic achievement. This study aims to investigate the associations among weight satisfaction, academic stress, and academic achievement among adolescents, and to explore gender (boys vs. girls) and school stage (primary vs. secondary) differences in these links.


Method: Participants were 26,146 Chinese adolescents (Mage = 12.46, 47.2% female). We conducted multi-group structural equation modeling to examine the associations and group differences.


Results: Lower weight satisfaction was associated with higher academic stress, which in turn predicted lower academic achievement. Gender moderated these associations differently across school stages. In primary school, the negative link between weight satisfaction and academic achievement was stronger among girls compared to boys. In middle school, the negative association between weight satisfaction and academic stress was stronger among girls than boys. Subsequently, the negative association between academic stress and academic achievement (b path) was also more evident in girls compared to boys.


Discussion: Findings highlight gender- and stage-specific patterns linking weight satisfaction, academic stress, and achievement. Girls with lower weight satisfaction, particularly in middle school, may experience heightened academic pressures and stress, leading to poorer performance. Moreover, the stronger indirect effect of weight satisfaction on academic achievement via academic stress among girls further underscores the importance of early, targeted interventions to foster positive body image—especially among girls transitioning into secondary education—to interrupt the cascade from weight dissatisfaction to elevated stress and poorer academic outcomes.