Background <p>Adolescence is a developmental stage during which appearance becomes a significant concern, and approximately one-third of adolescents engage in weight loss behaviors. Unhealthy weight loss behaviors in adolescents are often associated with both physical and psychological health and persist into adulthood. This study aimed to categorize weight loss behaviors in adolescents using a latent class analysis and examine the covariates and differences in body mass index across groups.</p> Methods <p>Data were obtained from 16,074 adolescents who reported recent weight loss efforts in the 18th Korea Youth Risk Behavior Web-based Survey. The following nine weight loss behaviors (past 30 days) were assessed: performing regular exercise; fasting (≥ 24&#xa0;h); eating less; eating diet foods; using diet pills with a prescription from a physician; using diet pills without a prescription from a physician; vomiting or using laxatives/diuretics; eating a one-food diet; and using herbal medicine prescribed by a traditional medicine physician.</p> Results <p>In this study, 83.7% of respondents were classified as class 1, including those who performed regular exercise and engaged in eating less. Respondents in class 2 (1.2%) engaged in unhealthy behaviors such as fasting (≥ 24&#xa0;h), eating diet foods, and using unprescribed medication. Respondents in class 3 (15.1%) engaged in healthy behaviors, following a one-food diet and eating diet food. Respondents in class 2 and 3 were significantly associated with anxiety, depression, suicidal ideation, smoking, and alcohol consumption.</p> Conclusions <p>This study highlighted the diverse weight loss behaviors, psychological factors, and risk behaviors among adolescents, indicating the need for tailored interventions to replace unhealthy weight loss behaviors and incorporate psychological support. Our findings contribute to a better understanding of adolescent weight loss behaviors and may aid in the development of tailored interventions.</p>