Background: Recent lifestyle changes have increased the prevalence of dyslipidemia in Korea. Young men are known to have a low awareness of dyslipidemia and a lack of motivation to maintain their weight. However, the association between weight change and dyslipidemia in young adults has not been thoroughly examined. Methods: Data from the Armed Forces Medical Command Defense Medical Information System database were used. In this study, 15,068 soldiers who underwent private and corporal health examinations between May 2020 and April 2022 were included. The difference in weights between the two different health examinations was used to quantify weight change. Four components of the lipid profile were used to assess dyslipidemia during the corporal health examination. Results: After adjusting for relevant covariates, weight gain was associated with increased risk of dyslipidemia (adjusted odds ratio [OR], 1.38 [95% confidence interval, CI, 1.15 to 1.64] for the 5% to 10% weight gain group; and OR, 2.02 [95% CI, 1.59 to 2.55] for the ≥10% weight gain group), whereas weight loss was associated with decreased risk (adjusted OR, 0.82 [95% CI, 0.68 to 0.98] for the 5% to 10% weight loss group; and OR, 0.38 [95% CI, 0.27 to 0.53] for the ≥10% weight loss group). In subgroup analysis bas...