Abstract: Objective: To explore the correlation of the dietary inflammatory index (DII) and composite dietary antioxidant index (CDAI) with sex hormone levels in children and adolescents. Methods: A cross-sectional analysis was conducted using data from the National Health and Nutrition Examination Survey (NHANES, 2021- 2023) of participants aged 6-19 years. Dietary intake was assessed via 24-hour dietary recall to calculate DII and CDAI. Spearman’s rank correlation was used to analyze the correlations between DII, CDAI, and sex hormone levels. Multiple linear regression models were constructed to examine the effects of DII and CDAI on sex hormone levels, with subgroup analyses conducted. Results: A total of 800 subjects were included in the study. Multiple linear regression results showed that DII was negatively correlated with the geometric means of total testosterone (TT), free androgen index (FAI), and testosterone-to-estradiol ratio (TT/E2) (Model 1, β=-0.10 to -0.21, P＜0.001). In contrast, CDAI was positively correlated with the above indicators (Model 2, β=0.02 to 0.08, P＜ 0.05). Subgroup analysis and interaction tests indicated that the associations of DII and CDAI with certain sex hormones were statistically significant among children and adolescents of different age groups. The levels of TT, FAI, and TT/E2 in the high DII + high CDAI group were significantly higher than those in the other groups (all P＜0.05). Conclusion: Dietary factors are one of the key environmental elements influencing sex hormone regulation in children and adolescents. Both dietary inflammatory and antioxidant levels collectively affect sex hormone metabolism, with developmental stage specificity. The“high-inflammatory–high-antioxidant”dietary pattern may specifically interfere with androgen metabolism, providing a basis for interventions aimed at promoting adolescent reproductive health.