BackgroundRecent studies have emphasized the intricate relationship between obesity and psychological distress, unraveling the complex interplay of biological, psychological, and sociocultural factors. However, a conspicuous knowledge gap persists in understanding the association between obesity severity and psychological distress, particularly in young adults, marked by limited empirical data. ObjectivesThis study comprehensively investigates the link between obesity and psychological distress among young adults, emphasizing potential variations based on gender and race or ethnicity. Addressing this gap is crucial for informing targeted interventions and understanding the nuanced impact of obesity on mental health in this demographic. MethodsUtilizing data from the 2013 to 2018 National Health Interview Survey, individuals aged 18 to 26 years were analyzed. Body mass index served as the primary exposure variable, with the Kessler Psychological Distress Scale assessing the primary outcome. Fully-adjusted ordinal regression models were employed for analyses. ResultsAmong the 20,954 participants included in this study, representing 35,564,990 adults, 27% were overweight and 24% had obesity. In class III obesity, individuals experienced 1.4 times more psychological distress than those with normal weight (OR: 1.393; 95% CI: 1.181-1.644; P < 0.001). Subgroup analyses revealed consistent trends in non-Hispanic White (OR: 1.615; 95% CI: 1.283-2.032; P < 0.001) and female participants (OR: 1.408; 95% CI: 1.408-2.096; P < 0.001). ConclusionsThis study underscores the association between obesity and psychological distress in young adults, notably impacting non-Hispanic White and female populations. The findings bear significant implications for shaping future health policies, addressing the mental health crisis, and mitigating the increasing prevalence of obesity among young U.S. adults.