AbstractObjectiveSocioeconomic mobility, i.e., changing socioeconomic status (SES) between adolescence and adulthood, may impact health through changing resources, social status, and health‐related behaviors. This analysis examined whether subjective SES contributes to associations of mobility with metabolic health (BMI and metabolic syndrome) and unhealthy diets (fast‐food consumption and sugar‐sweetened beverage [SSB] consumption).MethodsNational Longitudinal Study of Adolescent to Adult Health data were used (n = 4132). Mobility was defined as the difference between adolescent (collected 1994–1995, ages 11–19 years) and adult (collected 2016–2018, ages 33–43 years) SES. Linear and logistic regressions examined associations of mobility with metabolic and dietary outcomes and mediation by subjective SES.ResultsSubstantial upward mobility was associated with lower risk of high SSB consumption compared with stable disadvantaged SES (risk difference: −0.10 [95% CI: −0.16 to −0.041]). Subjective SES mediated associations of upward, but not downward, mobility with risks of developing metabolic syndrome, high fast‐food consumption, and high SSB consumption; upward mobility was associated with higher subjective SES and lower risks of poor metabolic and dietary outcomes.ConclusionsThe finding that subjective SES contributed to associations between upward mobility and better health may inform development of interventions designed to promote healthier diets and reduce socioeconomic disparities in metabolic health.