['The aim of the present study was to identify the main dietary patterns among young adults and to investigate the association of socioeconomic and demographic factors, and social mobility with dietary patterns.', 'Data from the fourth follow-up of the 1978/79 Ribeirão Preto birth cohort study, Brazil, were used. A total of 2,061 young adults, whose mothers gave sociodemographic information at birth in 1978-79, provided sociodemographic and dietary data through a validated food frequency questionnaire in 2002-2004, when they were aged 23-25 years. Those whose caloric intake was outside of the ±3 standard deviation range were excluded, leaving 2,034 individuals. The dietary patterns were identified by principal component analysis followed by varimax orthogonal rotation. Poisson regression with robust estimation of variance was used to derive prevalence ratios (PR).', 'Four dietary patterns were identified: healthy, traditional Brazilian, energy-dense and bar. In the adjusted analysis, individuals with higher schooling (≥12\xa0years) in adult life (PR\u2009=\u20091.51, 95% CI: 1.07-2.14) showed greater adherence whilst men (PR\u2009=\u20090.79, 95% CI: 0.68-0.93) had lower adherence to the healthy pattern. The highest adherence to the traditional Brazilian pattern was found for men (PR\u2009=\u20092.39, 95% CI: 2.04-2.80), mullatos (PR\u2009=\u20091.41, 95% CI: 1.21-1.64), households with ≥2 members, and for those with children (PR\u2009=\u20091.28, 95% CI: 1.07-1.55) while individuals with higher schooling in adulthood (≥12\xa0years) (PR\u2009=\u20090.47, 95% CI: 0.34-0.65), higher family income in adulthood (≥20\xa0MW) (PR\u2009=\u20090.57, 95% CI: 0.33-0.99) and higher family income at birth (≥6.1\xa0MW) showed lower adherence. The bar pattern was positively associated with male sex (PR\u2009=\u20092.96, 95% CI: 2.47-3.55) and low schooling (≤8\xa0years). The energy-dense pattern was not associated with any of the variables investigated. Social mobility was associated with the traditional Brazilian pattern. Men and women who were not poor at birth and remained so in adulthood showed lower adherence to this pattern (PR\u2009=\u20090.70, 95% CI: 0.53-0.94 for men and PR\u2009=\u20090.40, 95% CI: 0.20-0.80 for women).'] Are socioeconomic and demographic factors associated with dietary patterns in a cohort of young Brazilian adults?