This study has examined bio-socio-demographic and psychopathological factors probably associated with unhealthy eating patterns among university students and to estimate a multifactorial model following the associated factors by gender. Adjusted odds ratios were calculated to describe associations on basis of Eating Disorder Inventory (EDI) stratified by gender in a representative sample of Spanish university students (n = 2551). The high EDI scorers for both sexes presented higher prevalence of dieting, body dissatisfaction, levels of psychopathology and lower self-esteem than the low EDI scorers. The results suggest that older students and higher self-esteem scores present lower scores in the EDI. In the female population, depression, paranoid dimension, dieting and body dissatisfaction were associated with population with unhealthy eating patterns. In the male sample, dieting, body dissatisfaction and interpersonal sensibility were also associated with unhealthy eating patterns. The results corroborate that abnormal eating patterns tend to affect specific vulnerable groups. We do not know the precise mechanisms through which these risk behaviors and attitudes, such as dieting or body dissatisfaction, may facilitate the later development of an eating disorder.