Knowledge of the socio-demographic distribution of eating behaviours can aid our understanding of their contribution to the obesity epidemic and help to address healthy eating interventions to those who can benefit most. This cross-sectional study assessed the frequency of self-reported eating behaviours among 11,603 individuals representative of the non-institutionalized Spanish population aged ≥18 years in the period 2008–2010. In the adult population of Spain, 24.3% had lunch and 18.2% had dinner away from home >3 times per month. About three-fourths of adults did not plan the amount of food to be eaten, and did not choose light foods and/or skim dairy products. Also, 26% did not trim visible fat from meat, and 74.7% usually ate while watching television. Compared with individuals with primary or less education, those with university studies were more likely to remove fat from meat (age- and sex-adjusted odds ratio [aOR] 1.25; 95% confidence interval [CI] 1.08–1.44), and to choose light food and/or skim dairy (aOR 1.50; 95% CI 1.30–1.77), and less likely to eat while watching television (aOR 0.54; 95% CI 0.47–0.63). In conclusion, the prevalence of several obesity-related eating behaviours is high in Spain, which indicates a deficient implementation of dietary guidelines. Socioeconomic inequalities in eating behaviours should also be addressed.