Obesity: A major problem for Spanish minors

•We investigate the link between socioeconomic and demographic status and obesity prevalence in Spanish children, ages 2-15.•Overall, the observed prevalence of obesity among children aged 2-15 is 10.6%.•Obesity prevalence by age is nonlinear, increasing up to about age 5 and declining thereafter.•Obesity prevalence among children 2-15 crucially depends of income, education, diet, sleeping habits and physical activity.