Brief Summary: Eating problems and in particular food selectivity is a condition that worsens a long-life disorder such as Autism Spectrum Disorder (ASD) , both on an individual level, both on family and social ones . Children (2-6 years) diagnosed with ASD according to Diagnostic and Statistical Manual of Mental Disorders 5 Edition (DSM5) criteria were enrolled in an observational, cross-sectional and multicentric study conducted by three different Italian clinical centers. Regarding this sample, principal aims of the study are to describe characteristics of food selectivity, to evaluate its correlation with ASD symptoms, with cognitive and adaptive functioning of ASD preschoolers, to describe its impact on parental stress.