Children with autism spectrum disorder (ASD) have a fivefold elevated risk of developing eating problems, which predisposes them to nutritional deficiencies. This study assesses nutritional intake and adequacy in children with ASD, subdiagnostic autistic symptoms and typically developing (TD) children. Preschool children with ASD and subdiagnostic symptoms had slightly lower intake of monounsaturated fatty acids (MUFA), vitamin D and vitamin B12. Primary school children with ASD and subdiagnostic symptoms had slightly higher intake of protein, cholesterol, thiamine and niacin, and a higher percentage of obesity than children with TD. All children had a high intake in sugars, fats and saturated fatty acids; a very highly inadequate intake of vitamins (vitamins D and E), fibre, b-carotene, calcium and magnesium; and a moderately inadequate intake of vitamin C, folate and iron. However, although all children need nutrition advice, children with ASD and subdiagnostic autistic symptoms had a poorer quality diet than those with TD.