There are many potential risks to withdrawing normal or regular foods, especially from young children.
Some individuals with autism already have restricted diets, are faddy eaters and so on. Exclusion diets may reinforce repetitive, rigid eating patterns, add to the social impairment of autism, increase the risk of social isolation and constraints on family life as a consequence of the dietary restrictions and increase the risk of nutritional deficiencies.
In the long term there might also be problems for the young people themselves who have conformed to the restrictions imposed by their parents' adherence to the strict diet and, as a consequence, are less willing to eat a healthy varied diet.