Gluten and casein free diets in autism: a study of the effects on food choice and nutrition.

Background  There is growing interest in possible dietary involvement in the aetiology and treatment of Autistic Spectrum Disorders (ASD). Research has focused on the physiological and behavioural effects of dietary change but has not examined the effect of exclusion diets on nutritional intake. Aims  The aim of this study was to examine whether the removal of major dietary staples placed children with autism at risk of nutrient deficiency and compares their food choice with ASD children not following gluten and/or casein free diets. Methods  A postal questionnaire was sent to parents of children aged 3–16 years, diagnosed with ASD belonging to the National Autistic Society in Leicestershire and southern Derbyshire. Detailed dietary information and a 3-day food diary were collected. The sample size was small: those using gluten/casein free diets (n = 8) and those not following diet (n = 29). Results  Nutrient intakes fell below the Lower Reference Nutrient Intake (LRNI) in 12 children (32%) for zinc, calcium, iron, vitamin A, vitamin B12 and riboflavin in the nondiet group and four children (50%) for zinc and calcium in the diet group. Fruit and vegetable intakes were higher and cereal, bread and potato consumption were lower in those children using gluten and/or casein free diets. Conclusion  No significant differences in the energy, protein and micronutrient intakes were found between the two groups of children. A longitudinal prospective study is suggested to examine whether differences in food choice are the result of dietary intervention or the prerequisite for the successful application of diet in this special group of children.