Eating Behaviours, Diet Quality and Gastrointestinal Symptoms in Children With Autism Spectrum Disorders and Typically Developing Children: a Case-control Study

To compare the differences in eating behaviours, nutritional status, diet quality and gastrointestinal (GI) health between Chinese children aged 3-6 years with autism spectrum disorders (ASD) and typically developing children (TDC).

Hypotheses:

1. Children with ASD will show more problematic mealtime behaviours as represented by higher scores of 'limited variety' and 'food refusal' domains of the BAMBI compared to typically developing children
2. Children with ASD will have more GI symptoms, in particular constipation and diarrhea compared to typically developing children
3. Children with ASD will have a lower ratio of Bacteroidetes to Firmicutes than the typical control children
4. Children with ASD will have less desirable diet quality in terms of lower dietary index, lower dietary diversity score and lower intake of fibre, iron, calcium, zinc and vitamin C compared to typically developing children
5. A better diet quality will be associated with a more favourable gut microbial composition in children with and without ASD

Design and subjects: Case-control study including 65 families with children of ASD and 65 families with TDC matched by child's age and sex.

Outcomes: The primary outcomes will be the difference in mean scores of 'limited variety' and 'food refusal' domains of the Chinese version of BAMBI between children with ASD and typically developing children. The secondary outcomes will be the difference in the occurrence of GI symptoms in terms of constipation and diarrhea, as well as the difference in the gut microbiota profile in terms of the Bacteroidetes to Firmicutes ratio between children with ASD and typically developing children. The tertiary outcome will be the difference in the diet quality in terms of lower dietary index, lower dietary diversity score and lower intake of fibre, iron, calcium, zinc and vitamin C in children with ASD and typically developing children.