Autism is a lifelong condition characterised by difficulties with social interaction, social communication and repetitive behaviours. In recent decades, the number of children and adults diagnosed with autism has increased. As autism is heritable, genetic risk may explain why there are some individuals with mild autistic traits but they may not meet the criteria for an autism diagnosis and subsequent treatment or other support requirements. As more children with autism and mild autistic traits reach adulthood, the need for support from health and other services will likely increase. However, few large, population based longitudinal studies involving adults with autism/autistic traits exist, representing a research gap.

During this phase of my PhD project, I will study how autism and autism traits, including genetic risk for autism, may be associated with BMI and disordered eating behaviours in adulthood. Children with autism often having sensory issues and unusual eating preferences, which could have an effect on growth and health in adult life. It has been reported that social communication difficulties may increase the risk of disordered eating patterns in adolescence. This implies that maintaining a healthy BMI may be challenging during this period and that there is a possible increased risk of disordered eating behaviours and eating disorders in adulthood for those with social communication difficulties. This phase of my PhD project is focussed on whether autistic individuals are more likely to have high BMI and disordered eating behaviours in adulthood. Changes in growth during late childhood into late adolescence will also be studied to assess whether there are critical periods that are suitable for intervention.