Sex Informed Profiles of Eating Behaviors in Autism Across Childhood and Young Adulthood - PROJECT SUMMARY Challenging or restrictive eating behaviors are well-documented in autistic individuals. Restrictive eating behaviors, such as food selectivity, refusal and neophobia occur at a greatly increased rate in autism. Eating disorders, such as anorexia nervosa, avoidant restrictive food intake disorder, and binge eating disorder, are also diagnosed at highly elevated rates in autism. However, the associations between eating behavior profiles and later clinical outcomes, such as eating disorder diagnoses, are poorly understood, with a lack of longitudinal data to meaningfully capture these trajectories. This is an urgent research need given the clinical significance of restrictive eating at a nutritional, behavioral, and social level. Given the historic sex difference in autism diagnoses, most studies fail to fully consider the role of sex on eating behaviors. However, in neurotypical populations, there are variations in challenging eating behaviors and rates of eating disorders by sex. In more recent studies, these trends have been mirrored in autistic samples The overarching goal of this NIMH R03 is to leverage data across four existing cohorts of autistic and non-autistic individuals, enriched for females and spanning a wide age range (4 to 39 years), to identify profiles of eating behaviors in autism and determine how these vary by age, and sex. Importantly, these studies all employed harmonized measures of eating behaviors to achieve a total sample size of approximately 1,200 individuals. This R03 has two aims: (1) Using latent profile analysis (LPA), characterize profiles of eating behaviors in a large sample of autistic and non-autistic individuals; and (2) Determine how profiles of eating behaviors vary by diagnosis, age, and sex. This R03 directly addresses NIMH Goal 2 to examine mental illness trajectories across the lifespan studying eating behaviors across a wide age range, spanning early childhood through to adulthood, and pan-NIH goals, including studying sex as a biological variable, and leverages samples that over-sampled for autistic females. This data driven approach will enable us to identify age-related trends in challenging eating behaviors in autism. Such data will allow us to generate hypotheses that can be tested prospectively within our ongoing NIH-funded longitudinal samples, spanning early childhood through to young adulthood, to understand the mechanisms by which challenging eating behaviors escalate to an eating disorder.