OBJECTIVE: Pediatric chronic illnesses (CI) can affect a child's mental health. Chronic illnesses with treatment regimens that specify a therapeutic diet may place the child at increased risk for disordered eating and specific eating disorders (ED). The aim of this review is to examine the relation between diet-treated CI and disordered eating and to determine the order of onset to infer directionality. Diet-treated CI is hypothesized to precede and to be associated with disordered eating. METHOD: A comprehensive search of empirical articles that examine the relation between diet-treated CI (diabetes, cystic fibrosis, celiac disease, gastrointestinal disorders, and inflammatory bowel diseases) and disordered eating was conducted in Medline and PsycINFO using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A table of the sample's characteristics, ED measures, major pertinent findings, and the onset of CI in relation to ED were provided. RESULTS: Diet-treated CI was associated with disordered eating and ED. Diet-treated CI had onset prior to disordered eating in most studies, except for inflammatory bowel diseases. Disordered eating and unhealthy weight management practices put children at risk for poor medical outcomes. DISCUSSION: Interventions for diet-treated CI require a focus on diet and weight, but may increase the risk for disordered eating. Future research is needed to elucidate the mechanisms that transform standard treatment practices into pathological eating, including characteristics and behaviors of the child, parents/care providers, family, and treatment providers.