Objective <p>To develop and validate Obesity Interpreter, a mobile application tool to assist in assessing children with obesity and avoid unwarranted workup in physiological obesity.</p> Methods <p>The Obesity Interpreter offers guidance on probable diagnoses and workup based on clinical inputs. The validation involved comparing the guidance from the Obesity Interpreter, a pediatric endocrinologist, a pediatrician, and a trainee on the final diagnosis (gold standard) in 400 children and adolescents with obesity concerns (270 constitutional, 23 genetic/syndromic, 11 drug-induced, 13 endocrine, 83 normal or overweight).</p> Results <p>The concordance scores were higher for the endocrinologist (92.1%) and the Obesity Interpreter (99.5%) compared to the pediatrician (75.4%) and the trainee (56.6%). The workup guidance of the Obesity Interpreter aligned with the gold standard in 398 (99.5%) subjects (Cohen’s kappa 0.989, 95% CI 0.971, 1.0). Diagnostic workup discrepancies were noted in 83 (20.8%) subjects by the pediatrician and in 162 (40.5%) subjects by the trainee. Utilizing the mobile application would have prevented 288/ 292 (98.6%) errors observed in the study with high agreement for classification recommendation (Cohen’s kappa 0.990, 95% CI 0.975, 1.0).</p> Conclusion <p>Obesity Interpreter provided guidance aligned with the gold standard for evaluation of children with obesity.</p>