The growing number of obese children and adolescents across the world creates a diagnostic challenge to caregivers. The early clinical manifestations of abnormalities related to childhood obesity, attributed to obesity-driven insulin resistance, are impaired glucose metabolism and nonalcoholic fatty liver disease. Both have no symptoms and demand a high index of suspicion and the proper choice of tests for establishing the diagnosis. The clinician should gather information derived from thoroughly taken history and a focused physical examination to stratify patients by their risk. Focused lifestyle modification-aimed interventions are showing promising results in improving the metabolic profile of obese children. Early diagnosis may help allocate resources for intensive interventions that may benefit individuals at greatest risk for early obesity-related morbidity.