This study aims to determine the short-term longitudinal relationship between FGF21, adiponectin and liver fat and to investigate the role of FGF21-Adiponectin Ratio (FAR) as a potential marker to monitor change in liver fat percent (as assessed by MRI) in obese children and adolescents at risk for NAFLD. This evidence concerns the gene FGF21 and metabolic dysfunction-associated steatotic liver disease.