Non-invasive diagnosis and treatment of nonalcoholic fatty liver disease (NAFLD) remain unmet medical needs. Aim of this study is to investigate the blood levels of three hormonal systems related to obesity, insulin resistance and inflammation in patients with different stages of NAFLD, in order to identify potential diagnostic markers. Study aim: To compare the blood levels of: a) proglucagon-derived hormones (glucagon-like peptide \[GLP\]-1, GLP-2, glicentin, oxyntomodulin, glucagon, major proglucagon fragment \[MPGF\]), b) follistatins-activins (follistatin-like (FSTL)3, activin B), c) IGF axis (insulin-like growth factor (IGF)-1, total and intact IGF binding protein (IGFBP)-3 and IGFBP-4, in 18 individuals with early stage NAFLD vs. 14 controls To explore the levels of GDF-15, total and intact, in NAFLD versus obese controls (OC) at baseline and during oral glucose tolerance tests (OGTTs)