Bioactive peptides are related to the prevention and treatment of many diseases. GPETAFLR is an octapeptide which was isolated from lupine (Lupinus angustifolius L.) and showed anti-inflammatory properties. The aim of this study was to evaluate the potential activity of GPETAFLR to prevent non-alcoholic fatty liver disease (NAFLD) in high-fat diet (HFD)-induced obese mice. C57BL/6J mice were fed a standard diet or an HFD. Two of the groups fed the HFD diet were treated with GPETAFLR in their drinking water at 0,5 mg/kg/d or 1 mg/kg/d. To determine the ability of GPETAFLR to improve the onset and progression of NAFLD, histological studies, hepatic enzyme profile, inflammatory cytokine and lipid metabolism-related genes and proteins were analyzed. Our results suggest that HFD-induced inflammatory metabolic disorders were alleviated by treatment with GPETAFLR. In conclusion, dietary lupine consumption could repair HFD-induced hepatic damage, possibly via modifications in the liver’s lipid signalling pathways.