The study in question is an interventional study with nutritional intervention. the aim of the study is to evaluate whether a diet enriched with tomatoes can have favorable effects on: * specific aspects associated with NAFLD, such as the degree of hepatic steatosis and fibrosis; * circulating levels of molecules correlated with the degree of generalized and hepatic inflammation and the blood concentrations of metabolic and cardiovascular risk factors associated with abdominal obesity; * intestinal barrier; * body composition; * intestinal microbiota; * symptoms of IBS (irritable bowel syndrome) in patients with NAFLD.