[Nonalcoholic fatty liver disease without obesity: the problem to be solved].

It is generally agreed that nonalcoholic fatty liver disease (NAFLD) is a component of metabolic syndrome and is frequently associated with obesity, type 2 diabetes mellitus, atherogenic dyslipidemia, and other components of the syndrome. However, there is no doubt that not all overweight people develop NAFLD and, conversely, the latter may be present in normal weight individuals. The prevalence of NAFLD without obesity in different countries is very variable from 3 to 30%. Its risk factors are considered to be both exogenous (for example, excess intakes of cholesterol and rapidly assimilable fructose) and genetically determined (allelic variants of the genes encoding adiponutrin, the cholesteryl ester transport protein, sterol-regulatory element-binding protein 2). The methods for the diagnosis of NAFLD without obesity do not differ in essence from those for classic NAFLD. Analysis of the conducted investigations gives grounds to claim that lifestyle modification as exercises and dietary restrictions improves biochemical parameters and histological pattern. The efficiency of drug treatments needs further investigation.