Crosstalk between dietary patterns, obesity and nonalcoholic fatty liver disease

Abstract

The prevalence of nonalcoholic fatty liver disease (NAFLD) is rising worldwide, paralleling the epidemic of obesity. The liver is a key organ for the metabolism of proteins, fats and carbohydrates. Various types of fats and carbohydrates in isocaloric diets differently influence fat accumulation in the liver parenchyma. Therefore, nutrition can manage hepatic and cardiometabolic complications of NAFLD. Even moderately reduced caloric intake, which leads to a weight loss of 5%-10% of initial body weight, is effective in improving liver steatosis and surrogate markers of liver disease status. Among dietary patterns, the Mediterranean diet mostly prevents the onset of NAFLD. Furthermore, this diet is also the most recommended for the treatment of NAFLD patients. However, clinical trials based on the dietary interventions in NAFLD patients are sparse. Since there are only a few studies examining dietary interventions in clinically advanced stages of NAFLD, such as active and fibrotic steatohepatitis, the optimal diet for patients in these stages of the disease must still be determined. In this narrative review, we aimed to critically summarize the associations between different dietary patterns, obesity and prevention/risk for NAFLD, to describe specific dietary interventions’ impacts on liver steatosis in adults with NAFLD and to provide an updated overview of dietary recommendations that clinicians potentially need to apply in their daily practice.

Keywords: Nonalcoholic fatty liver disease; Dietary patterns; Obesity; Diet; Mediterranean diet; Nutrition; Treatment; Clinical guidance

Core Tip: In this review, we emphasize that based on the current evidence, there is no consensus on the ideal macronutrient composition of the diet for nonalcoholic fatty liver disease (NAFLD) patients. We have shown that dietary habits are the most important factor in NAFLD prevention. The Mediterranean and healthy dietary pattern, characterized by high consumption of vegetables, fruits, nuts, olive oil, low-fat dairy products and fish, were linked with a reduced NAFLD risk. The Dietary Approach to Stop Hypertension diet, intermittent fasting and ketogenic diet are other dietary regimes that have growing interest among specialists who advise patients with NAFLD. Nevertheless, new studies designed to assess the effects of these diets on liver-related outcomes and liver histology are needed. We also noted that dietary advice should be personalized in NAFLD patients.