Implications of diet on nonalcoholic fatty liver disease.

PURPOSE OF REVIEW: This review examines the effects of diet on nonalcoholic fatty liver disease (NAFLD). This includes the effects of calories, both in excess and restricted, as well as macronutrients.

RECENT FINDINGS: Recent findings suggest that short-term hypercaloric feeding leads to increased intrahepatic triglyceride (IHTG), whereas short-term hypocaloric feeding leads to decreased IHTG, despite little change in total body weight, suggesting that ongoing excess caloric delivery directly contributes to the development of NAFLD. Weight loss with either low-fat or low-carbohydrate diets can improve IHTG; however, specific macronutrients, such as fructose, trans-fatty acids, and saturated fat, may contribute to increased IHTG independent of total calorie intake. n-3 polyunsaturated fatty acids and monounsaturated fatty acids may play a protective role in NAFLD. The mechanisms behind these effects are not fully understood.

SUMMARY: Diet plays a role in the pathophysiology of NAFLD. It is reasonable to advise patients with NAFLD to reduce calorie intake with either low-fat or low-carbohydrate diets as well as limit intakes of fructose, trans-fatty acids, and saturated fat.