Dietary Treatment of Nonalcoholic Steatohepatitis

Emily R. Perito; Luis A. Rodriguez; Robert H. Lustig


Curr Opin Gastroenterol. 2013;29(2):170-176. 

In This Article

Carbohydrate Restriction for Treatment of Nonalcoholic Steatohepatitis

There are few studies that directly compare different diets for NASH treatment. In the largest randomized trial, with 170 overweight adults, 6 months of a low-fat or low-carbohydrate diet produced equivalent reductions in intrahepatic fat, ALT, visceral adiposity, total weight and insulin sensitivity.[38] A 3-month study similarly found that low-carbohydrate and low-fat diets reduced ALT to a similar degree.[39]

Other studies suggest that carbohydrate-restricted diets might be more beneficial for reducing surrogate markers of NAFLD than fat-restricted diets. In a small study, Kirk et al. compared a low-carbohydrate with a low-fat diet. Both decreased body weight by approximately 7%. The low-carbohydrate diet decreased intrahepatic fat significantly more after 48 h (-30 vs. -10%), but the diets led to equal decreases in liver fat after 11 weeks (-38 vs. -42%). Neither diet changed aspartate aminotransferase nor ALT[40] In a carbohydrate overfeeding paradigm that induced NAFLD, weight loss did reverse the hepatic steatosis.[41]

Two posthoc analyses of prospective trials found that low-carbohydrate diets were associated with larger reductions in ALT than low-fat diets. In one study,[42] after 18 weeks, serum ALT concentrations decreased twice as much in the low-carbohydrate group, a significant difference even after adjusting for ALT, sex, age and weight loss. Another prospective study followed three groups of type 2 diabetics over 12 months, on one of three diets: American Diabetes Association [60% carbohydrate (CHO), 20% fat]; low glycemic index (50–55% low glycemic index CHO, 30% fat); or modified Mediterranean index (35% low glycemic index CHO, 45% high monounsaturated fat). ALT decreased in all three groups, with the greatest decrease in those on the low-carbohydrate modified Mediterranean diet, from 25 U/l at baseline to 14 U/l at 12 months.[43]