Effect of 6-month nutritional intervention on non-alcoholic fatty liver disease.

Objective: We evaluated the effect of diet therapy as exclusive treatment on insulin resistance, biochemical parameters of metabolic syndrome, and degree of hepatic steatosis in patients with non-alcoholic fatty liver disease.

Methods: Thirty-one patients with non-alcoholic fatty liver disease received a diet with a reduction of 500 to 1000 cal/d, containing 15% protein, 55% carbohydrates, and 30% fat, for 6 mo. At entry and 6 mo after dietary instructions, degrees of hepatic steatosis and visceral obesity were assessed by computed tomography; serum aspartate aminotransferase, alanine aminotransferase, γ-glutamyl transferase, glucose, triacylglycerols, and high-density lipoprotein cholesterol were measured by automated methods. Body mass index, waist circumference, waist-to-hip ratio, and food intake (7-d diary) were also evaluated. At the end of follow-up, the patients were classified as adherent or non-adherent to treatment according to a weight loss of more or less than 5% of initial body weight, respectively.

Results: Seventeen patients were classified as adherent (group 1) and 14 as non-adherent (group 2). Group 2 only presented a significant reduction in body mass index and waist circumference. In contrast, in group 1, in addition to significant improvement of all anthropometric parameters, a significant reduction was observed in alanine aminotransferase and γ-glutamyl transferase levels, homeostasis model assessment for insulin resistance, visceral fat and tomographic liver density, together with an increase in serum high-density lipoprotein cholesterol levels. These patients presented a significant decrease in total energy intake and in total and saturated fats.

Conclusion: Nutritional intervention as exclusive treatment, with a loss of at least 5% of initial weight, is effective in the treatment of non-alcoholic fatty liver disease.