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.