The aim of this study is to examine the effect of two isocaloric energy-restricted diets on non-alcoholic fatty liver disease patients. Maximum 40 Patients using NAFLD Registration research data file in Tabriz university who would like and have not diseases like renal and pulmonary diseases,…and not use hepatotoxic drugs and with moderate activity level will be selected. Patients will be randomly allocated into two diets with considering BMI and sex matching. Diet1 and Diet2 will be followed for 6 weeks. Daily energy requirement will be estimated based on age, sex, height, ideal body weight and physical activity level. Diets will be as follows: Diet 1: C 55%, F 25%, P 20% and Diet 2: C 40%, F 40% and P 20%. After the 6-week period, patients will start a 14-day washout period and then, in a cross-over manner, patients will be switched for the second 6-week period. Three days weighing food record questionnaires will be fulfilled. Obesity indices (inc. Body mass index, waist circumference , waist to hip ratio), fasting levels of ALT, AST, ALP, lipid profiles (inc. TC, HDL-C, LDL-C, TG, LP(a)), insulin resistance and liver echogenicity using sonography will be assessed at baseline, and end of each period.