To study the effects of a low free sugar diet on lipid profile, glycemic indices, liver enzymes, inflammatory factors and hepatic steatosis and fibrosis in patients with Nonalcoholic fatty liver disease, 50 patients who referred to Gastrointestinal (GI) clinic with steatosis grade 2 and 3 will be randomly allocated to receive low free sugar diet or regular diet for 12 weeks; both groups will be advised to adherence the investigators' nutrition recommendation and exercise program too. At the first and the end of the intervention, lipid profiles, liver enzymes,glycemic indices, some inflammatory markers, and liver fibrosis will be assessed and compared between groups.

Inclusion Criteria:

1. Age of 18 to 60 years
2. Body Mass Index (BMI) between 25-40
3. Sonographic findings compatible with hepatic steatosis (degree 2 or more)

Exclusion Criteria:

1. Alcohol consumption
2. pregnancy or lactation
3. Other liver disease (viral,cirrhosis,...)
4. Use of drugs such as phenytoin,tamoxifen,lithium
5. A history of Cancer, autoimmune disease,Renal disease & Celiac disease, hypothyroidism or Cushing's syndrome
6. Lack of desire to continue studying
7. Have to use antibiotics with hepatotoxic drugs while studying
8. Non-compliance with diet