Dietary Determinants of Non-Alcoholic Fatty Liver Disease in Lean and Non-Lean Adult Patients: A Population-Based Study in Shiraz, Southern Iran

Background Dietary components predisposing to non-alcoholic fatty liver disease (NAFLD) have been conflicting to date. This study aimed to compare macro and micronutrients and food intake among non-lean and lean patients with NAFLD. Methods Adult people older than 18 years from seven postal districts of Shiraz, Iran, were selected using multistage cluster randomized sampling. Nutrition status was queried by a standard food frequency questionnaire and NAFLD was detected by sonography. The participants were divided into four groups: non lean-NAFLD (participants with NAFLD and BMI ≥ 25 kg/m²), lean-NAFLD (participants with NAFLD, BMI < 25 kg/m²), Non lean-Non NAFLD (BMI ≥ 25 kg/m² without NAFLD), lean-non NAFLD (BMI < 25 kg/m² without NAFLD). Results Of 478 participants, 204 (42.7%) were lean and 95 (19.9%) were diagnosed with NAFLD. The median age of interviewees was 42 years and male to female ratio was 0.7. Overall, starchy foods and potato intake was significantly different between the groups. In non-lean group, potato intake was higher among NAFLD compared to non-NAFLD (P = 0.02) individuals and in lean group, total starchy food intake was higher in those with NAFLD compared to the counterpart group (P = 0.02). Our study revealed that after adjusting for confounders, for each gram increase in carbohydrate intake, the chance of NAFLD increased by 1.99 times (95% CI: 1.982 - 1.997; P = 0.004). Also, for each gram increase in potato consumption, the risk of the disease increased by more than 2.5-fold (OR = 2.584; 95% CI: 1.281 - 5.213, P = 0.008). Moreover, NAFLD had an association with the intake of fat and the intake of polyunsaturated fatty acids (P = 0.01 and P = 0.02, respectively). Conclusions Besides studying NAFLD in obese patients, lean NAFLD patients should not be neglected and more studies should be conducted to assess their dietary intake. It seems greater attention should be given to fat and starches than before in order to prevent the rising trend of NAFLD in population.