Dietary modifications have been established as one of the most important strategies for population prevention of Nonalcoholic Fatty Liver Disease (NAFLD), a leading cause of chronic liver disease worldwide. Few studies have examined whether nutrient adequacy and diet quality could be associated with lower odds of risk for nonalcoholic fatty liver disease (NAFLD). The current study aimed to investigate the association of Nutrient Density and Healthy Eating Index 2015 with NAFLD in Iranian adults of the Amol Cohort Study (AmolCS).

In a cross-sectional analysis among 2956 adults (45.06% female), age ≥ 18 years (47.20±14.56), we measured usual dietary intake with a validated food frequency questionnaire (FFQ). Healthy Eating Index-2015 (HEI-2015) and nutrient-rich food index 9.3 (NRF9.3) were calculated to evaluate nutrient adequacy and diet quality. Sociodemographic and lifestyle factors were collected by a structured questionnaire. The presence and degree of NAFLD were also determined by abdominal sonography. Multiple regression models were used to estimate NAFLD odds across tertiles of NRF9.3 and HEI-2015 scores.

The multivariable-adjusting odds ratio (95% confidence interval) for the highest (vs. lowest) tertile of NRF9.3 showed an inverse association of nutrient density with NAFLD (OR=0.68, 95%CI: 0.54-0.85, Ptrend=0.001). Stratified results by gender and abdominal obesity revealed the greater nutrient adequacy was associated with lower odds of NAFLD risk in participants with abdominal obesity (OR = 0.62, 95% CI = 0.40–0.95, Ptrend = 0.03) and without abdominal obesity (OR = 0.69, 95% CI = 0.52–0.90, Ptrend = 0.007). Similar results were also obtained for nutrient adequacy and lower odds of NAFLD prevalence in both gender (in men: OR=0.68, 95%CI: 0.50-0.93, Ptrend=0.01; in women, OR=0.64, 95%CI: 0.46-0.89, Ptrend=0.01). The results of the fully adjusted multivariable model of HEI-2015, stratified by gender and abdominal obesity, revealed that the favorable association was more pronounced in participants with abdominal obesity (OR=0.63, 95%CI=0.41–0.98, Ptrend=0.03).

The results of this study showed a favorable association between nutrient adequacy and reduced risk of NAFLD in Iranian adults. The favorable association between HEI and NAFDL was more pronounced in participants with abdominal obesity. Further prospective investigations are needed to confirm the integrity of our findings.