Azam Doustmohammadian, Bahareh Amirkalali, Ali Gholami, Minoo Hasan Rashedi, Mohammad Farahmand, Fateme Sheikholmolooki, Mohadeseh Sedighi
Journal: Frontiers in nutrition 2025;12():1596300
PMID: 40626217
Chronic inflammation may contribute to the development of non-alcoholic fatty liver disease (NAFLD). Adopting an anti-inflammatory diet may help prevent or manage NAFLD. This was a systematic review and meta-analysis of 11 observational studies that investigated the link between the Dietary Inflammatory Index (DII) and the risk of NAFLD, a condition where excess fat builds up in the liver without alcohol consumption to determine if a diet that lowers inflammation could lower risk of disease.
The results showed that inflammatory diets were associated with a higher risk for NAFLD.
It was concluded that diets that rate highly on the DII are associated with an increased risk for NAFLD. This study could be used by healthcare professionals to understand the potential impact of an anti-inflammatory diet on reducing the risk of non-alcoholic fatty liver disease.
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Diets high in pro-inflammatory foods are associated with a greater likelihood of developing NAFLD.
Eating patterns rich in anti-inflammatory foods such as fruits, vegetables, whole grains, legumes, nuts, and olive oil, may help support liver health.
This meta-analysis was of observational studies assessed as very low evidence certainty using the GRADE framework. It therefore has limitations and is unable to preclude causal relationships between NAFLD and DII.
Introduction
This study aimed to examine the association between the Dietary Inflammatory Index (DII) and non-alcoholic fatty liver disease (NAFLD) risk.
Methods
This was a meta-analysis of eleven observational studies amongst which nine were cross-sectional ( n= 82,974) and two cohort ( n= 184,421) studies. It followed the PRISMA guidelines and is registered with PROSPERO.
Results
Overall study quality was acceptable, with most included studies rated as moderate to high quality, strengthening confidence in the observed associations despite inherent limitations of observational designs.
Results showed that:
higher DII scores were associated with significantly greater NAFLD risk in cross-sectional studies (OR = 1.56; 95% CI 1.24–1.95; p < 0.001; I² = 86.9%).
cohort studies showed a significant association between dietary inflammatory potential and NAFLD incidence (HR = 0.21; 95% CI 0.12–0.30; p < 0.0001), reflecting lower risk among individuals with less pro-inflammatory diets.
subgroup analyses (body mass index, age, region, NAFLD diagnostic method, DII scoring approach) consistently supported the association between higher DII and increased NAFLD risk (all p < 0.05).
certainty of evidence was rated as very low due to high heterogeneity, observational study designs, and variation in exposure and outcome measurements.
Conclusion
The authors concluded that higher DII scores are associated with increased NAFLD risk.
Reducing the inflammatory potential of the diet, by increasing anti-inflammatory foods (e.g., fruits, vegetables, whole grains, omega-3 rich foods) and limiting pro-inflammatory items (e.g., refined carbohydrates, processed meats and added sugars), may help lower NAFLD risk in at-risk individuals.
Incorporating DII-based dietary assessment tools into routine nutritional evaluations may support early identification of individuals consuming highly pro-inflammatory diets.
Longitudinal cohort studies and well-designed randomised controlled trials are needed to clarify causal relationships between dietary inflammatory potential and NAFLD risk.
Future studies should standardise DII assessment methods and NAFLD diagnostic criteria to improve comparability across populations and research settings.
Reducing publication bias through comprehensive reporting and inclusion of null findings will help strengthen the reliability of the overall evidence base.
AIM
Chronic inflammation plays a significant role in the progression of non-alcoholic fatty liver disease (NAFLD). Adopting an anti-inflammatory diet can help prevent or mitigate NAFLD and its associated complications. This meta-analysis builds on previous research by examining the association between the Dietary Inflammatory Index (DII) and NAFLD risk, incorporating additional studies and employing rigorous evidence assessment.
METHODS
We systematically searched major databases (Cochrane Library, PubMed, Web of Science, and Scopus) from inception to June 2024 for English-language observational studies examining the association between DII and NAFLD prevalence. Pooled odds ratios (ORs) or hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated using random-effects models for studies with significant heterogeneity; otherwise, fixed-effects models were applied. Subgroup analyses were conducted to explore heterogeneity based on body mass index (BMI), DII definition, sample size, geographical region, age, and NAFLD diagnostic criteria. Evidence certainty was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework. The study was registered in PROSPERO (CRD42023430798).
RESULTS
Eleven studies (9 cross-sectional with 14 effect sizes and 2 cohort with 2 effect sizes) were analyzed. Higher DII scores were significantly associated with increased NAFLD risk, with a pooled OR of 1.56 (95% CI: 1.24-1.95; < 0.001) in cross-sectional studies and an HR of 0.21 (95% CI: 0.12-0.30; < 0.0001) in cohort studies. Subgroup analyses confirmed consistency across BMI ≥ 25, energy-adjusted DII or DII, studies in Asia and Europe, and participants <46 years, with reduced heterogeneity (I < 50%) in these categories. GRADE rated the certainty of evidence as "very low."
CONCLUSION
Anti-inflammatory diets can reduce NAFLD risk. However, high-quality studies are needed to confirm this association.
Copyright © 2025 Amirkalali, Farahmand, Rashedi, Gholami, Sheikholmolooki, Sedighi and Doustmohammadian.
© Copyright 2026, Nutrition Evidence
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