In a case-control study of 675 Iranian adults (225 NAFLD cases, 450 controls), those scoring in the highest tertile of the Cardiovascular Health Diet Index (CHDI) had 84% lower odds of non-alcoholic fatty liver disease compared to the lowest tertile (OR = 0.16; 95% CI: 0.08–0.32). The Concise Healthy Diet Score (CHDS) showed a similar pattern: highest-category adherents had 69% lower NAFLD odds (OR = 0.31; 95% CI: 0.17–0.60). Each one-unit CHDI increase corresponded to an 8% odds reduction, with associations holding after multivariable adjustment for standard confounders.
NAFLD now affects roughly 25–30% of adults globally and sits upstream of cirrhosis, hepatocellular carcinoma, and cardiovascular mortality — making dietary prevention a high-value target. The CHDI was originally designed to capture cardiovascular-protective eating patterns (emphasizing fruits, vegetables, whole grains, legumes, fish, and limited saturated fat and sodium), so its association with liver health is biologically plausible: shared pathways involve insulin resistance, visceral adiposity, and hepatic lipogenesis. The effect sizes here are striking — perhaps too striking. Case-control designs are vulnerable to recall bias and reverse causation; NAFLD patients may have already modified their diet post-diagnosis. The Middle Eastern study population also limits generalizability. Still, the finding adds to a growing body of evidence that overall diet quality, rather than individual nutrients, is the lever worth pulling for metabolic liver disease. Clinicians counselling patients on NAFLD prevention have strong cumulative reason to recommend cardiovascular-style dietary patterns.