Normal body weight does not guarantee protection from fatty liver disease

Published October 28, 2026 · Large retrospective observational analysis · Risk stratification, not causal treatment evidence
Primary source: Normal-BMI MASLD study, PMID 42947552

Clinicians often equate metabolic dysfunction-associated steatotic liver disease with obesity. An analysis of a U.S. electronic health-record network included 619,171 patients, creating 51,940 matched pairs with normal-BMI and overweight/obesity-associated MASLD under ethnicity-informed BMI definitions.

Reported survival was 77.49% in the normal-BMI MASLD group versus 83.93% in the comparator group, corresponding to a mortality hazard ratio 1.735 (95% CI 1.653–1.822). The authors also reported differences in certain cardiovascular, renal, and cancer outcomes across ethnic groups. Incretin-based treatment was used less frequently in the normal-BMI group, and its use correlated with better survival.

Strength and limitations. Large datasets and matching help identify a potentially overlooked population, but coding, residual confounding, selection, disease-severity imbalance, and care-access differences can distort the comparisons. An association between incretin use and survival is not evidence that these medicines should be prescribed to normal-BMI MASLD patients for longevity.

Clinical practice: Evaluate steatotic liver disease and metabolic risk on their own merits, not BMI alone.