New Obesity Definitions Reclassify Many MASLD Patients but Do Not Improve Liver Risk Prediction

• New obesity definitions from EASO and the Lancet Commission reclassified 20.4% and 34.1% of MASLD patients as obese who were non-obese by BMI alone.

• These newly classified obese groups did not have a significantly higher risk of liver-related events compared with non-obese patients (adjusted SHR 1.15 and 0.75, respectively).

• Risk of liver-related events increased meaningfully only when waist-to-height ratio approached 0.6, suggesting higher thresholds may be needed.

• BMI alone remains a comparable predictor of liver outcomes in MASLD, and new definitions broaden the obesity population without improving risk stratification.

Study Snapshot

• Design: Multinational cohort study using the VCTE-Prognosis cohort.

• Population: 12,583 patients with metabolic dysfunction-associated steatotic liver disease (MASLD).

• Exposure: Obesity defined by three frameworks: BMI alone, EASO criteria (BMI obesity or overweight with WHtR ≥0.5 plus comorbidity), and Lancet Commission criteria (BMI obesity plus ≥1 elevated anthropometric measure, or ≥2 elevated measures, or BMI ≥40 kg/m²).

• Primary Outcome: Liver-related events (LRE) incidence per 1,000 person-years.

• Key Result: LRE incidence was 2.4 (normal weight), 3.4 (overweight), 5.2 (obese) per 1,000 person-years by BMI. New definitions did not improve LRE prediction (aSHR 1.15 for EASO reclassified; 0.75 for Lancet reclassified).