Effects of the interaction between body mass index and dietary patterns on severe NAFLD incidence: A prospective cohort study

Abstract

Background: It remains unclear whether the associations between dietary patterns and non-alcoholic fatty liver disease (NAFLD) vary by body mass index (BMI). We aimed to explore the association between dietary patterns and severe NAFLD incidence, and further investigate the interaction of BMI with dietary patterns.

Methods: In a prospective cohort study using UK Biobank data, we included White participants with baseline food frequency questionnaire (FFQ) information. Principal component analysis (PCA) with varimax rotation was performed to identify major dietary patterns. The primary outcome was severe NAFLD, defined as hospitalization due to NAFLD or non-alcoholic steatohepatitis (NASH). We employed cause-specific Cox regression for competing risks to assess the association and calculated the relative excess risk due to interaction (RERI) to estimate the interaction of BMI.

Results: This study included 307,130 participants with a median follow-up of 12.68 years. 3104 cases of severe NAFLD were identified. PCA analysis revealed two primary dietary patterns: a prudent diet (RC1) and a meat-based diet (RC2). Multivariate analysis showed a standard deviation (SD) increase in RC1 was associated with lower severe NAFLD risk (HR 0.91 [95 % CI 0.88 to 0.94]), while a SD increase in RC2 was associated with higher risk (1.10 [1.05 to 1.14]). Significant interactions were observed between baseline BMI ≥25 kg/m² and dietary patterns (RC1: RERI: -0.22 [95 % CI -0.43 to -0.003]; RC2: 0.29 [0.03 to 0.56]).

Conclusions: Targeted dietary modifications are vital for specific populations at risk of severe NAFLD, considering the significant interaction observed between BMI and dietary patterns.

Keywords: BMI; Dietary pattern; Interaction effect; NAFLD; Prospective cohort.