Ultra-processed food consumption and the risk of non-alcoholic fatty liver disease in the Tianjin Chronic Low-grade Systemic Inflammation and Health Cohort Study

Background Growing evidence supports a link between ultra-processed food consumption and human health outcomes. However, the association between ultra-processed food consumption and non-alcoholic fatty liver disease (NAFLD) is not known. We aimed to explore the association between ultra-processed food consumption and risk of NAFLD. Methods The prospective study included 16 168 participants aged 18-90 years from the Tianjin Chronic Low-grade Systemic Inflammation and Health (TCLSIH) Cohort Study. Information on ultra-processed food consumption was collected at baseline using a validated food frequency questionnaire. NAFLD was defined as the presence of sonographic fatty liver in the absence of significant alcohol intake (>= 210 g/week for men and >= 140 g/week for women, respectively) and other liver diseases. Multivariable Cox proportional hazards models were used to examine the association between ultra-processed food consumption and risk of NAFLD. Results During 56 935 person-years of follow-up, we documented 3752 incident NAFLD cases. After adjusting for age, sex, body mass index, smoking, alcohol drinking, education, occupation, income, physical activity, total energy intake, personal and family history of disease and overall diet quality, the multivariable hazard ratios (95% confidence interval) of NAFLD across increasing quartiles of ultra-processed food consumption were 1.00 (reference), 0.99 (0.90, 1.08), 1.13 (1.03, 1.25) and 1.18 (1.07, 1.30), respectively (P for trend <0.0001). The hazard ratio (95% confidence interval) per one standard deviation increase in ultra-processed food consumption, equivalent to a 62.7 g/1000 kcal per day, was 1.06 (1.03, 1.09), P = 0.0001. Conclusions Our study indicates that higher ultra-processed food consumption is associated with a higher risk of NAFLD. This finding suggests that ultra-processed food, which is widely consumed worldwide, might be a modifiable dietary target to reduce the risk of NAFLD.