Association between Ultra-processed Food Consumption And Mortality among U.S. Adults: Prospective Cohort Study of the National Health And Nutrition Examination Survey 2003-2018

Background: Intake of ultra-processed foods provides more than half of the daily energy U.S. adults consume. Still, the prospective association of ultra-processed food consumption with mortality in the general U.S. population remains understudied.

Objective: To investigate the prospective association of ultra-processed food consumption with mortality in a nationally representative sample of U.S. adults.

Design: A prospective cohort analysis was conducted by linking baseline measurement from the National Health And Nutrition Examination Survey (NHANES) with mortality information from the National Death Index. The percentage of total energy (%E) consumed from ultra-processed foods, defined by the Nova classification system, was computed based on dietary data collected using 24-hour diet recalls.

Participants/setting: This study included 38148 nationally representative U.S. adults aged 20 years and above who participated in NHANES between 2003-2004 to 2017-2018 and provided dietary intake data, with linkage to mortality data.

Main outcome measures: Information on all-cause and cause-specific mortality was obtained from linkage to the National Death Index through December 31, 2019.

Statistical analysis performed: Cox proportional hazard models estimated the multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between ultra-processed food intake and mortality.

Results: During a median follow-up of 8.0 years, 4,611 deaths were confirmed, including 2064 deaths from cardiometabolic disorders (CMD) and 1046 deaths from cancer. After multivariable adjustments, each 10-point increment in usual %E from ultra-processed foods was associated with a 9% higher risk of all-cause mortality (HR=1.09, 95% CI, 1.04-1.14). The association remained significant after adjusting for the overall diet quality measured by the Health Eating Index 2015 (HR=1.06, 95% CI, 1.00-1.11, P<0.05). Among subgroups, sugar-sweetened beverages, ready-to-eat or -heat mixed dishes, ultra-processed dairy products, and ultra-processed oil/fat, condiments, and sauces were associated with an increased risk of all-cause or cause-specific mortality. Ultra-processed vegetables and legumes were associated with a reduced risk.

Conclusions: In this nationally representative study of U.S. adults, higher consumption of ultra-processed food was associated with a higher risk of all-cause mortality, and this association was not fully explained by overall diet quality.