Trends in Adults' Intake of Un-processed/Minimally Processed, and Ultra-processed foods at Home and Away from Home in the United States from 2003-2018

Background: Ultraprocessed foods (UPFs) comprise >50% of United States adults' energy intake, with the proportion of calories from UPFs increasing over time and the proportion of unprocessed/minimally processed foods (MPFs) decreasing over time. Whether UPFs are primarily consumed at home (AH) or away from home (AFH) is important to inform policies and messages to improve dietary quality.

Objectives: We examined trends in consumption of UPFs and MPFs AH and AFH in a nationally representative sample of United States adults and within sociodemographic subgroups.

Methods: Data are from 34,628 adults (aged ≥20 y) with two 24-h dietary recalls from the 2003-2018 National Health and Nutrition Examination Survey. We examined trends over time in intake from MPFs and UPFs as a proportion of total energy intake and as a proportion of AH energy intake and AFH energy intake using generalized linear models adjusted for sex, age, race/ethnicity, education, and household income. We examined differences in trends by sociodemographic subgroups using interaction terms and stratified models.

Results: Overall, and for most demographic subgroups, UPFs comprised >50% of AH energy intake and >50% of AFH energy intake, with UPFs increasing and MPFs decreasing over time as a proportion of energy intake AH and AFH. The proportion of total energy intake from UPFs increased for food consumed AH (33.6%-37.1%, P-trend < 0.001), but not for UPFs consumed AFH (19.5%-18.8%, P-trend = 0.88). From 2003-2004 to 2017-2018, the proportion of total energy intake from MPFs declined for foods consumed AH (23.6%-20.8%, P-trend <0.001) and AFH (9.7%-7.5%, P-trend <0.001). Interaction terms testing differences in trends of MPF and UPF intake AH and AFH by sociodemographic subgroups were mostly nonsignificant.

Conclusions: Findings highlight the ubiquity and increasing proportion of UPFs in United States adults' diets regardless of whether foods are consumed AH or AFH.