Tiny Tummies, Big Questions: Unpacking Ultra-Processed Ingredients and Additives in Complementary Foods in the United States

Background/Objectives: Ultra-processed foods (UPFs) consumption is increasing among infants and young children below three years of age, but to what extent is unclear. Understanding ingredient profiles in commercially produced complementary foods is critical given emerging evidence linking UPF consumption in early life with adverse health trajectories. The objective of this study was to assess the degree of processing and characterize the types of ingredients and additives used in commercial complementary foods available in major US grocery stores. Methods: This was a cross-sectional analysis of 651 infant and toddler food products sold by the top 10 largest US grocery stores in 2023. Data were collected from 8 of the 10 stores in Raleigh, North Carolina, and from 2 of the 10 stores online. Ingredients were classified into types and subtypes using Codex Alimentarius and US FDA taxonomies. UPFs were identified using the Nova classification system. The number of UPF ingredients per product and the proportion of products that were considered UPFs were calculated. Mean nutrient levels were compared between UPFs and non-UPFs. Results were examined by category and packaging type. Results: 71% of products were classified as UPFs. In addition, additives were present in 71% of products, with flavor enhancers (36%), thickeners (29%), emulsifiers (19%), and colors (19%) being the most common UPF-marker additives used. Ingredient counts varied widely (range 1–56), with snacks containing the most ingredients. Processed fruit and vegetable ingredients were common, while dairy, meat, and legume ingredients were uncommon. UPF products contained higher mean levels of total sugar, added sugar, sodium, and energy density than non-UPF products. Added sugars were present exclusively in UPF products. Conclusions: Most US commercial complementary foods are ultra-processed and contain multiple additives. These findings highlight the need for improved labeling and regulatory standards for identifying UPF ingredients and additives to ensure the availability of appropriate and healthy products targeting the youngest consumers.