How young adults in the United States understand and conceptualise ultra-processed foods

Consumer understanding of ultra-processed foods (UPFs) is poor, and no consensus definition exists. This study examines how young adults in the United States (US) define UPF and their ability to differentiate UPF from non-UPF of varying nutritional quality (NQ). In a mixed-methods survey of young adults (18-39 years) living in the US for ≥1 year, respondents defined UPF, identified whether 24 foods were UPF or not using images with front and back of package information, and answered demographic questions. Foods were categorised using NOVA for processing and Food Compass for NQ. They included a high NQ non-UPF, low NQ non-UPF, high NQ UPF, and low NQ UPF item from six food groups: fruits, vegetables, dairy, grains, protein, and snacks/sweets. Concepts used to define UPF were reported as number of respondents mentioning each in their definition. A score of correct answers out of 24 was calculated. The sample of 422 adults, mean age 26.0±6.7 years, was predominantly white (82%), female (74%), and from the Northeast (82%). Thirty concepts were identified to define UPF. The top concepts were food containing additives, preservatives, colours/dyes, or natural or artificial flavours (N = 105), containing non-natural/artificial ingredients or food (N = 98), being highly processed/processed in multiple steps (N = 95), being altered, manipulated, or modified (N = 87), and having low nutritional value/nutrients removed (N = 75). The mean score was 16.0±3.6 (67%) foods. These results suggest limited consensus on how young adults define UPF. Studies in more diverse populations are needed, but consumers may benefit from a clear definition of UPF.