Lewis Wallis is a Senior Nutrition Scientist at the British Nutrition Foundation, with a focus on using data and insights to support food system transformation. He has extensive experience in interpreting and implementing food legislation and nutrition policy, with particular expertise in HFSS restrictions, nutrient profiling, ultra-processed food (UPF) definitions and their application to product-level data.
Alongside his role, Lewis is a postgraduate researcher at the University of Leeds investigating digital food retail environments and how digital features may influence healthier and more sustainable food choices.
Ideas developed from the author’s original article From Broad Concepts to Operational Definitions The debate around “ultra-processed foods” (“UPFs”) is entering a new phase. At the end of 2025, The Lancet published a 3-paper series on “UPFs”, covering health associations and policy recommendations1. Much of the evidence underpinning this classification comes from observational studies that…
