Research paper
Hall KD, Ayuketah A, Brychta R, Cai H, Cassimatis T, Chen KY, Chung ST, Costa E, Courville A, Darcey V, Fletcher LA, Forde CG, Gharib AM, Guo J, Howard R, Joseph PV, McGehee S, Ouwerkerk R, Raisinger K, Rozga I, Stagliano M, Walter M, Walter PJ, Yang S, Zhou M. Ultra-processed diets cause excess calorie intake and weight gain: an inpatient randomized controlled trial of ad libitum food intake. Cell Metabolism. 2019;30(1):67-77.e3. doi:10.1016/j.cmet.2019.05.008
Why we cite it
Provides a randomized crossover trial demonstrating that ultra-processed diets cause excess calorie intake and weight gain — showing that 20 inpatient adults ate 508 kcal/day more on ultra-processed vs. unprocessed diets matched for presented calories, macronutrients, sugar, fat, fiber, and sodium, a design that supports a causal reading. The authors write that no causal relationship between ultra-processed food consumption and human obesity ”has yet been established”, and that ”there has never been a randomized controlled trial demonstrating any beneficial effects of reducing ultra-processed foods” — their claim about the prior literature, not one this library has checked (corrected 2026-09-10 from ”establishing causality where previously only observational associations existed”: observational does not occur in the paper).