Cell Metab. 30, 1–11 (2019)

Consumption of processed food results in consumers eating more calories than if they are presented with only unprocessed food.

Ultra-processed foods are thought to contribute to adverse health outcomes, including obesity; however, this has not yet been proven.

A group of researchers in the United States recruited 20 inpatient adults to a diet study. They were fed a processed diet for 2 weeks and then an unprocessed diet for 2 weeks, or vice versa. The amounts of calories, sugar, fat, fiber and macronutrients were matched between the diets, but the individuals were able to eat ad libitum. Consuming the diet of unprocessed food resulted in elevated calorie intake, weight gain and associated adverse health outcomes.