This Diet Change Cuts Over 300 Calories a Day, Without Decreasing Meal Size

ScienceAlert • February 17, 2026 • health

Key Points:

New research from the University of Bristol reveals that eating unprocessed wholefoods, like fruits and vegetables, allows people to consume larger portions yet take in fewer calories compared to ultra-processed foods (UPFs).
In a reanalysis of a 2019 clinical trial, participants ate over 50% more food on unprocessed diets but consumed 330 fewer calories daily than on UPF diets, suggesting natural foods help regulate calorie intake.
The study suggests humans possess a form of "nutritional intelligence," intuitively selecting foods that balance enjoyment, nutrition, and fullness when eating wholefoods, a mechanism disrupted by UPFs.
UPFs may cause calorie overload because they are energy-dense and fortified with micronutrients, underm