Study Links Ultra-processed Foods to Increased Calorie Intake in Young Adults
BLACKSBURG, VA - February 26, 2025 – A new study from Virginia Tech adn Johns Hopkins University suggests that diets high in ultra-processed foods may lead to increased calorie consumption, particularly in young adults aged 18 to 21. The findings, published Wednesday in the journal Obesity, indicate that individuals who recently consumed a diet comprised of 81% ultra-processed foods ate substantially more calories and snacked more frequently, even when not hungry, compared to those who followed a diet with no ultra-processed foods.
Researchers carefully matched both diets – one high in ultra-processed foods and one without – on 22 characteristics, including macronutrients, fiber, added sugar, energy density, vitamins, and minerals. ”We very rigorously designed these diets to be matched on 22 characteristics… Previous studies had not matched diets to this extent,” explained study senior author Brenda Davy, professor of human nutrition, foods and exercise at Virginia Tech.
The study involved 27 young people who followed the specialized diets for two weeks, after which their eating habits were tracked for a month during “normal” eating conditions. While the overall group showed no important change in calorie intake or preference for ultra-processed foods after the diets, a clear pattern emerged within the younger age group.
Those aged 18 to 21 who had been on the ultra-processed food diet consumed more calories at an “all you can eat” breakfast buffet and exhibited increased snacking behavior. “Given the opportunity to snack when not hungry, they ate more yet again,” said DiFeliceantonio, an assistant professor in the Department of Human nutrition, Foods, and Exercise. No such changes were observed in the 18-to-21-year-olds who followed the diet emphasizing unprocessed or minimally processed foods.
Researchers caution that this increase in caloric intake, if sustained over time, could contribute to weight gain in young adults. “Although this was short-term trial, if this increase in caloric intake persists over time, this could lead to weight gain in these young people,” Davy stated.
The team emphasizes the need for further research, particularly with larger groups of younger teens and in more realistic settings. They also suggest investigating the biological mechanisms – involving brain activity and biomarkers – that may explain how certain foods trigger overeating.
