A groundbreaking new study suggests the secret to consuming fewer calories may not be eating less, but rather changing what you eat. Researchers have found that people who avoid ultra-processed foods (UPFs) eat significantly more food by weight, yet still consume far fewer calories overall.
The Wholefoods Advantage: More Food, Fewer Calories
Experts from the University of Bristol reanalysed data from a US clinical trial involving 20 participants. Their findings, published in the American Journal of Clinical Nutrition, are striking. Individuals eating solely wholefoods consumed 57% more food when measured by weight, yet their overall calorie intake was an average of 330 calories lower per day compared to those on a diet of ultra-processed foods.
Professor Jeff Brunstrom, Professor of Experimental Psychology at the University of Bristol, explained the intuitive choices people made. "It's exciting to see when people are offered unprocessed options they intuitively select foods that balance enjoyment, nutrition, and a sense of fullness, while still reducing overall energy intake," he said. "Our dietary choices aren't random – in fact we seem to make much smarter decisions than previously assumed, when foods are presented in their natural state."
Why Ultra-Processed Foods Disrupt Our Choices
The study indicates that the nutritional makeup of UPFs subtly guides people towards higher-calorie options. Even in smaller quantities, these foods can lead to excess energy intake, fuelling weight gain. "Overeating is not necessarily the core problem," stated Prof Brunstrom. "Indeed, our research clearly demonstrated consumers on a wholefood diet actually ate far more than those on a processed food one."
A critical issue highlighted by the research is the fortification of UPFs. While items like pancakes and French toast sticks were found to contain added vitamin A, people on the wholefood diet obtained the same nutrient from low-calorie sources like carrots and spinach.
Dr Annika Flynn, Senior Research Associate at the University of Bristol, warned of the implications. "This raises the alarming possibility that UPFs deliver both high energy and micronutrients in one hit, which could result in calorie overload," she said. "They effectively kill the beneficial trade-off between calories and micronutrients."
The Natural Path to Better Nutrition
In contrast, a diet based on wholefoods promotes what Dr Flynn calls a "healthy competition." This encourages people to favour "micronutrient powerhouses," such as fruits and vegetables, over energy-dense options like pasta and cream. The research ultimately suggests that the problem lies more in the type of food consumed rather than simple portion control.
By presenting food in its natural state, individuals appear naturally inclined to make choices that support fullness, nutrition, and a lower calorie count, offering a fresh perspective on tackling obesity and improving public health.
