For anyone embarking on a New Year's resolution to lose weight, the challenge of feeling full while managing calories is a familiar struggle. However, a pivotal new study offers a compelling solution, revealing that the type of food you eat can naturally guide you towards healthier choices and a lower calorie intake.
The Power of Unprocessed Eating
Research published in The American Journal of Clinical Nutrition on Tuesday 20 January 2026 provides striking evidence. Scientists found that participants who followed an unprocessed diet instinctively chose to eat significantly more fruits and vegetables over higher-calorie wholefoods like rice, meat, and butter.
The data is clear: people on the unprocessed diet could eat over 50 per cent more food by mass, yet they consumed an average of 330 fewer calories per day compared to those on an ultra-processed diet. This suggests that volume of food eaten is not the primary driver of weight gain; the nutritional quality is.
Unlocking Our Body's 'Nutritional Intelligence'
The study's author, Professor Jeff Brunstrom, explained to The Independent that the findings challenge the long-held belief that humans are simply drawn to high-calorie foods. Instead, he argues we possess a form of 'nutritional intelligence' that also seeks out vital micronutrients.
"We don't just eat for calories, and this paper argues that micronutrients play a role as well," stated Prof Brunstrom. He described how, on a wholesome diet, our body serves two systems: one for calories and another that draws us towards foods rich in essential vitamins and minerals.
The research was a reanalysis of a landmark 2019 study which first highlighted the link between ultra-processed foods, excessive calorie intake, and weight gain. This new examination found that when eating exclusively wholefoods, people consistently preferred micronutrient-rich produce like spinach and carrots, which provided vitamin A, over processed sources like French toast sticks.
The Crucial 'Tension' That Puts a Brake on Calories
Professor Brunstrom introduced a key concept: in a natural, unprocessed diet, a 'tension' exists between macronutrients and calories. This tension acts as a natural brake, limiting our overall calorie consumption even when we eat a larger volume of food.
"Overeating is not necessarily the core problem," he emphasised. "Indeed, our research clearly demonstrated consumers on a wholefood diet actually ate far more than those on a processed food one. But the nutritional make-up of food is influencing choices."
The study concludes that ultra-processed foods (UPFs) effectively nudge people towards higher-calorie options. Even in smaller quantities, these options lead to excess energy intake, which in turn fuels the obesity epidemic. The findings underscore that shifting towards an unprocessed diet can harness the body's innate wisdom to support healthier weight management.
