Summary: New research suggests people’s food choices are guided by nutritional needs—micronutrients such as vitamins and minerals—rather than by calories alone.
Source: University of Bristol
New international research provides fresh evidence that human food preferences may be more deliberate than previously thought, with selections driven in part by a need for specific nutrients rather than solely by energy (calorie) content.
Led by the University of Bristol (UK), the study revisited the long-standing idea that humans evolved to favor energy-dense foods and that dietary balance emerges simply by sampling a variety of items. The researchers instead found patterns consistent with what is called “nutritional wisdom”—the tendency to prefer foods that help meet micronutrient requirements and to avoid combinations that could produce deficiencies.
Professor Jeff Brunstrom, lead author and Professor of Experimental Psychology, described the results as “hugely significant and rather surprising.” He said the findings mark the first time in nearly a century that robust evidence has been produced showing human food choice can reflect a selective drive for particular micronutrients rather than a generalized search for calories.
The paper, published in the journal Appetite, revisits themes from pioneering but controversial work in the 1930s by Dr Clara Davis, an American paediatrician who allowed a group of babies to “self-select” foods from a range of items. Although each child chose different combinations, they generally maintained good health, which was interpreted as early evidence of nutritional wisdom. Ethical constraints prevent direct replication of Davis’s experimental design with infants today, so this new research used alternative methods to test the idea in adults.
To avoid health or ethical risks, Brunstrom’s team developed a visual preference method. Participants were shown images of paired fruits and vegetables and asked to indicate which combinations they preferred. These images allowed researchers to infer selection biases without affecting participants’ diets.
A total of 128 adults took part across two experiments. The first study established that people consistently preferred some food pairings over others—for example, choosing apple with banana slightly more often than apple with blackberries. Importantly, statistical analysis showed that these preferences correlated with the micronutrient profiles of the pairings: combinations that offered a broader or more complementary range of vitamins and minerals were more likely to be chosen.
A second experiment used a different set of foods and ruled out alternative explanations for the observed choices, strengthening the case that micronutrient balance helps predict human selection of food combinations.
To validate the laboratory findings with real-world data, the researchers examined meal combinations reported in the UK’s National Diet and Nutrition Survey. Those data mirrored the experimental results: popular meal pairings—such as fish with chips or curry with rice—tended to provide a wider spectrum of micronutrients than randomly generated combinations, suggesting people naturally assemble meals that increase micronutrient exposure.
The study also came out of an unexpected collaboration. Co-author Mark Schatzker, a journalist and author affiliated as writer-in-residence at the Modern Diet and Physiology Research Center at Yale University, had previously argued in public talks and his book The Dorito Effect that humans often seek flavors and foods that are not necessarily calorie-rich. A debate at a scientific meeting prompted Brunstrom to test that idea experimentally; the resulting work indicates that humans may indeed be more discerning and nutrient-oriented than assumed.
Professor Brunstrom recalled approaching Schatzker after his talk and inviting him to test the hypothesis. The collaboration grew from that exchange and ultimately led to the experiments and analyses reported here. Schatzker notes the findings raise important questions about contemporary diets and the modern food environment—specifically whether processed foods and diet trends might interfere with or exploit this nutritional intelligence.
The researchers point out that animals use flavor cues to guide micronutrient intake, and if humans rely on similar signals, then highly flavored processed foods could mislead our preferences. By adding strong flavors to low-nutrient items such as potato crisps and sugary drinks, the food industry may be overriding or hijacking innate guides to micronutrient needs, with potential implications for overeating and obesity.
About this diet and nutrition research news
Author: Victoria Tagg
Source: University of Bristol
Contact: Victoria Tagg – University of Bristol
Image: The image is in the public domain
Original Research: The findings will appear in Appetite