BRISTOL, UK, April 26, 2022 (ENS) – Pioneering research by a British-led team has shed new light on what drives people’s basic food preferences. It shows that our choices may be smarter than previously understood – that we make choices driven by the need for specific nutrients, rather than by the need for calories alone.
Led by the University of Bristol, the international scientific team set out to re-examine and test the widely-held view that humans evolved to favor energy-dense foods and our diets are balanced by eating a variety of different foods. Contrary to this belief, the team found that people seem to have “nutritional wisdom,” whereby foods are selected in part to meet our need for vitamins and minerals and avoid nutritional deficiencies.
Lead author Jeff Brunstrom, professor of experimental psychology, said, “The results of our studies are hugely significant and rather surprising. For the first time in almost a century, we’ve shown humans are more sophisticated in their food choices, and appear to select based on specific micronutrients rather than simply eating everything and getting what they need by default.”
The paper, published April 25 in the journal “Appetite,” gives renewed weight to research carried out back in the 1930s by American pediatrician Dr. Clara Davis, who put a group of 15 babies on a diet which allowed them to eat whatever they wanted from 33 different food items. While no baby ate the same combination of foods as any other of the subject babies, they all achieved and maintained a good state of health. That fact was taken as evidence of “nutritional wisdom.”
Dr. Davis’s findings were later criticized, but replicating her research was not possible because this form of experimentation on babies would today be considered unethical. So, it has been nearly a century since any scientist has attempted to find evidence for nutritional wisdom in humans, a characteristic that has been found in other animals, such as sheep and rodents.
To overcome these barriers, Professor Brunstrom’s team developed a technique that measured preferences by showing people images of different fruit and vegetable pairings so their choices could be analyzed without putting their health or wellbeing at risk.
In total,128 adults participated in two experiments. The first study showed people prefer certain food combinations more than others. Apple and banana might be chosen slightly more often than apple and blackberries, for instance.
The researchers found it remarkable that these preferences appeared to be predicted by the amounts of micronutrients in a pair of foods and whether or not their combination provides a balance of different micronutrients.
To confirm this, the researchers ran a second experiment with different foods and ruled out other explanations.
To complement and cross-check these findings, real-world meal combinations as reported in the UK’s National Diet and Nutrition Survey were studied. Similarly, these data demonstrated people combine meals in a way that increases exposure to micronutrients in their diet.
Professor Brunstrom’s co-author is Mark Schatzker, a journalist and author, and also the writer-in-residence at the Modern Diet and Physiology Research Center, affiliated with Yale University.
In 2018, the two met in Florida at the annual meeting of the Society for the Study of Ingestive Behavior, where Schatzker delivered a talk about his book, “The Dorito Effect,” which examines how the flavor of whole foods and processed foods has changed, and the implications for human health and wellness.
Schatzker commented on his colleague’s findings, saying, “The research throws up important questions, especially in the modern food environment. For example, does our cultural fixation with fad diets, which limit or forbid consumption of certain types of foods, disrupt or disturb this dietary “intelligence” in ways we do not understand?”
“Studies have shown animals use flavor as a guide to the vitamins and minerals they require,” Schatzker said. “If flavor serves a similar role for humans, then we may be imbuing junk foods such as potato chips and fizzy drinks with a false ‘sheen’ of nutrition by adding flavorings to them. In other words, the food industry may be turning our nutritional wisdom against us, making us eat food we would normally avoid and thus contributing to the obesity epidemic.”
Featured image: Many fruits at La Boqueria Market in Barcelona, one of Europe’s largest and most famous food markets. The oldest record of a market in this place is from 1217. Barcelona, Spain, September 21, 2011 (Photo by Mike McBey)