What if your craving for a specific food was a reflection of a vitamin or mineral deficiency? For example, if you dream of tasting a banana, is this a sign that your body is lacking in magnesium? Could your craving for spinach or lentils be linked to a lack of iron?
In the 1930s, a scientist named Clara Davis looked into this amazing phenomenon, also known as “nutritional intelligence”. A group of young children who did not have access to healthy food at home were asked to choose freely from over thirty foods. Results? “Children instinctively chose a nutrient-dense diet”says the BBC.
Over time, however, the conclusions drawn by Clara Davis in her research work have been questioned by the scientific community. “We don’t really know what happened during this study”explains Jeff Brunstrom, professor of experimental psychology at the University of Bristol. “Maybe the kids were just exposed to a whole host of healthy foods and that was enough.”
Also, when Jeff Brunstrom crossed paths with journalist and author Mark Schatzker in 2017 during a conference on “the remarkable ability of different wild and domesticated species to respond to micronutrient deficiencies by modifying their diets accordingly”, his curiosity is piqued. Above all, the journalist believes that this phenomenon could also be observed in human beings. Despite his doubts, Brunstrom then proposed to Schatzker to test his theory during a scientific study.
“We showed participants pictures of fruits and vegetables in different combinations and then asked them to choose which combination they would opt for”describes Jeff Brunstrom. “To my amazement, the first study we did showed [que les participants choisissaient la meilleure option en termes de micronutriments]. It’s a small effect, but a reliable effect.”
That’s not all. In another study published April 30, 2022 in The American Journal of Clinical Nutrition and in which Brunstrom also participated, researchers used preexisting data from twenty people who had been asked to choose from a selection of daily meals with caloric intakes. different for four weeks. None of these people were dieting.
“For years we believed that humans were unconsciously consuming energy-dense meals”comments Annika Flynn, co-author of the study published on April 30, 2022. “Remarkably, this study indicates a degree of nutritional intelligence, by which humans manage to adjust the amount they consume when choosing energy-dense options.”
But if “nutritional intelligence” exists, how do you explain that people suffer from certain nutritional deficiencies that they could remedy? Similarly, why are some countries facing a rise in obesity if humans have “innate nutritional intelligence”? For the researchers, many questions remain unanswered for the moment, but they hope that their work will pave the way for further studies.
“The next set of questions should focus on the impact of this phenomenon on individual differences in health”argues Brunstrom. “We know that some people are more prone to poor dietary health and obesity than others. So what role does nutritional intelligence play, and can we understand how these interactions predispose us to over-consume or under-consume? It is also an exciting area.”