Does the need for specific nutrients drive our food choices?

According to a new study, humans have in-built wisdom, selecting foods containing specific nutrients that benefit health.

Whilst other animals have innate intelligence when selecting the right foods to meet their nutritional needs, very little is known about what drives human food choices.

Scientists widely believe that human dietary choices evolved to prioritise high energy foods and the micronutrients in our diets occur by chance from eating a wide range of foods.

In two experiments, the notion was tested by Professor Jeffery Brunstrom from Bristol University, UK and Mark Schatzker, journalist and writer in residence at Yale University.

Researchers showed 128 adults images of paired fruit and vegetables in the first experiment and recorded their preferences. The preferred food pairs contained the most varied balance of nutrients overall. For example, people chose images of apples and bananas more frequently than images of apples and blackberries.

The second study analysed data from a large-scale nutritional survey in the UK and found similar results; common food choices were those providing the most balanced nutrient intake. For example, fish and chips or curry and rice offered a broader range of nutrients than randomly chosen meals.

The results support research carried out in the 1930s by American paediatrician Dr Clara Davis. When babies were allowed to choose their diet from 33 different foods, they all ate foods that maintained good health despite choosing different combinations. However, modern ethics meant replication of the study was not permitted. So nearly 100 years have passed since science has explored whether humans have the same innate intelligence.

Jeff Brunstrom said in a Bristol University press release: “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 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?” commented Mark Schatzker in the press release.

“Studies have shown animals use flavour as a guide to the vitamins and minerals they require. If flavour 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 flavourings 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, said Mark.”

The study is published in the journal Nutrients.

Reference: Brunstrom,J.M & Schatzker. M. (2022). Micronutrients and food choice: A case of ‘nutritional wisdom’ in humans? Appetite, 174, 106055: DOI: 10.1016/j.appet.2022.106055

Press release source: https://www.bristol.ac.uk/news/2022/april/nutritional-intelligence-media-release.html