The new study asserts that people have an inbuilt ability to choose a diet that is optimal for health – called ‘nutritional wisdom’. But the food industry is apparently messing with our innate food choices.
Humans possess ‘surprising’ nutritional intelligence, claims the research. We don’t just eat for calories but possess nutritional wisdom that means we instinctively seek a variety vitamins and minerals and avoid nutritional deficiencies.
The international study, led by the University of Bristol in the UK, published in the journal Appetite, gives renewed weight to the infamous research carried out in the 1930s by an American paediatrician Dr Clara Davis. Here, a group of 15 babies were allowed to “self-select”, in other words eat whatever they wanted, from 33 different food items. While no child ate the same combination of foods, they all achieved and maintained a good state of health, which was taken as evidence of “nutritional wisdom”.
Its findings were later scrutinised and criticised. However, replicating the research was not possible because this form of experimentation on babies would today be considered unethical. As a result, it has been nearly a century since any scientist has attempted to find evidence for nutritional wisdom in humans – a faculty which has also been found in other animals, such as sheep and rodents.
To overcome these barriers, University of Bristol Professor of Experimental Psychology Jeff Brunstrom and team developed a novel technique which involved measuring preference by showing people images of different fruit and vegetable pairings so their choices could be analysed 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. For example, apple and banana might be chosen slightly more often than apple and blackberries. Remarkably, these preferences appear to be predicted by the amounts of micronutrients in a pair and whether their combination provides a balance of different micronutrients. To confirm this, they 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. Specifically, components of popular UK meals, for example ‘fish and chips’ or ‘curry and rice’, seem to offer a wider range of micronutrients than meal combinations generated randomly, such as ‘chips and curry’.
“The results of our studies are hugely significant and rather surprising,” said Professor Brunstrom. “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… humans seem to possess a discerning intelligence when it comes to selecting a nutritious diet.”
The study has interesting implications for the food industry such as the benefits – real or not – of of ‘natural eating’ and the likes of paleo and gluten-free diets.
“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?” said Mark Schatzker, a journalist and author and the study co-author, who is also the writer-in-residence at the Modern Diet and Physiology Research Center, affiliated with Yale University.
He further used the research to accuse the food industry of distorting with our inborn food choices.
“Studies have shown animals use flavour as a guide to the vitamins and minerals they require,” he explained. “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.”
Are bliss points overriding natural 'stop' signals?
Dr Bunmi Aboaba, who helps clients overcome food addiction, has also blamed the industry for creating ‘bliss points’ in food formulation to optimize deliciousness.
She said this combination of fats, sugars, carbohydrates and salts provides an intense dopamine surge. “What happens when the brain mirrors and your reward system of the brain is overly excited by the huge surge of dopamine?” she asked. “The pre-frontal cortex, the CEO - or thinking part - of the brain, finds it difficult to make rational decisions. Hence the choices made are heavily weighted towards the food that ‘ignite’ the pleasure /reward pathways.”
Once a person is addicted to certain “trigger foods”, argued Aboaba, those foods change the brain in ways that make abstaining from them very challenging — even for those who desperately want to stop and with all the determination they can muster.
“There is a continuing misconception that people have absolute control over what they eat and drink. To put it another way, bad diets are simply the result of bad individual choices. This simply is not true. Instead, people tend to eat what they are exposed to, what is readily available, and what is accessible physically and economically.”
Micronutrients and food choice: A case of ‘nutritional wisdom’ in humans?