The brain may become more sensitive to food cues as children consume more ultra-processed foods.
A brain accustomed to consuming ultra-processed foods could be more sensitive to the reward effect induced by appetizing foods: research from the Keck School of Medicine at the University of Southern California reveals a possible neurobiological mechanism underlying the link between a diet rich in ultra-processed foods and weight gain.
Children who find themselves with a greater quantity of ultra-processed foods on their plates have brains that respond more intensely to images of delicious and tasty foods, and the intensity of these responses is linked to subsequent weight gain. The results were published in the scientific journal JAMA Network Open.
The wrong stimulus in the learning age
In the United States, where the study was conducted, children get an average of 67% of their daily calories from ultra-processed foods, foods that are deeply transformed during industrial processing and designed to be palatable, economical, long-lasting and easy to consume. These foods often include colorings, additives, preservatives or processing methods that cannot be found or replicated at home and have been linked by numerous studies to health problems – such as childhood obesity, type 2 diabetes, cardiovascular problems.
Easier activation
The new study involved 46 children aged between 7 and 10 years participating in a long-term study on the risks of diabetes and obesity. At the beginning of the analysis, the children had normal body weight, which allowed the researchers to study the effect of the ultraprocesses more precisely.
The researchers performed MRI scans of the children’s brains while they viewed images of appetizing foods (for example, cookies or chips). The scientists also collected data on their diet, body mass index, body fat percentage and waist size. And they repeated the measurements a year later.
Those who consumed more ultra-processed foods also showed stronger responses to food photos in the dorsal striatum brain region, involved in reward and motivation. Not only that: more intense responses in this region were associated with an increase in body mass index – i.e. the ratio between weight (kg) and the square of height (square metres) – and in the percentage of fat after one year.
Improve food supply
According to the authors of the study, the different brain responses to ultraprocessed foods could explain the link between these foods and weight gain: a brain more receptive to the reward effect induced by these foods could lead to greater consumption of this type of food.
But what changes, the scientists point out, is not just the purchasing habits of families and the food preferences of children: it is the food supply that must be modified, because ultra-processed foods are often also more economically accessible and practical to consume.
