While numerous studies have highlighted that ultra-processed foods are not good for our health, a recent groundbreaking study from Germany indicates that highly processed foods can alter our brain function.
The study, conducted by researchers at the University Hospital of Tubingen, the German Center for Diabetes Research, and Helmholtz Munich, demonstrated that even short-term consumption of ultra-processed foods can significantly change the brain’s response to insulin. This altered response, in turn, could lead to obesity and Type 2 diabetes.
The study focused on how consuming extra calories affects insulin response in the brain. Insulin, a hormone produced by the pancreas, helps regulate appetite and metabolism. However, when insulin resistance develops in the brain, this can disrupt the energy balance and change a person’s eating behaviors.
Researchers recruited 29 healthy-weight men between the ages of 19 and 27 for the study. The participants were divided into two groups: the control group consumed their usual diet, while the test group consumed an extra 1,500 calories per day for five days in the form of highly processed snack foods, like chips and candy bars.
The participants underwent magnetic resonance imaging to measure their brain insulin response before the five-day period, immediately after, and again one week later, after resuming their normal eating habits. Changes in body composition, liver fat, and insulin sensitivity in the rest of the body were also assessed.
The test results showed that brain activity increased in areas associated with reward processing for those who consumed the extra calories, similar to what is seen in the brain scans of people with obesity. Even one week after resuming a normal diet, insulin sensitivity in the area of the brain involved in memory remained altered, suggesting that food intake can have long-term effects on the brain. Fat levels in the liver also increased significantly, even though the participants gained no weight.
“Our findings demonstrate for the first time that even a brief consumption of highly processed, unhealthy foods causes a significant alteration in the brain of healthy individuals, which may be the initial cause of obesity and type 2 diabetes,” said Prof. Stephanie Kullmann, the study leader.
“Interestingly, in our healthy study participants, the brain shows a similar decrease in sensitivity to insulin after short-term high-calorie intake as in people with obesity.”
“We assume that the brain’s insulin response adapts to short-term changes in diet before any weight gain occurs and thus promotes the development of obesity and other secondary diseases,” Dr. Andreas Birkenfeld, the study’s author, concluded.
However, he noted that more research is needed to discover how the brain contributes to the development of obesity and other metabolic illnesses.