845
Researchers from the University Hospital of Tübingen have found that the brain plays a crucial role in the development of obesity through changes in insulin sensitivity that occur even after short-term consumption of highly processed foods.
The global problem of obesity
Obesity has become a global epidemic, affecting over a billion people worldwide, including nearly 16 million in Germany. Only in 2020 was obesity officially recognized as a disease in Germany.
Traditionally, the main causes of obesity are believed to be poor diet and lack of physical activity. However, German researchers have found that the biological mechanisms behind the development of this condition are much more complex.
The World Health Organization classifies obesity as a condition with a body mass index of 30 or higher. It is associated with an increased risk of diabetes, heart disease, and cancer.
Insulin and the brain: a new perspective
Professor Stephanie Kuhlmann and her team investigated how insulin affects the brain and its relationship to fat distribution in the body. "Our results demonstrate for the first time that even short-term consumption of highly processed, unhealthy foods causes significant changes in the brains of healthy people", – notes Professor Kuhlmann.
In a healthy state, insulin acts on the brain to suppress appetite. However, in obesity, this mechanism is disrupted, leading to insulin resistance.
An unexpected finding was that the brains of healthy study participants showed the same decrease in insulin sensitivity after short-term consumption of high-calorie food as those of obese people.
Research methodology and results
The study involved 29 average-weight male volunteers, divided into two groups. The first group added 1500 calories of highly processed snacks to their regular diet for five days.
The researchers used magnetic resonance imaging to assess liver fat content and brain insulin sensitivity. The scans were performed immediately after the five-day period and one week after returning to a normal diet.
The results showed that the fat content in the liver of the first group increased significantly after five days of increased calorie intake. The most striking discovery was that the reduced brain sensitivity to insulin persisted a week after returning to a normal diet..
Prospects for future research
Professor Andreas Birkenfeld, one of the lead authors of the study, concludes: "We hypothesize that the brain's insulin response adapts to short-term changes in diet before weight gain occurs.".
He calls for further research into the role of the brain in the development of obesity and other metabolic diseases. These findings could have a significant impact on the development of new approaches to obesity prevention and treatment.
New understanding of the mechanisms of obesity development emphasizes the importance not only of controlling caloric intake, but also of considering the impact of food quality on brain insulin sensitivity.
