Virginia Tech researchers study how obesity changes brain responses to food.
Obesity has grown steadily more common in recent decades. In the United States, around 40% of adults aged 20 or older now meet the criteria for obesity, a sharp rise from approximately 30% two decades earlier. This trend has sparked concern within the medical and research communities due to strong links between obesity and serious health conditions such as Type 2 diabetes. Despite progress in treatment and prevention, diet remains connected to over 300,000 deaths each year across the country, and scientists believe the way obesity changes brain function is to blame.
Food choice plays a major role in this issue. Decisions about what to eat are not simply about nutrition or habit but are deeply influenced by how the brain reacts to certain foods. A team of researchers from Virginia Tech is working to better understand how obesity affects specific brain circuits tied to pleasure, motivation, and emotional response to food. With funding from the National Institute of Diabetes and Digestive and Kidney Diseases, the team is using new tools to study brain chemistry in real time.
Past studies in animals have shown that certain brain chemicals drive responses to food and reward. These chemicals are now being tracked in humans using advanced electrochemical technology. Until recently, this level of detail was not possible in human research. Now, using methods developed by a team led by computational neuroscientist Read Montague, scientists can monitor these signals down to the millisecond. The technology involves surgically implanted devices originally used to monitor seizures in epilepsy patients. While these patients are being observed, researchers can study their brain activity during tasks involving food and emotional processing.
During the study, participants are given sugary drinks through a special system while engaging in simple tasks involving food-related words and emotional cues. These sessions help researchers measure how the brain responds to different kinds of rewards, from sweet tastes to language. This approach makes it possible to observe the relationship between brain chemistry and markers of metabolic health, including those linked to obesity and diabetes.
Other researchers involved include neuroscience professor Matt Howe and assistant professor Alexandra DiFeliceantonio. The study builds on previous work showing that treatments for obesity often target the brain’s reward system. Many of these drugs are based on findings from animal research, but human responses can differ in important ways. According to the team, understanding these differences could lead to better therapies in the future.
One key finding is that even after weight loss, the brain’s reward circuits may not return to their earlier state. The way obesity changes brain function could have lasting effects that influence how the brain continues to respond to food. This may help explain why maintaining weight loss is difficult, even after successful dieting or medical treatment. The current research is designed to give a clearer picture of these long-term changes.
By comparing how the brain processes simple pleasures like sweetness versus more complex experiences like reading food-related words, researchers hope to learn how deeply these systems are affected. Insights into how obesity changes brain function could help in creating new treatments that go beyond diet and exercise alone. A better understanding of brain responses may lead to approaches that support long-term health in people living with obesity.
Sources:
Obesity and Severe Obesity Prevalence in Adults: United States, August 2021–August 2023
New study examines how obesity alters brain’s reward
What overrides the brain’s satiety signals and prompts overeating
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