New study examines how obesity alters brain's reward circuits (2025)

Obesity is on the rise. Among U.S. adults aged 20 or older, 4 in 10 met the criteria for obesity in the most recent National Health and Nutrition Examination Survey, up from roughly 3 in 10 two decades earlier.

People with obesity have a significantly greater risk of developing Type 2 diabetes. Despite recent health advances, estimates suggest diet contributes to more than 300,000 deaths annually in the United States.

Decision-making surrounding food drives these health conditions. And decisions about what foods to eat is a leading, modifiable driver of disease burden."

AlexandraDiFeliceantonio, assistant professor at theFralin Biomedical Research Institute at VTCand interim co-director of its Center for Health Behaviors Research

DiFeliceantonio is part of a cross-disciplinary team that will explore how obesity affects brain circuits involved in reward, motivation, and emotions with support from a four-year, $2.75 million grant from the National Institute of Diabetes and Digestive and Kidney Diseases, part of the National Institutes of Health.

The goal is to bridge the translational gap between animal and human studies. It also will provide a foundation for testing the relationship between the brain's food-reward mechanisms and markers of metabolichealth and disease.

The other lead investigators areMatt Howe, assistant professor of neuroscience with Virginia Tech's College of Science, and ProfessorRead Montague, director of the Center for Human Neuroscience Research at the Fralin Biomedical Research Institute.

While animal studies in bees, rodents, and non-human primates have shown the role certain brain chemicals play in food and reward, scientists only recently have been able to track these chemicals in real time in people.

"Until the advances made by Dr. Montague, we had no way of measuring these signals at sub-second timescales for food reward tasks," DiFeliceantonio said. "It's important because there are findings that are foundational in neuroscience that might be different in human beings."

The Virginia Tech study will use groundbreaking electrochemistry techniquesdeveloped by Montague, a computational neuroscientist, and his team. The research, which involves neurochemical measurements taken using surgically implanted leads to monitor seizures in epilepsy patients, is being conducted in collaboration with Robert Bina, a neurosurgeon with the University of Arizona's Banner Health.

Scientists will measure brain chemical activity important for motivation and reward in people while they are drinking sugary drinks through a custom pump system and completing tasks related to emotion and food words to better understand how metabolic markers of health and disease influence decision-making.

"It's important to measure different types of rewards to understand if these brain chemicals encode something as basic as a sweet taste the same way as something complex like language," said Matt Howe, assistant professor of neuroscience in the College of Science.

"All the drugs used to treat overweight and obesity target these reward areas in the brain," DiFeliceantonio said. "Most of the evidence that we have is that even after weight loss, the brain doesn't just return to where it was before the weight gain." It's important to understand what's taking place as a foundation for next-generation interventions, she said.

DiFeliceantonio also holds an appointment in the Department of Human Nutrition, Foods, and Exercise in the College of Agriculture and Life Sciences. Montague also holds an appointment in the College of Science's Department of Physics.