A new study conducted by a 10-member team of scientists revealed what causes people to overeat. The research team included Sergio Iñiguez, Ph.D., associate professor of psychology at The University of Texas at El Paso. Iñiguez directed UTEP’s Iñiguez Behavioral Neuroscience Lab and helped formulate experimental techniques for the study Brandon Warren, Ph.D., assistant professor of pharmacodynamics at the University of Florida, led the study.
Their investigation discovered a specific area of the brain involved in recollection and the desire to seek food. This region of the brain triggers overconsumption of food in some people. The research could lead to inventions and treatments to prevent the desire to overeat.
Through the research, Iñiguez found that people tend to overeat when exposed to environments or triggers which encourage treats. This may explain why some people still desire dessert even after consuming a large meal. The study revealed that neurons in a certain brain region govern a person’s tendency to order dessert after seeing it. The team also found that rat subjects ate fewer treats when they regulated that area of the animal’s brain.
Diseases Associated with Overeating
- Type 2 diabetes
- high blood pressure
- high cholesterol
- coronary heart disease
“This is a big discovery because we now have experimental tools that allow us to turn off neurons while the subjects engage in a specific behavior,” Iñiguez said. “This research shows that a specific part of the prefrontal cortex of the brain is important for the initial stages of learning to seek food.”
Other studies on the link between the prefrontal cortex and overeating
The prefrontal cortex governs self-control, willpower, executive function, and the regulation of limbic reward regions. Studies have found that obese individuals have lower activation in the left dorsolateral PFC (DLPFC) area of the brain. This region of the brain regulates appetite and food cravings and helps with executive functioning. Therefore, researchers say that future treatments should target this brain region in people who overeat.
Another study led by Cassandra Lowe, a BrainsCAN postdoctoral fellow at the Western University in Ontario, Canada, found similar results. Lowe and colleagues wondered if people who tend to overeat had structural differences in their prefrontal cortex. They also wanted to know if obesity caused alterations in the structure and functioning of this area of the brain.
The study on what happens when you overeat
The researchers published their findings in the journal Trends in Cognitive Sciences.
Lowe and colleagues explained that previous studies on obesity have focused on the brain’s reward-processing mechanisms and areas. Specifically, the “striatum, midbrain, amygdala, and orbitofrontal cortex,” as well as the dopamine-releasing dorsal striatum, have been heavily studied. However, the authors say that the prefrontal cortex could also provide clues into the causes of overeating.
In addition to helping with executive functioning, this brain region helps with decision-making and planning future actions. It also acts as a “filter” to help a person respond appropriately in social situations.
Due to these repetitive behaviors surrounding food, the brain’s pathways become altered, creating a vicious cycle. Then, the new pathways in the brain encourage people to overeat at mealtimes. This ultimately leads to a mutually reinforcing relationship between overeating and the prefrontal cortex.
“It’s not just the case that obesity is causing these issues in the brain structure and function, but it is this reciprocal relationship — that differences in brain structure and function can cause obesity — that’s really important,” says Lowe.
Lowe also hopes that their research will lead to better treatments for obesity. “By reframing the issue of obesity around prefrontal activity, as opposed to reward region responsivity, we can explore treatments and preventative measures that may inhibit unwanted weight gain,” Lowe explains.
How mindfulness and exercise could help prevent overeating
Even though the brain responds strongly to habits and stimuli, we have the power to change them. Exercise and mindfulness, in particular, help increase activity in the prefrontal cortex and therefore regulate eating habits.
“Exercise has been shown to increase activity in our prefrontal cortex,” suggests Lowe, “which in turn lets us better ignore food cravings, going well beyond its traditional role as merely a means of getting rid of surplus calories.”
“By focusing on the healthiness and long-term consequences of the food we are eating instead of just taste, we are able to make better dietary choices,” she continues, explaining the benefits of mindfulness on eating habits.
What the co-author says
Study co-author Amy Reichelt, a BrainsCAN postdoctoral fellow at Western University, explains how childhood eating habits influence the brain.
“Making good eating habits during our formative childhood and adolescent years can help set healthy eating up for life and ensure the prefrontal cortex functions correctly,” Reichelt says.
“At this age, an adolescent’s prefrontal cortex is not fully developed, which in part explains the impulsive and hot-headed decision making of our youth — the control system isn’t fully engaged yet.”
“Related to this aptitude for poor decision making are poor eating habits,” she continues, “with adolescents eating more unnecessary calories from junk foods than any other age group, a habit that can last into adulthood.”
The researchers say that additional research is needed to solidify the benefits of exercise and mindfulness on obesity. They also hope to do further studies into how to personalize therapies and treatment modalities.
In a new study from top scientists, they found that the prefrontal cortex can cause someone to overeat. Specifically, when this area of the brain is underactive, it can cause disruptions in signals. This disrupts a person’s ability to make decisions, ward off food cravings, and eat moderately.
Other research shows that exercise and mindfulness can help stimulate the prefrontal cortex, which will improve functioning. However, they say more research is required to provide more evidence for this claim.
In summary, it’s reassuring to know that we have the power to overeat by altering our everyday habits.