Summary: Obesity risk in teens appears to be associated with stronger connectivity within and between regions of the brain implicated in determining the salience of stimuli. This may have implications for reward processing. Researchers report executive control efforts in the brain decrease when salience and reward-processing regions are engaged in teens with obesity.
Source: University of Michigan
In teens with obesity problems, the brain regions that process rewards are strongly connected, or more likely to “talk” to each other.
These regions, however, are less connected to those involved in memory and executive functioning—such as decision-making, attention and behavioral control—that could make teens more sensitive to rewards like junk foods, according to a new University of Michigan study.
Researchers say teens with obesity have a hard time inhibiting behavior regarding those rewards.
The findings, published in the journal Obesity, are the latest effort to help lower obesity rates among teens. This public health threat of overconsumption of unhealthy foods has been a crisis worldwide, and it has worsened during the pandemic.
More than 160 teens (ages 13 to 16)—whose weight ranged from lean to obesity—had their brains scanned. They also rated their hunger levels. Researchers wanted to analyze various brain regions:
Default mode network, which controls mental imagery and mind wandering.
Executive function network, which is important for attention, controlling inhibitions and memory.
Salience network, which processes information related to emotion and reward.
Obesity appears to be related to stronger connectivity within and between regions implicated in determining the salience of stimuli, which may have implications for reward processing. Lower connectivity between salience network and executive function network regions may suggest that executive-control efforts are going “off-line” when salience and reward-processing regions are engaged in adolescents who have obesity.
“Understanding weight-related differences in network connectivity can guide prevention and intervention efforts, and the current findings highlight the importance of targeting response to salient and rewarding food-related stimuli,” said study lead author Michelle Borowitz, who received her doctorate in psychology from U-M in 2019.
Other co-authors include: Sonja Yokum, a researcher at the Oregon Research Institute; Elizabeth Duval, U-M assistant professor of psychiatry; and Ashley Gearhardt, U-M associate professor of psychology.
About this depression research article
Source: University of Michigan Media Contacts: Jared Wadley – University of Michigan Image Source: The image is in the public domain.
Weight‐Related Differences in Salience, Default Mode, and Executive Function Network Connectivity in Adolescents
Objective The current study examined whether adolescents with weight status ranging from lean to obesity showed weight‐related differences in the default mode network (DMN), the executive function network (EFN), and the salience network (SN).
Methods One hundred sixty‐four adolescents participated in a resting‐state functional connectivity scan. A general linear model was used to examine differences in scan patterns among adolescents with lean weight, overweight, and obesity.
Results Adolescents with obesity compared with those with lean weight showed stronger within‐SN connectivity among the medial orbitofrontal cortex, olfactory tubercle, and pallidum; however, they showed lower connectivity between the amygdala and SN regions (nucleus accumbens, thalamus, putamen). Those with obesity also showed lower connectivity between SN (amygdala, caudate) and DMN (parahippocampus, hippocampus, precuneus) regions. Adolescents with obesity compared with those with lean weight showed lower connectivity between SN (medial orbitofrontal cortex) and EFN (ventrolateral prefrontal cortex) regions.
Conclusions Obesity appears to be related to stronger connectivity within and between regions implicated in determining the salience of stimuli, which may have implications for reward processing. Lower connectivity between SN and EFN regions may suggest that executive‐control efforts are going “off‐line” when salience and reward‐processing regions are engaged in adolescents who have obesity.