Tag Archives: teenage

Is childhood obesity a psychological disorder?

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A team of researchers, including senior investigator, Bradley Peterson, MD, director of the Institute for the Developing Mind at Children’s Hospital Los Angeles, used fMRI to investigate neural responses to food cues in overweight compared with lean adolescents. The team observed that food stimuli activated regions of the brain associated with reward and emotion in all groups. However, adolescents at an increasing risk for obesity had progressively less neural activity in circuits of the brain that support self-regulation and attention.

“This study establishes that risk for obesity isn’t driven exclusively by the absence or presence of urges to eat high-calorie foods, but also, and perhaps most importantly, by the ability to control those urges,” said Peterson, who is also a professor at the Keck School of Medicine at the University of Southern California.

The public health implications of childhood obesity are staggering. More than half of all adolescents in the U.S. are either overweight or obese. Children of overweight parents (2/3 of adults in the U.S.) already are or are likely to become overweight. Since excess weight has been linked to a myriad of health issues shown to limit human potential and add to the skyrocketing cost of healthcare, researchers are actively seeking novel approaches to understand better the causes of obesity and alter its trajectory. This study, recently reported in the journal NeuroImage, may offer such an approach.

“We wanted to use brain imaging to investigate a key question in obesity science: why do some people become obese, while others don’t?” said Susan Carnell, PhD, assistant professor of Child & Adolescent Psychiatry, Johns Hopkins University School of Medicine and first author on the study.

Of the 36 adolescents (ages 14 to 19 years) enrolled in the study, 10 were overweight/obese, 16 were lean but considered at high risk for obesity because they had overweight/obese mothers and 10 were lean/low risk since they had lean mothers. The adolescents underwent brain scanning using fMRI, while they viewed words that described high-fat foods, low-fat foods and non-food items. Then they rated their appetite in response to each word stimulus. Following the activity, all participants were offered a buffet that included low- and high-calorie foods — to relate participants test responses to real-world behavior.

The investigators observed that after viewing food-related words, brain circuits that support reward and emotion were stimulated in all participants. In adolescents who were obese or who were lean but at high familial risk for obesity, they observed less activation in attention and self-regulation circuits.

Brain circuits that support attention and self-regulation showed the greatest activation in lean/low-risk adolescents, less activity in lean/high-risk participants and least activation in the overweight/obese group. Also, real world relevance mirrored fMRI findings — food intake at the buffet was greatest in the overweight/obese participants, followed by the lean/high-risk adolescents and lowest in the lean/low-risk group.

“These findings suggest that interventions designed to stimulate the self-regulatory system in adolescents may provide a new approach for treating and preventing obesity,” said Peterson.

Smartphone tracking shows fear affects where youth spend time

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Youth spend less time in their neighborhoods if area residents have a high fear of crime, according to a new study that used smartphones to track kids’ whereabouts.

Researchers found that adolescents aged 11 to 17 spent over an hour less each day on average in their neighborhoods if residents there were very fearful, compared to kids from areas perceived as being safer. Higher fear of crime was linked to high-poverty neighborhoods.

This is the first study to use smartphone data to track a large, diverse sample of young people to determine where they spend their time, said Christopher Browning, lead author of the study and professor of sociology at The Ohio State University.

“It is clear that kids who live in high-poverty areas are spending less time in their neighborhoods and that is linked to a collective fear of crime,” Browning said.

“This has never been tested before with GPS data that tracks movements on a minute-by-minute basis.”

Browning presented the research Aug. 14 in Montreal at the annual meeting of the American Sociological Association.

This preliminary data is from the Adolescent Health and Development in Context study, which Browning leads. The study is examining the lives of 1,402 representative youths living in 184 neighborhoods in Franklin County, Ohio. This includes the city of Columbus and its suburbs.

In this study, which was conducted April 2014 to July 2016, participating adolescents were given a smartphone that they kept with them for one week. The GPS function on the phone reported their location every 30 seconds.

Overall, results showed youth spent an average of 52 percent of their waking time each day at home, 13 percent in their neighborhoods, and 35 percent outside of their neighborhoods. About 27 percent of the time when they were not at home while awake, they were in their neighborhoods.

All caregivers of youth in the study were asked to rate how afraid they were to walk in their neighborhood.

Results showed that caregivers’ ratings were only weakly connected to how much time their own children spent in the neighborhood. But the collective fear ratings of all the caregivers who lived in or regularly visited a neighborhood was strongly linked to the amount of time kids spent close to home.

“Once enough people stop spending time in a neighborhood because they are afraid, others will withdraw, whether they are afraid or not,” Browning said.

“If teens go to the local playground and there’s no one to play pickup basketball with, they will go outside the neighborhood to find their friends, or spend more time at home.”

The study looked at whether the presence or absence of amenities like schools, community centers and stores could explain why youth in high-poverty neighborhoods spent less time there. But this factor explained little when compared to the collective fear of crime.

“Many cities have social services like recreation centers that are targeted for disadvantaged neighborhoods,” Browning said.

“But our results suggest these amenities may be underutilized because young people are withdrawing from the neighborhood. Whether they are afraid to go there or just following their friends elsewhere, young people spend less time in disadvantaged neighborhoods.”

Upcoming studies using this same data set will examine whether kids in disadvantaged neighborhoods spend their extra time at home, or outside of their area.