Obesity could be a contagious model for teenagers


Teens who live around lots of obese or overweight kids come to see their body types as ideal, a new study suggests.

As a result, these teens tend to be obese or overweight themselves, researchers say.

Higher obesity rates may normalize unhealthy weight in teens and make obesity prevention harder,” said lead researcher Ashlesha Datar. She’s a senior economist at the Center for Economic and Social Research at the University of Southern California, in Los Angeles.

For the study, Datar’s team collected data on 401 teens who took part in a study of U.S. Army families between December 2017 and July 2018. Young people and their parents completed online surveys about teens’ height, weight and other factors.

The young people were presented a set of human figures of varying sizes and asked to choose which was closest to their ideal.

“Teens who were located in counties with higher obesity rates were more likely to choose a figure that reflected a larger body size, compared to teens who were located in counties with lower obesity rates,” Datar said.

She said a key strength of the study is that teens were exposed to counties with higher or lower obesity rates due to their parent’s military assignment, creating a natural experiment to see how exposure to obese communities influences body size norms and obesity risk.

Datar said she’s not sure what can be done to compensate for teens’ environment and get them to model healthier body types.

“Perhaps educating teens about unhealthy weight and ways to deal with social pressure and norms surrounding body size can help,” she suggested.

Dr. David Katz is president of the True Health Initiative, which promotes healthy lifestyles. He was not involved with the study, but he reviewed the findings.

“There is both comfort and discomfort in the idea that seeing a lot of obesity among those all around you effectively ‘normalizes’ the appearance of overweight for young people,” Katz said.

The comfort is that young people may feel more comfortable with the skin they’re in and less prone to harsh self-judgment and adverse effects of obesity on self-esteem, he said.

“If obesity normalizes in social networks, it may also serve to destigmatize it and alleviate the historical burden of bullying and abuse. This is all very much for the good,” Katz said.

But obesity is a major risk factor for type 2 diabetes, fatty liver and many major chronic diseases, which can begin at or before adolescence, he noted.

Normalizing obesity might induce apathy about preventing and managing it, which could come at a high cost to health, Katz warned.

“We should strive to end blaming the victims of epidemic obesity, but at the same time, we should acknowledge the attendant health toll and increase our culture-wide efforts to manage and prevent this eminently preventable public health scourge,” he said.

Katz doesn’t think parent oversight is the solution to the obesity epidemic. He said it’s up to health professionals to teach adults and kids alike that excess weight is an important health risk.

“I would not encourage parents to say: ‘No, you are wrong – your weight is not ideal,'” he said. “We already know parents are prone to the same distortions. I coined the term ‘oblivobesity’ based on the parental tendency to overlook and deny obesity in their own kids.”


As with adults, obesity has been rising among children over the last several decades. Between the 1976–1980 NHANES survey and the 2015–2016 survey, obesity rates for children ages 2 to 19 more than tripled, up from 5.5 to 18.5 percent.

In the last decade, the increase has slowed, with no statistically significant changes between 2007–2008 and 2015–2016.

These high childhood obesity rates, however, are not promising for future adult obesity rates, since children who are overweight or who have obesity are more likely to have obesity as adults, too.

As such, targeting interventions that will help families and children have access to healthy, affordable foods and safe places for physical activity is a promising strategy to start addressing America’s obesity epidemic.

Recently researchers have focused specifically on the first 1,000 days of life as a critical time to encourage healthy nutrition (including breastfeeding, responsive feeding, delay of complementary food, and no juice or milk for infants under age 1).

It’s also an opportunity for family interventions that benefit parents as well as children.

This section includes the latest data available on childhood obesity. As with adults, this report relies on multiple surveys to better understand the full picture of childhood obesity.

National Childhood Obesity Rates

The most recent national data, the 2015–2016 NHANES survey, found that percent of children ages 2 through 19 had obesity. The prior section covers differences by race and ethnicity (starting on page 10). Some other demographics available include:

Sex: Boys are slightly more likely to have obesity than girls.

  • From 2015 to 2016, 19.1 percent of boys had obesity and 17.8 percent of girls had obesity.
  • Between 2013–2014 and 2015–2016, the obesity rate of boys went up 11 percent, while the rate among girls with obesity went up 4 percent.86

Age: The prevalence of obesity and severe obesity increases with age.

  • In 2015–2016, 13.9 percent of children ages 2 to 5, 18.4 percent of children ages 6 to 11, and 20.6 percent of children ages 12 to 19 had obesity.
  • Nearly 2 percent of children ages 2 to 5, 5.2 percent of children ages 6 to 11, and 7.7 percent of children ages 12 to 19 had severe obesity.
  • Between the 1976–1980 NHANES survey and the 2015–2016 survey, the percentage of children ages 2 to 19 with obesity overall tripled, with obesity among children ages 6 to 11 doubling, and the obesity rates of teens ages 12 to 19 quadrupling.

Early Childhood Obesity Rates

According to WIC data, the percentage of children ages 2 to 4 enrolled in the program who had obesity continued to decline, from 15.9 percent in 2010 to 13.9 percent in 2016, compared with increases between 2000 and 2010. The reductions were widespread – rates decreased among children across age, sex, major racial and ethnic groups, and in 34 of 56 state WIC agencies. The obesity rates among all children enrolled in WIC are now in line with the general population of children in the United States.

However, certain races and ethnicities have much higher obesity rates.

Specifically, in 2016, 18.5 percent of AI/ AN and 16.4 percent of Latino children who were enrolled in WIC had obesity, compared with 12.1 percent of White, 11.4 percent of Black and 10 percent of Asian and Pacific Islander children

Obesity Rates in Children Ages 10 to 17

The NSCH reported that nationwide, for their 2016–2017 survey, 15.8 percent of children ages 10 to 17 had obesity and 15.2 percent were overweight.

The states with the highest rates of obesity for children ages 10 to 17 were Mississippi (26.1 percent), West Virginia (20.3 percent), and Kentucky (19.3 percent); the states with the lowest rates of obesity were Utah (8.7 percent), New Hampshire (9.8 percent), and Washington state (10.1 percent). See chart on page 32 for more state data.

High School Obesity Rates

According to 2017 YRBS data, 14.8 percent of high school students (grades 9 through 12) nationwide had obesity and 15.6 percent were overweight.

In 2015, YRBS found 13.9 percent of high schoolers had obesity and 16 percent were overweight. Obesity levels among high school students show a statistically significant increase in the  long-term; in 1999, obesity rates among high schoolers participating in the survey were at 10.6 percent.

Other takeaways include:

  • High schoolers who were male (17.5 percent); Black (18.2 percent); Latino (18.2 percent); or lesbian, gay, or bisexual (20.5 percent) had particularly high levels of obesity in 2017.
  • The levels of obesity among high school students in different states varied considerably—from 9.5 percent in Colorado to 21.7 percent in Arkansas.
  • States with the highest levels of obesity were: Arkansas (21.7 percent), Kentucky (20.2 percent), Tennessee (20.5 percent), and West Virginia (19.5 percent).
  • States with the lowest obesity rates were: Colorado (9.5 percent), Florida (10.9 percent), Idaho (11.4 percent), Massachusetts (11.7 percent), Montana (11.7 percent), and Utah (9.6 percent).

See page 32 for state-by-state data on obesity, overweight, and activity levels among high school students.

More information: To learn more about teenage obesity, visit the American Academy of Child and Adolescent Psychiatry.


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