July 1, 2021 -- Teenagers with obesity were more likely than their slimmer peers to have a heart attack, type 2 diabetes, or (self-reported) poor health when they were in their 30s and 40s, a new study says.
Previous studies have reported worse health outcomes in older adults, but this is one of the first to look at risk in younger adults.
The teens with obesity were also more likely than other teens to still have obesity 24 years later, as well as high cholesterol, high blood pressure, kidney disease, heart failure, cancer, asthma, and sleep apnea.
The results are from a large U.S. study that examined how obesity at ages 11 to 18 affects health at ages 33 to 43.
The findings show that "adolescence is an important time period to prevent future diabetes and heart attack," says lead author Jason M. Nagata, MD.
"Parents should encourage teenagers to develop healthy behaviors such as regular physical activity and [eating] balanced meals," says Nagata, an assistant professor of pediatrics in the Division of Adolescent and Young Adult Medicine at the University of California, San Francisco.
"Teenagers should know that being active, joining sports teams, and doing physical activity with friends" is important, he says.
Pediatricians, too, can help guide and support teenagers and their families to develop healthy habits, and doctors should ask young adults about their weight history when they are evaluating them for risk of heart disease.
But Nagata, who also treats adolescents with eating disorders, says that "while I think it's important to adopt healthy behaviors -- like a balanced diet and regular physical activity -- I would discourage any teenagers from trying more extreme or disordered eating behaviors for weight loss.”
Other studies have shown that "when you use some of these distorted eating behaviors [including crash diets], people actually tend to gain more weight in the long run," he says.
The study was published online June 21 as a research letter in the Journal of the American College of Cardiology.
Teen Years a Time to Prevent Diabetes, Heart Attack
About 1 in 5 teenagers in the United States has obesity.
That is, they have a body mass index (BMI) score -- a measure of body fat based on height and weight and accounting for age and sex -- that is higher than 95% of other teenagers of the same age, sex, and height.
The researchers tracked 12,300 teenagers who were part of the National Longitudinal Study of Adolescent to Adult Health.
They determined the BMIs of the teens when they were 11 to 18 years old in 1994 and 1995, and then looked at health outcomes when the teens were 33 to 43 years old in 2016 and 2018 (about 24 years later).
About half of the teenagers were female, and about two-thirds were non-Hispanic white. They had a mean BMI of 22.5 kg/m2, which indicates obesity in teenagers but is a normal BMI in adults.
Having obesity as a teenager was linked to greater odds of having high blood pressure, high cholesterol, asthma, cancer, kidney disease, sleep apnea, and premature heart failure, but not stroke -- after adjusting for age, sex, race/ethnicity, education, income, smoking, and alcohol use.
“Compared to a teenager without obesity, a teenager with obesity is 2.73 times more likely to develop diabetes, 2.19 times more likely to have a premature heart attack, and 1.57 times more likely to report poor adult health,” Nagata says.
"In general, teenagers who have a higher BMI are more likely in adulthood to have a higher BMI, and that is associated with these risks, " he says.
Finding no added risk of stroke in young adults who had obesity as teenagers might be because the rate of stroke is so low in young adults, he says.