A new study shows that teens who are overweight or obese may be more likely to develop type 2 diabetes or have a heart attack in their 30s and 40s.
These teens are also more likely to have other health issues down the road, regardless of whether they shed any excess weight during adulthood.
"Adolescence is an important time period to prevent future diabetes and heart attacks," said study author Dr. Jason Nagata, an assistant professor of pediatrics in the division of adolescent and young adult medicine at the University of California, San Francisco.
Exactly how adolescent weight affects your future health is not fully understood yet, but risk factors that begin to accrue at younger ages—such as hardening of the arteries or insulin resistance—may be difficult to fully reverse.
For the new study, the researchers analyzed data on 12,300 adolescents who were followed for 24 years as part of the U.S. National Longitudinal Study of Adolescent to Adult Health. The investigators tracked body mass index (BMI) z-scores. BMI is a measure of body fat based on height and weight, and the z-score puts it into perspective based on a child's age and sex.
When compared with teens who had lower BMI-z scores, adolescents with higher scores had a nearly 9% increased risk for developing type 2 diabetes, a 0.8% greater risk for having a heart attack in their 30s and 40s, and a 2.6% higher risk for being in overall poorer health, and this held regardless of their adult BMI. The researchers also controlled for other factors known to affect health outcomes, such as race/ethnicity, tobacco and alcohol use.
"Parents should encourage teenagers to develop healthy behaviors, such as regular physical activity and balanced meals," Nagata said. Doctors should also consider BMI history in their evaluations, he added.
The findings were published online June 21 in the Journal of the American College of Cardiology.
The message is clear: "We need to act sooner," said Dr. Andrew Freeman, director of cardiovascular prevention and wellness at National Jewish Health, in Denver. He is also the co-chair of the American College of Cardiology's Nutrition & Lifestyle Workgroup.
"What you eat early in life has an impact on what happens to you down the road," said Freeman, who was not involved with the new research. "Rather than pay things lip service, we need to say, "Here's what you need to do and here's how to do it.'"
Making healthy lifestyle changes may help stop some of these risks in their tracks. "Eat a low-fat, whole food, plant-based diet, as every study ever done shows that this way of eating reduces disease and helps people maintain or lose weight," Freeman said. Daily exercise is also an important part of a healthy lifestyle.
Parents should encourage healthy habits, such as family walks and cooking and shopping for healthy foods together, added Dr. Scott Kahan, director of the National Center for Weight and Wellness, in Washington, D.C.
"When kids do gain weight, take steps in smart and supportive ways to help minimize the weight gain and encourage a healthier lifestyle," said Kahan, who was not involved with the new study.
You are not powerless, he said. Losing weight—even just a little bit—will improve your health. "You can reverse some damage that's been done, but you may not be able to reverse it entirely," Kahan said.