The older teens get, the more likely they are to pack on pounds, and obesity rates climb sharply between adolescence and young adulthood, finds a new study from Australia.
"Being obese as an adolescent is bad news. If an adolescent gets to the point of being obese, the likelihood of spontaneous recovery to normal weight by young adulthood is small," said George Patton, M.D., director of the Centre for Adolescent Health at the Murdoch Childrens Research Institute in Victoria.
Between 1992 and 2003, Patton and colleagues tracked the height, weight and body mass index (BMI) of 1,520 teens, starting at age 14 and continuing through age 24.
By mid-adolescence, one in five teens was overweight, but by age 24, that proportion increased to one in three. Forty percent of overweight young adults had never even been overweight during the teens, the authors reported in the study, which appears in the latest issue of the Journal of Adolescent Health.
"For the group who were consistently obese as teenagers, over 60 percent were still obese, and none got to a normal healthy weight," Patton said.
Kerri Boutelle, Ph.D., associate professor of pediatrics and psychiatry at the University of California, San Diego, said the study is remarkable because it is one of few to track teens from adolescence into adulthood.
"What you don't know about this study is whether those kids in adolescence were trying to do anything about their weight. The assumption is that everyone who's overweight is trying, but we don't know if any of those teenagers have access to effective ways to lose weight," Boutelle said. She had no affiliation with the study.
There are some grounds for optimism for teens with weight concerns, however. Teens who were overweight for less than a year in adolescence generally had returned to a normal weight by young adulthood, particularly among girls.
"Only 30 percent of this group of girls was still overweight compared with 60 percent of boys. This suggests that in this group, lifestyle interventions such as eating sensibly and exercising may work well," Patton said.