Obesity carries with it a multitude of health risks, but now a large study shows that obese adults who were obese as teens have a much greater risk of developing adverse health conditions, including abnormal kidney function, asthma and difficulty walking.

Results of the study, conducted by researchers at Cincinnati Children's Hospital Medical Center and the University of Pittsburgh, were published in the journal Pediatrics.

Dr. Thomas H. Inge, professor of surgery and pediatrics at Cincinnati Children's Hospital Medical Center and co-author of the study, says:

"Most people understand that the longer you carry extra weight, the higher your chances of developing heart disease or diabetes. But it seems that an even larger number of conditions should be added to the list of health problems that some obese teenagers will likely face down the road."

The study involved 1,502 severely obese adults, who were between the ages of 19 and 76.

They were all enrolled in the Longitudinal Assessment of Bariatric Surgery-2 (LABS-2), which is a long-term study following over 2,400 individuals in order to examine the risks and benefits of bariatric (weight loss) surgery in adults. The study is funded by the National Institutes of Health.

Severe obesity is characterized by a body mass index (BMI) of 35 or over, which the researchers say is around 220 pounds for a woman of average height.

Specific teen obesity-related health risks

After reporting their height and weight at age 18, the study participants were evaluated for obesity-related medical conditions.

Of the adults in the study, 42% had a weight in the normal range at age 18, while 29% were considered obese and 13% were considered severely obese. The researchers say 96% of the participants had at least one medical condition as an adult that was related to obesity.

Dr. Inge and his team found that obesity in the teenage years was linked with a greater risk of health problems in adulthood, after taking into account change in BMI since adolescence.

Those participants who were severely obese as teenagers were over four times more likely to have swollen legs and skin ulcers than those who were at a normal weight during the teenage years.

They were also more than three times more likely to have walking limitations and abnormal kidney function.

Additionally, the obese teen group of adults were much more likely to have polycystic ovary syndrome, asthma, diabetes and obstructive sleep apnea, compared with those who were at a normal weight in their teens.

"As the number of children with severe obesity continues to increase," says Dr. Inge, "it is important for pediatricians to inform families about the short- and longer-term health issues linked to this weight gain."

Dr. David R. Flum, co-author and professor of surgery, health services and pharmacy at the University of Washington, adds:

"These findings underscore the importance of interventions in children to prevent the progression to obesity in teenage years and young adulthood. We failed to prevent the progression from normal weight to obesity in four out of 10 adults having bariatric surgery, which is at least in part a manifestation of a sickness-oriented system instead of a wellness-oriented system."

Medical News Today recently reported on a study suggesting that obesity is linked to early onset of puberty in girls.