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Bariatric Surgery for Teens with Severe Obesity Study: Teen-LABS

The NIDDK funded the Teen-LABS (Longitudinal Assessment of Bariatric Surgery) study to look at the short- and long-term risks and benefits of bariatric (weight-loss) surgery in teens. Teen-LABS is the first large-scale study of this procedure in teens who have severe obesity (a much greater-than-normal amount of body fat) and serious weight-related health problems, such as prediabetes, type 2 diabetes, cardiovascular disease (heart and blood vessel disease), sleep apnea (breathing problems during sleep), nonalcoholic fatty liver disease (NASH), or other conditions.

For teens with severe obesity, lifestyle changes such as following a healthy eating plan for weight loss and being more active are important, but if not enough weight is lost to improve health, then additional treatments such as weight-loss surgery may be considered. Weight-loss surgery is being used more often as a treatment for teens who have severe obesity, but more research is needed in this area better understand how effective it is with teens and whether there are risks associated with the surgery.


Three years after weight-loss surgery, researchers found major improvements in weight, heart health, and other measures in teens who were in the study. Participants lost about 90 pounds on average, or 27 percent of their weight. The study found that most of the teens who had type 2 diabetes, prediabetes, high blood pressure, abnormal kidney function, and high blood cholesterol when the study began, showed improvements in these conditions after the surgery. Also, about one-quarter, or 26 percent, of the teens were no longer obese 3 years after surgery. Although most teens still had some level of obesity, not as many had severe obesity.

Researchers also identified some risks from surgery. In the first 30 days after surgery, 8 percent of participants had major life-threatening problems such as needing another abdominal surgery; and 15 percent had minor (non-life threatening) complications, such as going back to the hospital for being dehydrated. During the 3 years after their bariatric surgery, 13 percent of participants needed additional abdominal surgery such as gallbladder removal. Researchers also found that although fewer than 5 percent of participants had low iron levels before surgery, more than half had low iron levels 3 years later. Participants also had lower levels of vitamin A and vitamin B12 as a result of the surgery.

Study Size, Participant Demographics, Study Design, and Follow-up

About 240 teens, ages 13 to 19, were enrolled in the study between 2007 and 2011 at five medical centers:

  • Cincinnati Children’s Hospital Medical Center, Ohio
  • Texas Children’s Hospital, Texas
  • Children’s Hospital of Alabama, Alabama
  • University of Pittsburgh Medical Center, Pennsylvania
  • Nationwide Children’s Hospital, Ohio

Before joining the study, all of the teens made the decision to have weight-loss surgery. While the study did not provide their surgeries, all surgeries took place at one of the Teen-LABS’ clinical locations. Their health was then evaluated as part of the study before and after surgery. The surgeries were performed between 2007 and 2012.

In 2016, NIDDK extended funding for Teen-LABS for several more years to allow the researchers to gain additional information from participants on longer-term benefits and risks from the surgery. For example, researchers will assess

  • how long the weight loss lasts.
  • whether improvements in quality of life, diabetes, blood pressure, and other conditions are long lasting.
  • whether other health problems occur.

Research findings on the longer-term health outcomes of weight-loss surgery will guide treatment decisions to improve the health of teens with severe obesity.

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