Two recently published studies have found that gastric bypass surgery is helpful for severely obese teenagers in weight loss and keeping it off. These are the first long-term follow-up studies of teenagers who had had the procedure 5-12 years earlier.

On the downside, the studies also found that some patients will likely need further surgery to deal with the complications of rapid weight loss or may develop vitamin deficiencies later in life.

Until now, it had remained unclear how successful the surgery is in the long-term, or if it can lead to complications. Thousands of teenagers are offered the surgical treatment each year despite the lack of such data.

Severe Obesity

Affecting around 4.6 million children and teenagers in the USA, severe obesity is classified as having a BMI of 40 or over. It amounts to an average of about 100 pounds overweight, and causes ill health, poor quality of life and cuts life expectancy.

Both the papers demonstrate that gastric bypass dramatically reduced the teenagers’ weight and helped them maintain weight loss over more than five years of follow-up.

But the procedure was associated with the development of vitamin D and B12 deficiencies and mild anemia, and some of those who had a bypass needed further surgery to deal with complications. Although the surgery resulted in dramatic weight loss and BMI reductions, many of the teenagers remained obese, meaning that earlier intervention may be needed coupled with lifestyle changes such as diet and exercise.

HealthGrove | Graphiq

Lead author Dr Thomas Inge, Cincinnati Children’s Hospital Medical Center, USA, said:

“Weight loss is crucial for severely obese patients who face poor health and shorter lifespans. These two manuscripts clearly document long-term benefits of adolescent bariatric treatment, but also highlight several nutritional risks.

Now it is important to focus on delivery of the substantial health advantages of surgery while minimizing these risks. Since there are currently two effective bariatric procedures, namely gastric bypass and vertical sleeve gastrectomy, we are currently examining the outcomes of both procedures to determine what is best for adolescents."

Important Data

Professor Geltrude Mingrone of Catholic University in Italy, in a separate commentary, wrote:

“Unfortunately, hypocaloric diet, lifestyle modification, and medical treatment do not have much of an effect in adolescent populations because of poor adherence. Additionally, intensive behavioural weight loss interventions that are effective at reducing BMI in adolescents who are overweight or obese have diminished effectiveness for those with severe obesity.

Before now, only a few short-term studies of bariatric surgery in adolescents have been reported; therefore, these studies provide important data and shed new light on the use of bariatric surgery in young people.

Undoubtedly, no other approaches but bariatric surgery are able to provide such considerable weight loss, with only relatively small weight regain, over time. In view of the significant vitamin D deficiency reported by both Inge and colleagues and Olbers and colleagues, and the possibility of early surgery affecting growth, it is important that future national guidelines address the matter of the age at which bariatric surgery should be performed in adolescents."

Funding came from Ethicon Endosurgery, National Center for Advancing Translational Sciences (US National Institutes of Health), Swedish Research Council; Swedish Governmental Agency for Innovation Systems; National Board of Health and Welfare; Swedish Heart and Lung Foundation; Swedish Childhood Diabetes Foundation; Swedish Order of Freemasons Children’s Foundation; Stockholm County Council; Västra Götaland Region; Mrs Mary von Sydow Foundation; Stiftelsen Göteborgs Barnhus; Stiftelsen Allmänna Barnhuset; and the US National Institute of Diabetes, Digestive, and Kidney Diseases (National Institutes of Health).

Inge, Thomas H et al. Long-term outcomes of bariatric surgery in adolescents with severe obesity (FABS-5+): a prospective follow-up analysis The Lancet Diabetes & Endocrinology DOI:

Olbers, Torsten et al. Laparoscopic Roux-en-Y gastric bypass in adolescents with severe obesity (AMOS): a prospective, 5-year, Swedish nationwide study The Lancet Diabetes & Endocrinology DOI:

Image: Anne-Katrin Purkiss, Wellcome Images

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