Obesity Surgery

, Volume 24, Issue 4, pp 487-519

First online:

Bariatric Surgery in Class I Obesity

A Position Statement from the International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO)
  • Luca BusettoAffiliated withDepartment of Medicine, University of Padua Email author 
  • , John DixonAffiliated withClinical Obesity Research, Baker IDI Heart & Diabetes Institute
  • , Maurizio De LucaAffiliated withDepartment of Surgery, San Bortolo Hospital
  • , Scott ShikoraAffiliated withCenter for Metabolic and Bariatric Surgery, Brigham and Women’s Hospital
  • , Walter PoriesAffiliated withBrody School of Medicine, East Carolina University
  • , Luigi AngrisaniAffiliated withGeneral And Endoscopic Surgery Unit, San Giovanni Bosco Hospital

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Class I obesity conveys an increased risk of comorbidities, impairs physical and mental health-related quality of life, and it is associated to an increased psychosocial burden, particularly in women. The need for effective and safe therapies for class I obesity is great and not yet met by nonsurgical approaches. Eligibility to bariatric surgery has been largely based on body mass index (BMI) cut points and limited to patients with more severe obesity levels. However, obese patients belonging to the same BMI class may have very different levels of health, risk, and impact of obesity on quality of life. Individual patients in class I obesity may have a comorbidity burden similar to, or greater than, patients with more severe obesity. Therefore, the denial of bariatric surgery to a patient with class I obesity suffering from a significant obesity-related health burden and not achieving weight control with nonsurgical therapy simply on the basis of the BMI level does not appear to be clinically justified. A clinical decision should be based on a more comprehensive evaluation of the patient’s current global health and on a more reliable prediction of future morbidity and mortality. After a careful review of available data about safety and efficacy of bariatric surgery in patients with class I obesity, this panel reached a consensus on ten clinical recommendations.


Class I obesity BMI Eligibility