While bariatric surgery is established as a safe and effective alternative with well-defined risks for severely obese adults, little has been published on its use in children.

There are many unresolved questions concerning the long-term metabolic and psychological consequences of bariatric surgery in adolescents, and the difference with the adult population. The appropriate timing for bariatric surgery in young people, and the predictors of success and safety still need to be determined.

The aim of this long-term prospective study is therefore to establish the safety and efficacy profile of surgical procedures and to clarify whether reductions in morbidity and mortality outweigh the risks of serious surgical complications and lifelong nutritional deficiencies.

The investigators will conduct a prospective observational cohort design study to collect data during standard clinical care of adolescent bariatric patients (younger than 18 years) who were operated (RYGB or SG) for weight loss.

Medical, psychological, behavioral, fitness and social data will be collected by medical personnel guided by checklists and prepared questionnaires. All non-invasive and invasive examinations will be performed following the existing protocol of the multidisciplinary group at the hospital (no alteration of normal standard care). Data regarding family environment (birthdays, weight, length, medication, comorbidities, smoking and education of parents and siblings) will also be obtained from caregivers of the patients.

Inclusion Criteria:

• BMI (or projected BMI) > 40 kg/m² (projected BMI = weight over the age- and gender-specific BMI z-score defined as severe obesity corresponding at a projected BMI of 40 at the age of 18y) OR
• BMI ((or projected BMI) > 35 kg/m² (projected BMI = weight over the age- and gender-specific BMI z-score defined as severe obesity corresponding at a projected BMI of 35 at the age of 18y) + 1 or more of the following obesity-related comorbid conditions: Obstructive Sleep Apnea Syndrome, Non-alcoholic steatohepatitis, type 2 diabetes, hypertension, benign intracranial hypertension.
• Minimum 6 months of organized weight loss attempts before surgery (multidisciplinary follow-up)
• Completed most of their linear growth (Tanner stage ≥ IV, bone age ≥ 13 years in girls and ≥ 14 years in boys assessed by the Tanner and Whitehouse method)
• Capability and willingness to adhere to postoperative guidelines and prolonged surveillance
• Informed Consent Form (ICF) signed by patient and parents (or legal guardian)

Exclusion Criteria:

• psychological/psychiatric disorders that are decompensated or not efficiently treated
• severe and unstable eating disorders (e.g. binge-eating)
• signs of addictions or addictive behavior (alcohol or substance abuse)
• pregnancy or breastfeeding
• life-threatening multisystem organ failure
• uncontrolled or metastatic malignancy
• uncontrolled HIV infection
• hypercarbic respiratory failure
• active systemic infection or untreated endocrine dysfunction
• diseases threatening in the short term or lack of care (self-care or access to family or social support)
• medically correctable causes of obesity

primary care clinic