‘Complex severe obesity’ in children and adolescents can be defined as a BMI >95th percentile for their age and
gender in addition to at least one significant obesity-related co-morbidity requiring specialty care, other co-existing
chronic illness impacted by obesity, or a BMI ≥99th percentile for their age and gender. These children are at high risk of
acute and long-term medical and psychosocial morbidities. Optimal management strategies for this group of patients are
not well studied, although general principals include emphasis on a comprehensive family-based lifestyle intervention,
while addressing medical and psychological aspects of obesity, as well as motivation to change behaviours. Further
treatment options, such as bariatric surgery, may be necessary, but require a skilled interdisciplinary team and careful
selection of candidates most likely to benefit from these procedures.