Predictors of successful weight reduction and maintenance in obese children and adolescents

Obesity has become one of the most serious public health concerns of the 21st century, and its development is influenced by a complex interplay of genetic, behavioural (1) and socio-economic (2) factors in paediatrics. The dramatic increase in the worldwide prevalence of paediatric obesity, including in Israel (3), has led to the increasing appearance of obesity-related comorbidities at an early age (4). Lifestyle interventions, including counselling and education, are considered the therapy of choice for obese children and adolescents, with implications for reducing insulin resistance and other markers of cardiovascular risk. Nevertheless, studies only report limited, short-term efficacy, with heterogeneous outcomes in clinical practice (5) and a high rate of regained weight in the long term (6). This study focuses on variables related to a positive response to lifestyle interventions and what is already known (7–11). Our aim was to identify baseline variables that can predict successful weight reduction in response to lifestyle interventions in obese children and adolescents. The study was conducted in the obesity clinic of the Institute of Endocrinology and Diabetes at Schneider Children’s Medical Center, Israel, a tertiary, universityaffiliated hospital. The computerised clinic database was retrospectively searched for patients under the age of 19 with a body mass index (BMI) above the 95th percentile for age and gender who were referred for evaluation and treatment between July 2007 and July 2012. Only patients who had made at least three clinic visits with at least one year of follow-up were included to evaluate the shortand long-term impact of standard interventions on weight reduction. The exclusion criteria were the presence of any syndrome or disease known to affect body composition or fat distribution such as Cushing’s syndrome, hypothyroidism or craniopharyngioma, the use of anti-obesity medications or other medications that can affect body weight, current or prolonged steroid therapy and a history of bariatric surgery. The following patient data were obtained from the medical records: age, gender, ethnicity, birthweight, age at first visit to the obesity clinic, presence of concomitant illnesses, use of medication, presence of known obesity-related comorbidities such as dyslipidaemia, type 2 diabetes or impaired glucose tolerance, hypertension, obstructive sleep apnoea, nonalcoholic fatty liver disease, pseudotumor cerebri, orthopaedic problems, menstrual disorders/polycystic ovaries (for adolescent girls), previous participation in a dietary weight-reduction intervention programmes and self-reported data of participation in physical activity on a regular basis at least once a week for at least 60 minutes each time. The family data included were as follows: parental height, BMI, education, marital status, number of siblings at home and firstdegree relatives with cardiometabolic disorders associated with obesity. Data collected on routine assessment at each clinic visit included documentation of obesity-related comorbidities, findings on physical examination, anthropometric measurements and laboratory tests. The presence of acanthosis nigricans was noted. Measurement of blood pressure was taken after the subject had rested for five minutes in the Abbreviations BMI, Body mass index; SDS, Standard deviation score.