Our results show that increasing weight status in children and adolescents is associated with a general reduction in lung volume measurements, which may reflect impaired lung function, increased respiratory symptoms, and decreased functional status.

A pproximately two million Canadian boys and girls are overweight or obese (1,2), which places them at increased risk for several chronic diseases. Overweight and obese children referred for weight management often exhibit suboptimal lifestyle behaviours (3) -a finding that highlights the potential for interventions to promote healthier habits. These observations, along with recent clinical practice guidelines (4) and best practice recommendations (5), underscore the importance of healthy lifestyle behaviours as the cornerstone of paediatric weight management. Even in situations for which more intensive therapy may be indicated, nutrition, physical activity and behavioural counselling remain foundational strategies (6,7).Evidence supporting the successful treatment of paediatric obesity is primarily derived from group-based interventions, which tend to be more efficacious (8) and cost effective (9), and reduce attrition (10) versus one-on-one care. Alternately, one-on-one care is more feasible, appropriate (in some situations) and common in many Canadian paediatric weight management clinics (11). A key limitation of the aforementioned research is that most studies included community-based volunteers -a situation that differs for many paediatricians who refer obese boys and girls to multidisciplinary weight management clinics. Recently, the Canadian Institutes of Health Research (CIHR) emphasized the value of integrating research into practice-based settings as a way to enhance health services for Canadians (12). We believe that offering one-on-one interventions in clinics that provide paediatric weight management care and conduct applied research in real-world environments can inform health service delivery ) that does not include these techniques; and to determine whether the HIP and YLP interventions are superior to a wait list control (WLC) group. METHODS: Obese adolescents were randomly assigned to a YLP (n=15), HIP (n=17) or WLC (n=14) group. The YLP and HIP were 16-session, one-on-one interventions. The primary outcome was the percentage change of body mass index z-score. RESULTS: Completers-only analyses revealed 3.9% (YLP) and 6.5% (HIP) decreases in the percentage change of body mass index z-score compared with a 0.8% (WLC) increase (P<0.001). Levels of attrition did not differ among groups, but were relatively high (approximately 20% to 40%). CONCLUSION: Lifestyle interventions delivered in a real-world, clinical setting led to short-term improvements in the obesity status of adolescents.