Impact of significant weight loss on maximal oxygen uptake in obese children and adolescents

Background: The prevalence of pediatric obesity has increased over the past few decades in all ethnic, gender, and age groups, The treatment of obesit y, especially in children with moderate to severe conditions, is difficult, In this study, we examined the impact of significant weight loss as a resu lt of participation in a multi-disciplinary weight management program on ma ximal oxygen uptake (VO(2)max) in obese children and adolescents, Methods: Eleven obese children and adolescents (7 to 14 years of age; mean age, 12.3+/-1.9 years) were enrolled in a weight management program at the Children's Hospital of New Orleans, The treatment program included a high-p rotein, very low-calorie diet (VLCD; protein intake, 1.5 to 2.0 g/kg of ide al body weight per day; and 800 kcal/d), Diets were supplemented with extra fluid, minerals, and vitamins, All subjects attended weekly 2-hour clinic sessions, During these sessions, they received nutrition instruction, parti cipated in a moderate-intensity, progressive exercise program, and learned behavior-modification techniques. Weight, height, body mass index ([BMI]; w t/ht(2)), and VO(2)max by indirect calorimetry were obtained at enrollment and at the end of 10 weeks of treatment, Results: There was a significant decrease in body weight after 10 weeks, Th e BMI decreased significantly from 34.1+/-4.8 on entry to 29.4+/-3.5 (mean/-SD; P<0.0001), Despite the significant weight loss, VO(2)max increased si gnificantly (P<0.001) from entry (19.2+/-3.0 mL/kg/min) to completion of 10 weeks (22.4+/-5.8 mL/kg/min). However, absolute VO(2)max L/min was unchang ed, Conclusions: We conclude that relative VO(2)max mL/kg/min is significantly improved in obese youth after significant weight loss with a VLCD and moder ate-intensity, progressive exercise, However, because absolute VO(2)max L/m in was unchanged, this improvement seems to result from the reduction in to tal body weight as opposed to the effect of the moderate-intensity exercise intervention.