Abstract
BACKGROUND: The rising prevalence of severe obesity among children and adolescents poses a major public health challenge. PURPOSE: In this study, we examined the differences in body composition and physical fitness between obese and severely obese Asian youth and evaluated their responses to a customized lifestyle intervention. METHODS: A total of 136 overweight and obese participants (mean age, 11.5±3.0 years) were enrolled in an individualized lifestyle modification program. The participants were stratified by obesity severity, with severe obesity defined as a body mass index (BMI)-for-age ≥120% of the 95th percentile. Body composition and physical fitness were assessed at baseline and after 3 interventional stages. The results were compared between the severely obese group and nonseverely obese group, and the relationships between the changes were analyzed. RESULTS: Among the obese participants, 46% met the criteria for severe obesity. At baseline, those with severe obesity demonstrated a lower performance percentile in the 1-minute sit-up test (22.1±25.2 vs. 47.9±28.0, P=0.002) and the standing long jump (8.5±14.6 vs. 26.8±23.2, P= 0.003) than their nonseverely obese peers. Participants in both groups showed significant reductions in body fat percentage and preserved skeletal muscle mass after the intervention. Those in the severely obese group achieved greater reductions in weight, BMI, BMI z score, and fat mass, particularly during the first 2 interventional stages, indicating a stronger response to the program. CONCLUSION: The severely obese youth showed poorer baseline physical fitness levels but greater improvements in key obesity-related measures following the lifestyle interventions. These findings highlight the potential benefits of early targeted interventions for this high-risk group.