Adolescent obesity is an increasing public health challenge, leading to metabolic syndrome and chronic diseases. This quasi-experimental study evaluated the impact of school-based physical activity interventions on BMI, waist circumference, and metabolic risk factors among 800 adolescents aged 12–18 years. The intervention included structured exercise sessions, fitness education, and weekly activity tracking over six months. Post-intervention analysis revealed significant reductions in mean BMI (-1.4 kg/m²), waist circumference (-3.2 cm), and fasting blood glucose (-5 mg/dL) compared to baseline (p<0.01). Students also reported improved knowledge about healthy lifestyle habits and increased engagement in extracurricular physical activities. The study underscores the effectiveness of structured school-based interventions in reducing obesity and metabolic risk among adolescents.

Keywords:
Physical Activity, Obesity, Adolescents, Metabolic Risk, Public Health