Physical activity may slightly reduce body weight, waist size, and body fat percentage among adolescents with obesity, though researchers caution that larger, longer-lasting, and better-quality studies are necessary to be more certain about the effects. Since 1990, health statistics reveal that worldwide obesity levels among youth aged 10 to 19 have multiplied by three, with projections suggesting upwards of 300 million children and adolescents could be affected by obesity come 2050. Mental and physical well-being can suffer due to obesity in youth, which also elevates the chances of developing kidney disease, liver disease, or cancer in later life.
Lifestyle changes such as doing more physical activity and eating healthier foods, or surgery or medication, are used for weight loss. To investigate the impact of physical activity, recent scientific reviews evaluated controlled trials comparing active programs against no physical activity. The results indicate that while certain measurements see improvement, the impact of physical activity on other health complications, body dimensions, or weight indicators remains unclear.
Examining the evidence reveals physical changes in young participants. Investigators analyzed data from 30 studies encompassing 1,508 adolescents across 15 countries, including Tunisia, China, Iran, Brazil, Canada, Spain, the USA, Australia, Estonia, India, Mexico, South Korea, Sweden, Taiwan, and Thailand. Female participants accounted for 46 percent of the total group, with average ages ranging from 10 years to nearly 17 years.
When comparing structured physical activity against no activity, pooled data from 17 studies involving 749 adolescents demonstrated that active participants weighed an average of 1.88 kg less. Furthermore, data from 10 studies covering 476 adolescents showed an average waist size reduction of 2.88 cm, while 9 studies involving 313 adolescents indicated a 2.96 percent lower body fat percentage. Researchers are very uncertain about the effect of any type of physical activity on BMI, BMI z-score, blood sugar levels, insulin resistance, and unwanted, harmful events.
Evaluating Exercise Types and Study Limitations
Researchers examined 17 studies comparing one type of physical activity to another. Based on the evaluation, researchers remain extremely unclear regarding how different forms of physical activity compare against each other across any of their observed criteria, and they cannot determine if one exercise category outperforms another.
Several limitations constrain confidence in these findings. The studies were small, ranging from 21 participants to a maximum of 106. Trial durations were mostly 12 or 13 weeks, with the longest extending to 32 weeks. Inconsistent reporting of methods and findings, incomplete data, and a lack of reports on unwanted, harmful events further complicated the analytical process.
Public Health Implications and Future Research Needs
Addressing adolescent obesity involves strategies such as physical activity and eating healthier foods, or with surgery or medication. The medical community stresses that future scientific investigations must be larger, longer-lasting, and of better quality to be more certain about the effects of physical activity on adolescents with obesity. This evidence is current to December 2025.
Readers seeking further official health guidance or updates on clinical trials can consult public health portals or national medical research registries. We invite our readers to share their perspectives or join the discussion in the comments section below.
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