Physical activity for the management of obesity in adolescents aged 10 to 19 years

Obesity is a global public health issue and a major contributor to non-communicable diseases. In recent decades, the prevalence of obesity in adolescents has risen at an alarming rate. Although several systematic reviews have evaluated the effects of physical activity for the management of obesity in adolescents, key limitations remain in the literature, particularly in reporting completeness and the lack of standardised assessments of the certainty of evidence.

To synthesise evidence on the benefits and harms of physical activity interventions for the management of obesity in adolescents aged between 10 and 19 years.

We searched various databases, including the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid), Embase (Ovid), and two trial registries, from 2012 to 4 December 2025. We applied no restrictions on language or publication status. We also searched grey literature sources.

We included randomised controlled trials (RCTs) that evaluated physical activity interventions lasting at least 12 weeks, of any frequency, type, or intensity, in adolescents aged 10 to 19 years with obesity (as defined by study investigators) at baseline. Eligible comparators included standard care, waiting list, no physical activity, or any other active interventions, such as a comparison of different physical activity parameters (duration, frequency, intensity).

Critical outcomes: body weight, body mass index (BMI), BMI z-score, waist circumference, body fat percentage, glucose, and insulin resistance. Important outcomes: physical well-being, mental well-being, physical activity levels, overall quality of life, blood pressure, adiposity, lipid biomarkers, insulin, fasting glucose, mortality, adverse events, presence of obesity-related comorbidities or any non-communicable disease, disability, prevalence of obesity in adulthood, alterations in hunger, and access to health services.

Pairs of review authors independently assessed the risk of bias in each included study using the original version of the Cochrane tool (RoB 1).

We synthesised results using meta-analysis when appropriate. Given the clinical and statistical heterogeneity, we predominantly used a random-effects model alongside sensitivity analyses. When meta-analysis was not feasible, we employed synthesis without meta-analysis (SWiM) methods. We assessed the certainty of the evidence using the GRADE approach. We grouped eligible comparisons into two broad categories: (1) physical activity intervention versus no-intervention control; and (2) one physical activity intervention versus another physical activity intervention or an active control. The first category is our main comparison.

We included 30 studies (1508 participants) conducted across 15 countries, published between 2012 and 2023 (median year: 2017), with participants' ages ranging from 10 to 17 years. We assessed all included studies to be at high risk of bias.

Physical activity intervention versus no-intervention control In adolescents with obesity aged 10 to 19 years, low-certainty evidence suggests that any form of physical activity may slightly improve the following outcomes compared to no intervention: body weight (mean difference (MD) -1.88 kg, 95% confidence interval (CI) -3.34 to -0.42; I² = 47%; 17 studies, 749 participants); waist circumference (MD -2.88 cm, 95% CI -3.70 to -2.06; I² = 0%; 10 studies, 476 participants); and body fat percentage (MD -2.96%, 95% CI -3.52 to -2.39; I² = 10%; 9 studies, 313 participants). This review identified very low-certainty evidence regarding the effects of any form of physical activity on BMI (MD -1.38 kg/m², 95% CI -1.94 to -0.83; I² = 43%; 16 studies, 537 participants), BMI z-score (MD 0.01 z-score units, 95% CI -0.34 to 0.37; I² = 84%; 6 studies, 250 participants), glucose (MD -0.29 mmol/L, 95% CI -0.45 to -0.12; I² = 76%; 7 studies, 299 participants), and insulin resistance (MD -0.99, 95% CI -1.25 to -0.73; I² = 66%; 6 studies, 256 participants). Compared to no intervention, any form of physical activity may improve mental well-being, based on evidence from one study with 56 participants (self-perception: MD 0.22, 95% CI -0.10 to 0.54; self-efficacy: MD 0.58, 95% CI 0.21 to 0.95; self-esteem: MD 0.47, 95% CI 0.18 to 0.76). We identified low- or very low-certainty evidence for other important outcomes, including physical activity levels, blood pressure, other measures of adiposity and fat distribution, insulin and fasting glucose, and lipid biomarkers. The studies included in the main comparison did not report on the following important outcomes: physical well-being, overall quality of life, mortality, adverse events, comorbidities, disability, presence of obesity in adulthood, alterations in hunger or satiety, or access to health services. One physical activity intervention versus another physical activity intervention or active control All comparisons involving one type of physical activity versus another type (for example, high-intensity interval training versus moderate-intensity continuous training) or versus an active control group (such as participation in regular school physical activity programmes) were supported by very low-certainty evidence. Thus, the effects of the various types and levels of physical activity on the reported outcomes are uncertain.

Physical activity may improve health outcomes in adolescents with obesity, but the certainty of the evidence is low to very low. Serious methodological limitations, clinical and statistical heterogeneity, as well as small-study effects and imprecise results limited the certainty and interpretability of the current evidence base. Important knowledge gaps remain as none of the included studies enrolled adolescents with disabilities, the studies provided little information on contextual factors, and the amount of evidence hindered the analysis of relevant subgroups. Future high-quality, well-reported studies will likely change the review's conclusions.

The Department of Nutrition and Food Safety at the World Health Organization (WHO) commissioned and provided financial support for this work. WHO acknowledges financial support from the Norwegian Agency for Development Cooperation, the Swedish International Development Cooperation Agency, the Government of the Grand Duchy of Luxembourg, and the Government of Germany to the Department of Nutrition and Food Safety.

The full protocol was registered, and it is publicly available (https://osf.io/2wksa).