Abstract 9687: Exercise Improves BMI Z-Score in Overweight and Obese Children and Adolescents: A Systematic Review With Meta-Analysis
Introduction: Previous studies have reached conflicting conclusions regarding the effects of exercise on adiposity in overweight and obese children and adolescents.
Hypothesis: Exercise (aerobic, strength, or both) improves body mass index (BMI) z-score in overweight and obese children and adolescents.
Methods: Studies meeting the following criteria were included: (1) randomized controlled trials, (2) exercise ≤ 4 weeks, (3) overweight/obese children and adolescents 2-18 years of age, (4) studies published in any language from 1990-2012, (5) BMI z-score data available. Studies were derived from 7 electronic databases, cross-referencing and expert review. Two investigators independently selected and abstracted all data. Exercise minus control group changes were calculated from each study and inverse variance weighted. Results were pooled using a random-effects model with non-overlapping 95% confidence intervals (CI) considered statistically significant. Q and I2 statistics were used to assess heterogeneity while funnel plots and Egger’s regression test were used to assess small-study effects. Influence and cumulative meta-analysis were performed as well as moderator and meta-regression analyses.
Results: Of 4,999 citations reviewed, 835 children and adolescents (456 exercise, 379 control) from 10 studies were included. On average, exercise took place 4 x week for 43 minutes per session over 16 weeks. A statistically significant reduction of approximately 3% was found for BMI z-score along with moderate heterogeneity (mean, -0.06, 95% CI, -0.09 to -0.03; Q = 24.9, p = 0.01; I2= 59.8%). No small-study effects were observed and results remained statistically significant when each study was deleted from the model once. Cumulative meta-analysis revealed that results have been statistically significant since 2009. No moderator or regression analyses were statistically significant. The number needed-to-treat was 9 with an estimated 1.4 million obese US children and adolescents and 12.2 million overweight and obese children and adolescents worldwide potentially improving their BMI z-score by exercising.
Conclusions: Exercise improves BMI z-score in overweight and obese children and adolescents.
Author Disclosures: G.A. Kelley: None. K.S. Kelley: None. R.R. Pate: None.
This research has received full or partial funding support from the American Heart Association.
- © 2014 by American Heart Association, Inc.