The Effect of Exercise Training on Liver Fat Accumulation in Children and Adolescents in Individuals with Overweight and Obesity: A Systematic Review and Meta-Analysis

The prevalence of obesity in children and adolescents is associated with the accumulation of liver fat. Therefore, the purpose of this meta-analysis is to investigate the effect of exercise training on liver fat accumulation and insulin resistance in children and adolescents with overweight and obesity.

A comprehensive search was conducted in PubMed, Web of Science, Google Scholar, Magiran, and NoorMags databases from the inception to January 21, 2023. The inclusion criteria for the present meta-analysis included 1) children and adolescents, 2) exercise training, 3) overweight and obesity, 4) studies with a control group or with values measured in the pre-test stage and 4) liver fat as the main variable. To calculate the effect size, standardized mean differences (SMD), weighted mean differences (WMD) and 95% confidence intervals (CIs) were calculated using the random effect model.

A total, nine studies with eighteen exercise interventions and including 621 children and adolescent were included in the meta-analysis. Exercise result in a decrease in liver fat with a large effect size [SMD: -0.85 (CI: -1.26 to -0.43), P = 0.001], insulin [WMD: -1.32 µU/ml (CI: -2.35 to -0.30), P = 0.01] and insulin resistance [WMD: -0.61 (CI: -1.06 to -0.17), P = 0.007]. While the reduction of glucose was not statistically significant [WMD: -0.52 mg/dl (CI: -1.47 to 0.40), P = 0.26].

Exercise training results in the reduction of liver fat accumulation and improvement of insulin resistance in children and adolescents with overweight and obesity, which is recommended as a main strategy to reduce liver fat and improve metabolism.