The Effect of Diet or Exercise on Visceral Adipose Tissue in Overweight Youth

Abstract

Objective: Excess visceral adipose tissue (VAT) in children with obesity is associated with development of cardiovascular and metabolic disease. This meta-analysis investigated if lifestyle interventions can reduce VAT in overweight and obese youth. Methods: Pubmed, Cochrane and PEDro were searched for clinical trials that objectively assessed VAT and included study arms with supervised diet, exercise or a combination. If there was a „no-therapy‟ control group, the data of the control group and the intervention groups were used to meta-analyze the data. In all other cases the pre-intervention and the post-intervention data were used to meta-analyze. Effect sizes were calculated as standardized mean differences or changes of VAT and expressed as Hedges‟g. Results: The overall weighted mean effect size on VAT of all included interventions was - 0.69 [95%CI = -0.90 to -0.48] (p <0.001). Subgroup analysis showed that the overall weighted mean effect size of diet-only interventions on VAT was 0.23 [95%CI = -0.22 to 0.68] (p =0.311). Interventions that combined diet and exercise showed a pooled effect size on VAT of - 0.55 [95%CI = -0.75 to -0.39] (p <0.001). The pooled effect size of exercise-only interventions on VAT was -0.85 [95%CI = -1.20 to -0.57] (p <0.001). Conclusions: Supervised exercise-only or combined diet and exercise interventions can reduce VAT in overweight and obese children and adolescents. The strongest effect was found in exercise-only groups. However, high quality RCT‟s describing the effect of supervised dietary interventions on VAT in children are lacking.