Article Text
Abstract
Objective To determine and compare the dose–response effects of exercise and caloric restriction on visceral adipose tissue in overweight and obese adults, while controlling for the weekly energy deficit induced by the interventions.
Methods PubMed, Embase, CINAHL and Web of Science were searched for randomised controlled trials comparing exercise or caloric restriction against eucaloric controls in overweight or obese adults. The primary outcome was the change in visceral fat measured by CT or MRI. Meta-analyses and meta-regressions were performed to determine the overall effect size (ES) and the dose–dependent relationship of exercise and caloric restriction on visceral fat. Heterogeneity, risk of bias and the certainty of evidence were also assessed.
Results Forty randomised controlled trials involving 2190 participants were included. Overall, exercise (ES −0.28 (−0.37 to −0.19); p<0.001; I2=25%) and caloric restriction (ES −0.53 (−0.71 to −0.35); p<0.001; I2=33%) reduced visceral fat compared with the controls. Exercise demonstrated a dose–response effect of −0.15 ((−0.23 to −0.07); p<0.001) per 1000 calories deficit per week, whereas the effect of caloric restriction was not dose-dependent (ES 0.03 (−0.12 to 0.18); p=0.64). Most of the studies showed a moderate risk of bias.
Conclusions These findings support the dose–dependent effects of exercise to reduce visceral fat in overweight and obese adults. Caloric restriction did not demonstrate a dose–response relationship, although this may be attributed to the smaller number of studies available for analysis, compared with exercise studies.
PROSPERO registration number CRD42020210096.
- Exercise
Data availability statement
Data available upon request.
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Data availability statement
Data available upon request.
Supplementary materials
Supplementary Data
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Supplementary Data
This web only file has been produced by the BMJ Publishing Group from an electronic file supplied by the author(s) and has not been edited for content.
Footnotes
Correction notice This article has been corrected since it published Online First. The article type has been changed to systematic review.
Contributors FR accepts full responsibility for the work and/or the conduct of the study, had access to the data, and controlled the decision to publish. FR, CL, AY, WL and PS accessed and verified the data in this study. FR, CL, AY and WL conducted the database search and data extraction. FR, CL, AY, WL and DY conducted the data analyses. All authors interpreted the data, wrote and edited the manuscript.
Funding This study was supported by General Research Fund of Research Grants Council (RGC), Hong Kong University Grants Committee (project number: 17103818, 17105920 and 17110722) and Seed Fund for Basic Research of the University of Hong Kong. Publication made possible in part by support from the HKU Libraries Open Access Author Fund sponsored by the HKU Libraries
Competing interests None declared.
Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.
Provenance and peer review Not commissioned; externally peer reviewed.
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