The addition of exercise to a weight loss diet on inflammatory markers: a systematic review and Meta-analysis of controlled clinical trials

Abstract

This systematic review and meta-analysis of controlled clinical trials was performed to evaluate the effects of weight-loss diets plus exercise compared with weight-loss diets alone on inflammatory biomarkers in adults. PubMed, Scopus, EMBASE, Web of Science (ISI), and Google Scholar were searched up to April 2021. Overall effects were derived using a random effects model. The overall quality of evidence was assessed using Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Twenty-nine trials were included in this systematic review and meta-analysis. The meta-analysis showed no significant difference in serum high sensitivity C-reactive protein (hs-CRP) [weighted mean difference (WMD) = −0.004 mg/l, 95% CI: −0.140, 0.132, P = 0.954], interleukin-6 (IL-6) (WMD = −0.039 pg/ml, 95% CI: −0.233 to 0.156, P = 0.696), and tumor necrosis factor-α (TNF-α) (WMD = 0.405 ng/ml, 95% CI: −1.036 to 0.226, P = 0.209) after adding exercise to a weight-loss diet compared with a weight-loss diet alone. Subgroup analysis revealed that exercise plus a weight-loss diet significantly reduced TNF-α in studies greater than 16 weeks in duration (WMD = −0.742 ng/ml, 95% CI: −1.384 to −0.1, P = 0.024). This systematic review and meta-analysis indicate that exercise in addition to a weight-loss diet does not have a significant effect on further reducing inflammatory markers compared to a weight loss diet alone.

Keywords:

• Adults
• aerobic
• CRP
• diet
• exercise
• IL-6
• inflammation
• inflammatory markers
• meta-analysis
• resistance
• systematic review
• TNF- α
• weight-loss

Acknowledgements

We would like to thank the research council of Nutrition and Food Security Research Center for scientific support.

Author’s contributions

ASA, SF, MK, and JSB conceived the study. ASA, ZY, and SS contributed in defining the search strategy. SB, ZY, SS, SHR, SMT, TZ conducted the search, study selection and data extraction. SB and ASA conducted the statistical analyses. SB wrote the first draft of the manuscript. ASA, SF, MK, and JSB critically revised the manuscript. All authors read and approved the final version of the manuscript.

Disclosure statement

None of the authors have any conflicts of interest to report.

Additional information

Funding

The current systematic review and meta-analysis was supported by the Research Council of the Nutrition and Food Security Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.