Effects of dietary and physical activity interventions on metabolic syndrome: A meta-analysis

Purpose: This study identified effects of dietary and physical activity interventions including dietary interventions or physical activity interventions alone or combined dietary-physical activity interventions to improve symptoms in metabolic syndrome including abdominal obesity, high triglycerides, low high density lipoprotein cholesterol, elevated blood pressure, and elevated fasting glucose through meta-analysis. Methods: Articles on metabolic syndrome X published from 1988 to 2013 were searched through electronic databases, Google Scholar, and reference reviews. Methodological quality was assessed by the checklist, SIGN (Scottish Intercollegiate Guidelines Network). Results: In the meta-analysis, there were 9 articles reporting 13 interventions with 736 participants. Using random effect models, the dietary and/or physical activity interventions showed a lower mean difference in waist circumference (- 1.30 cm, 95% CI: - 2.44~ - 0.15, p =.027). The combined dietary-physical activity interventions showed a lower mean difference in waist circumference (- 2.77 cm, 95% CI: - 4.77~ - 0.76, p =.007) and systolic blood pressure (- 5.44 mmHg, 95% CI: - 10.76~ - 0.12, p =.044). Additionally, interventions of over 24 weeks yielded a lower mean difference in waist circumference (- 2.78 cm, 95% CI: - 4.69~ - 0.87, p =.004) and diastolic blood pressure (- 1.93 mmHg, 95% CI: - 3.63~ - 0.22, p =.026). Conclusion: The findings indicate that dietary and/or physical activity interventions for metabolic syndrome reduce central obesity with no adverse effects. This finding provides objective evidences for dietary and physical activity management on metabolic syndrome as an efficient intervention.