Adherence to Vegetarian Diet and Weight Loss: A Meta-Analysis Adherence to Vegetarian Diet and Weight Loss: A Meta-Analysis
Main Article Content
Keywords
Vegetarian diet, Weight loss, Meta-analysis
Abstract
Background
Veganism and vegetarianism, which are becoming popular worldwide, are not only a diet but a lifestyle, a philosophy of life, and an ethical approach. A vegetarian diet is thought to be the solution to the increasing food requirements of the growing population. In this meta-analysis, we evaluated the correlation between a vegetarian diet and weight loss.
Methods
For the meta-analysis, PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed. We conducted a comprehensive review of the literature published in PubMed, Science Direct, and ResearchGate databases. Only randomized controlled trials and cohort studies published after 2007 were included in the meta-analysis if they reported the results on weight loss and contained appropriate statistical analysis data.
Results
The meta-analysis included 11 studies comprising of 934 participants, of which 10 were randomized controlled trials, and 1 was a cohort study. Applying the random effects model, it was concluded that compliance with the various types of vegetarian diets had a positive effect on weight loss. The effect size of the relation between vegetarian diet and weight loss was 0.954. It is between the lower limit (0.393) and the upper limit (1.515) values for the effect sizes of the relevant studies in the 95% confidence interval. There was no publication bias as the circles (representing each study) shown in the Funnel plot graph were spread symmetrically around the vertical line in the middle.
Conclusions
The vegetarian diets (vegan and lacto-ovo vegetarian diets) had beneficial effects on weight loss. One possible reason responsible for weight loss could be the varied nutritional composition, for example, high fiber and low protein diet. However, further interventional studies with vegetarian diets are warranted to investigate their long-term effects and clinical implications on weight loss.
References
2. Son TGY. Biyoetik çerçevesinde vegan ve vejetaryenlik. Sosyal Bilimleri Enstitüsü, Sosyal Çevre Bilimleri Anabilim Dalı. Doktora tezi, Ankara: Ankara Üniversitesi, 2016.
3. Ongan D, Ersoy G. Vejetaryen sporcular: Özel gereksinimleri. Uluslararası İnsan Bilimleri Dergisi 2012; 9(1): 261-270.
4. Le L, Sabate J. Beyond meatless, the health effects of vegan diets: findings from the adventist cohorts. Nutrients 2014;6 (6): 2131-2147.
5. Appleby PN, Thorogood M, Mann JI, Key TJ. The oxford vegetarian study: an overview1–3. Am J Clin Nutr 1999;70(3): 525–31.
6. Spencer EA, Appleby PN, Davey GK, Key TJ. Diet and body mass index in 38000 EPIC-Oxford meat-eaters, fish-eaters, vegetarians and vegans. Int J Obes 2003; 27: 728–34.
7. American Society for Nutrition. Vegetarian and Vegan Nutrition Report. 2009. Available at: https://www.vrg.org/nutrition/2009_ADA_position_paper.pdf
8. Huang RY, Huang CC, Hu FB, Chavarro JE. Vegetarian diets and weight reduction: a meta-analysis of randomized controlled trials. J Gen Intern Med 2015; 31(1):109–116.
9. Cohen L, Manion L, Morrison K. Research methods in education, 8th ed.; Routledge :New York, 2018.
10. Borenstein M, Hedges LV, Higgins JPT, Rothstein HR. Introduction to meta-analysis, John Wiley & Sons, Ltd.: Chichester,2009.
11. Hedges LV, OIkin I.Statistical methods for meta-analysis, Academic Press: New York, 1985.
12. Shelby LB, Vaske JJ. Understanding meta-analysis: A review of the methodological literatüre. Leisure Sciences 2008;30:96-110.
13. Cooper H, Hedges LV, Valentine JC. The Handbook of Research Synthesis and Meta-Analysis, Russel Sage Foundation: New York, 2009.
14. Rothstein HR, Sutton AJ, Borenstein M. Publication bias in meta-analysis. Publication bias in meta-analysis: Prevention, assessment and adjustments 2005;1-7.
15. Barnard N, Levin SM, Gloede L, Flores R. Turning the Waiting Room into a Classroom: Weekly Classes Using a Vegan or a Portion-Controlled Eating Plan Improve Diabetes Control in a Randomized Translational Study. J Acad Nutr Diet 2018;118(6):1072-1079.
16. Burke LE, Hudson AG, Warziski MT, et al. Effects of a vegetarian diet and treatment preference on biochemical and dietary variables in overweight and obese adults: a randomized clinical trial. Am J Clin Nutr; 86(3):588 –596.
17. Djekic D, Shi L, Brolin H, et al. Effects of a Vegetarian Diet on Cardiometabolic Risk Factors, Gut Microbiota, and Plasma Metabolome in Subjects With Ischemic Heart Disease: A Randomized, Crossover Study. J Am Heart Assoc 2020;9:e016518
18. Ferdowsian H, Barnard ND, Hoover VJ, et al. A Multicomponent Intervention Reduces Body Weight and Cardiovascular Risk at a GEICO Corporate Site. Am J Health Promot 2010; 24(6).
19. Kahleova H, Matoulek M, Malinska H, et al. Vegetarian diet improves insulin resistance and oxidative stress markers more than conventional diet in subjects with Type 2 diabetes. Diabetic Med 2010; 549-559.
20. Kahleova H, Tura A, Hill M, Holubkov R, Barnard ND. A Plant-Based Dietary Intervention Improves Beta-Cell Function and Insulin Resistance in Overweight Adults: A 16-Week Randomized Clinical Trial. Nutrients 2018; 10:189.
21. Lee YM, Kim SA, Lee IK, et al. Effect of a Brown Rice Based Vegan Diet and Conventional Diabetic Diet on Glycemic Control of Patients with Type 2 Diabetes: A 12-Week Randomized Clinical Trial. PLoS ONE 2016; 11 (6): e0155918.
22. Sofi F, Dinu M, Pagliai G, et al. Low-Calorie Vegetarian Versus Mediterranean Diets for Reducing Body Weight and Improving Cardiovascular Risk Profile CARDIVEG Study (Cardiovascular Prevention With Vegetarian Diet). Am Heart J 2018;137.
23. Shah B, Newman JD, Woolf K, et al. Anti-Inflammatory Effects of a Vegan Diet Versus the American Heart Association–Recommended Diet in Coronary Artery Disease Trial. J Am Heart Assoc 2018;7:e011367.
24. Sushama D., Brooks M.M., Evans RW, et al. Weight Loss Is More Important Than the Diet Type in Improving Adiponectin Levels Among Overweight/Obese Adults. J Am Coll Nutr 2013;32:4, 264-271.
25. Wright N, Wilson L, Smith M, et al. The BROAD study: A randomised controlled trial using a whole food plant-based diet in the community for obesity, ischaemic heart disease or diabetes. Nutr Diabetes 2017; 7:e256.
26. Huang RY, Huang CC, Hu FB, Chavarro JE. Vegetarian Diets and Weight Reduction: a Meta-Analysis of Randomized Controlled Trials. J Gen Intern Med 2015;31(1):109–16.
.
27. Mishra S, Xu J, Agarwal U. 26. Mishra S, Xu J, Agarwal U, Gonzales J, Levin S, Barnard ND, et al. A multicenter randomized controlled trial of a plant-based nutrition program to reduce body weight and cardiovascular risk in the corporate setting: the GEICO study. European Journal of Clinical Nutrition 2013; 67:718–724
28. Barnard ND, Cohen J, Jenkins DJ, et al.A low-fat vegan diet and a conventional diabetes diet in the treatment of type 2 diabetes: a randomized, controlled, 74-wk clinical trial. Am J Clin Nutr 2009;89(5):1588S–1596S.
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