Vegetarian diets on anthropometric, metabolic and blood pressure outcomes in people with overweight and obesity: a systematic review and meta

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Jul 07, 2023

Vegetarian diets on anthropometric, metabolic and blood pressure outcomes in people with overweight and obesity: a systematic review and meta

Clinical research International Journal of Obesity (2023)Cite this article 57 Accesses 10 Altmetric Metrics details It is unknown whether vegetarian diets (VDs) may improve outcomes in people with

Clinical research

International Journal of Obesity (2023)Cite this article

57 Accesses

10 Altmetric

Metrics details

It is unknown whether vegetarian diets (VDs) may improve outcomes in people with overweight and obesity.

To systematically assess the effects of VDs vs. omnivore diets on anthropometric, metabolic, and blood pressure outcomes in people with overweight and obesity.

We searched for randomized controlled trials (RCTs) in EMBASE, PubMed, Web of Science, and Scopus until February 2, 2022. Primary outcomes were anthropometric risk factors (weight, body mass index [BMI], waist circumference [WC], hip circumference [HC], and body fat percentage). Secondary outcomes were metabolic risk factors (fasting serum glucose, HbA1c, insulin levels) and blood pressure (systolic blood pressure [SBP], diastolic blood pressure [DBP]). Random-effects meta-analyses were performed and effects were expressed as mean difference (MD) and their 95% confidence intervals (CI). The quality of evidence was assessed using GRADE methods.

Nine RCTs (n = 1628) were included. VDs decreased weight (MD −3.60 kg, 95%CI −4.75 to −2.46) and glucose (MD −10.64 mg/dL, 95%CI −15.77 to −5.51), but did not decrease WC (MD −3.00 cm, 95%CI −6.20 to 0.20), BMI (MD −0.87 kg/m2, 95%CI −1.80 to 0.06), or HC (MD: −0.86 cm, 95%CI −3.46 to 1.74). VDs did not decrease HbA1c (MD −0.40%, 95%CI −0.89 to 0.10), insulin (MD −3.83 mU/L, 95%CI −8.06 to 0.40), SBP (MD −0.25 mmHg, 95%CI −2.58 to 2.07), or DBP (MD −1.57 mmHg, 95%CI −3.93 to 0.78). Subgroup analyses by type of VD (four RCTs evaluated lacto-ovo-vegetarian diets and five RCTs vegan diets) showed similar results to the main analyses. QoE was very low for most of the outcomes.

In comparison to an omnivorous diet, VDs may reduce weight and glucose, but not blood pressure or other metabolic or anthropometric outcomes. However, the QoE was mostly very low. Larger RCTs are still needed to evaluate the effects of VD on anthropometric, metabolic factors, and blood pressure in people with overweight and obesity.

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Drozdz D, Alvarez-Pitti J, Wójcik M, Borghi C, Gabbianelli R, Mazur A, et al. Obesity and cardiometabolic risk factors: from childhood to adulthood. Nutrients. 2021;13:1–20.

Article Google Scholar

De Lorenzo A, Gratteri S, Gualtieri P, Cammarano A, Bertucci P, Di Renzo L. Why primary obesity is a disease? J Transl Med. 2019;17:1–13.

Article Google Scholar

Gasmi A, Mujawdiya PK, Noor S, Piscopo S, Menzel A. Lifestyle genetics-based reports in the treatment of obesity. Arch Razi Inst. 2021;76:707–19.

CAS PubMed PubMed Central Google Scholar

Arkadianos I, Valdes AM, Marinos E, Florou A, Gill RD, Grimaldi KA. Improved weight management using genetic information to personalize a calorie controlled diet. Nutr J. 2007;6:1–8.

Article Google Scholar

World Health Organization. Obesity and Overweight. Version current 9 June 2021. Internet: https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight. Accessed 10 June 2022.

Pan American Health Organization. Obesity Prevention. Internet: https://www.paho.org/en/topics/obesity-prevention. Accessed 10 June 2022.

World Health Organization. Obesity data and statistics. Version current June 2022, https://www.who.int/europe/publications/i/item/9789289057738. Accessed 10 June 2022.

La Sala L, Pontiroli AE. Prevention of diabetes and cardiovascular disease in obesity. Int J Mol Sci. 2020;21:1–17.

Google Scholar

Jastreboff AM, Kotz CM, Kahan S, Kelly AS, Heymsfield SB. Obesity as a disease: the obesity society 2018 position statement. Obesity. 2019;27:7–9.

Article PubMed Google Scholar

Silveira EA, Kliemann N, Noll M, Sarrafzadegan N, de Oliveira C Visceral obesity and incident cancer and cardiovascular disease: An integrative review of the epidemiological evidence. Obes Rev. 2021; https://doi.org/10.1111/obr.13088

Lin X, Li H. Obesity: epidemiology, pathophysiology, and therapeutics. Front Endocrinol. 2021;12:1–9.

Article Google Scholar

Mohammed MS, Sendra S, Lloret J, Bosch I. Systems and WBANs for controlling obesity. J Healthc Eng. 2018;2018:1–21.

Article Google Scholar

Fraser GE. Vegetarian diets: what do we know of their effects on common chronic diseases? Am J Clin Nutr. 2009;89:1–6.

Article Google Scholar

Position of the American dietetic association and the dietitians of Canada vegetarian diets. J Am Diet Assoc 2003; 103:748–65

Turner-McGrievy GM, Barnard ND, Scialli AR. A two-year randomized weight loss trial comparing a vegan diet to a more moderate low-fat diet. Obesity. 2007;15:2276–81.

Article PubMed Google Scholar

Sacks FM, Bray GA, Carey VJ, Smith SR, Ryan DH, Anton SD, et al. Comparison of weight-loss diets with different compositions of fat, protein, and carbohydrates. N Engl J Med. 2009;360:859–73.

Article CAS PubMed PubMed Central Google Scholar

Garvey WT, Mechanick JI, Brett EM, Garber AJ, Hurley DL, Jastreboff AM, et al. Reviewers of the AACE/ACE obesity clinical practice guidelines. American Association of Clinical Endocrinologists and American College of Endocrinology Comprehensive Clinical Practice Guidelines For Medical Care of Patients With Obesity. Endocr Pract. 2016;22:1–203.

Article PubMed Google Scholar

Page MJ, McKenzie JE, Bossuyt PM, Boutron I, Hoffmann TC, Mulrow CD, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ. 2021;372:1–9.

Google Scholar

Sterne JAC, Savović J, Page MJ, Elbers RG, Blencowe NS, Boutron I, et al. RoB 2: a revised tool for assessing risk of bias in randomised trials. BMJ. 2019;366:1–8.

Google Scholar

Balshem H, Helfand M, Schünemann HJ, Oxman AD, Kunz R, Brozek J, et al. GRADE guidelines: 3. Rating the quality of evidence. J Clin Epidemiol. 2011;64:401–6.

Article PubMed Google Scholar

Doi SA, Barendregt JJ, Khan S, Thalib L, Williams GM. Advances in the meta-analysis of heterogeneous clinical trials I: the inverse variance heterogeneity model. Contemp Clin Trials. 2015;45:130–8.

Article PubMed Google Scholar

Egger M, Davey Smith G, Schneider M, Minder C. Bias in meta-analysis detected by a simple, graphical test. BMJ. 1997;315:629–34.

Article CAS PubMed PubMed Central Google Scholar

Barnard ND, Scialli AR, Turner-McGrievy G, Lanou AJ, Glass J. The effects of a low-fat, plant-based dietary intervention on body weight, metabolism, and insulin sensitivity. Am J Med. 2005;118:991–7.

Article CAS PubMed Google Scholar

Barnard ND, Cohen J, Jenkins DJ, Turner-McGrievy G, Gloede L, Jaster B, et al. A low-fat vegan diet improves glycemic control and cardiovascular risk factors in a randomized clinical trial in individuals with type 2 diabetes. Diabetes Care. 2006;29:1777–83.

Article CAS PubMed Google Scholar

Burke LE, Styn MA, Steenkiste AR, Music E, Warziski M, Choo J. A randomized clinical trial testing treatment preference and two dietary options in behavioral weight management: preliminary results of the impact of diet at 6 months–PREFER study. Obesity (Silver Spring). 2006;14:2007–17.

Article CAS PubMed Google Scholar

Kahleova H, Matoulek M, Malinska H, Oliyarnik O, Kazdova L, Neskudla T, et al. Vegetarian diet improves insulin resistance and oxidative stress markers more than conventional diet in subjects with Type 2 diabetes. Diabet Med. 2011;28:549–59.

Article CAS PubMed PubMed Central Google Scholar

Kahleova H, Klementova M, Herynek V, Skoch A, Herynek S, Hill M, et al. The effect of a vegetarian vs conventional hypocaloric diabetic diet on thigh adipose tissue distribution in subjects with Type 2 diabetes: a randomized study. J Am Coll Nutr. 2017;36:364–9.

Article CAS PubMed Google Scholar

Kahleova H, Petersen KF, Shulman GI, Alwarith J, Rembert E, Tura A, et al. Effect of a low-fat vegan diet on body weight, insulin sensitivity, postprandial metabolism, and intramyocellular and hepatocellular lipid levels in overweight adults: a randomized clinical trial. JAMA Netw Open. 2020;3:1–20.

Article Google Scholar

Karlsson J, Hallgren P, Kral J, Lindroos AK, Sjöström L, Sullivan M. Predictors and effects of long-term dieting on mental well-being and weight loss in obese women. Appetite. 1994;23:15–26.

Article CAS PubMed Google Scholar

Mishra S, Xu J, Agarwal U, Gonzales J, Levin S, Barnard ND. 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. Eur J Clin Nutr. 2013;67:718–24.

Article CAS PubMed PubMed Central Google Scholar

Wright N, Wilson L, Smith M, Duncan B, McHugh P. 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;7:1–10.

Article Google Scholar

Najjar RS, Feresin RG. Plant-based diets in the reduction of body fat: physiological effects and biochemical insights. Nutrients. 2019;11:1–19.

Article Google Scholar

Rolls BJ. The relationship between dietary energy density and energy intake. Physiol Behav. 2009;97:609–15.

Article CAS PubMed PubMed Central Google Scholar

De Oliveira MC, Sichieri R, Venturim, Mozzer R. A low-energy-dense diet adding fruit reduces weight and energy intake in women. Appetite. 2008;51:291–5.

Article PubMed Google Scholar

Flood-Obbagy JE, Rolls BJ. The effect of fruit in different forms on energy intake and satiety at a meal. Appetite. 2009;52:416–22.

Article PubMed Google Scholar

Tseng CH, Wu CY. The gut microbiome in obesity. J Formos Med Assoc. 2019;118:S3–S9. Suppl 1

Article PubMed Google Scholar

Rajaram S, Sabaté J. Nuts, body weight and insulin resistance. Br J Nutr. 2006;96:S79–86. Suppl 2Erratum in: Br J Nutr. 2008; 99:447-8

Article CAS PubMed Google Scholar

Yumuk V, Tsigos C, Fried M, Schindler K, Busetto L, Micic D, et al. Obesity management task force of the european association for the study of obesity. european guidelines for obesity management in adults. Obes Facts. 2015;8:402–24.

Article PubMed PubMed Central Google Scholar

Acharya SD, Elci OU, Sereika SM, Music E, Styn MA, Turk MW, et al. Adherence to a behavioral weight loss treatment program enhances weight loss and improvements in biomarkers. Patient Prefer Adherence. 2009;3:51–60. 1

Google Scholar

UK National Institute for Health and Care Excellence (NICE), National Clinical Guideline Centre. Obesity: identification, assessment and management of overweight and obesity in children, young people and adults. London: UK partial update of CG43. 2014

Picasso MC, Lo-Tayraco JA, Ramos-Villanueva JM, Pasupuleti V, Hernandez AV. Effect of vegetarian diets on the presentation of metabolic syndrome or its components: a systematic review and meta-analysis. Clin Nutr. 2019;38:1117–32.

Article PubMed Google Scholar

Remde A, DeTurk SN, Almardini A, Steiner L, Wojda T. Plant-predominant eating patterns - how effective are they for treating obesity and related cardiometabolic health outcomes? - a systematic review. Nutr Rev. 2022;80:1094–104.

Article PubMed Google Scholar

Barnard ND, Levin SM, Yokoyama Y. A systematic review and meta-analysis of changes in body weight in clinical trials of vegetarian diets. J Acad Nutr Diet. 2015;115:954–69.

Article PubMed Google Scholar

Tran E, Dale HF, Jensen C, Lied GA. Effects of plant-based diets on weight status: a systematic review. Diabetes Metab Syndr Obes. 2020;13:3433–48.

Article CAS PubMed PubMed Central Google Scholar

Huang RY, Huang CC, Hu FB, Chavarro JE. Vegetarian diets and weight reduction: a meta-analysis of randomized controlled trials. J Gen Intern Med. 2016;31:109–16.

Article PubMed Google Scholar

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Unidad de Revisiones Sistemáticas y Meta-análisis (URSIGET), Vicerrectorado de Investigación, Universidad San Ignacio de Loyola, Lima, Peru

Beatriz Melgar, Carlos Diaz-Arocutipa, Alejandro Piscoya, Joshuan J. Barboza & Adrian V. Hernandez

Tau Relaped Group, Trujillo, Peru

Claudia Huerta-Rengifo & Joshuan J. Barboza

Facultad de Medicina, Universidad Privada Antenor Orrego, Trujillo, Peru

Claudia Huerta-Rengifo

Hospital Guillermo Kaelin de la Fuente, Lima, Peru

Alejandro Piscoya

Health Outcomes, Policy, and Evidence Synthesis (HOPES) Group, University of Connecticut School of Pharmacy, Storrs, CT, USA

Adrian V. Hernandez

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BM, AP, and AVH: designed research. BM, CD-A, CR-H, and AVH: conducted research. CD-A, AP, and AVH provided essential materials. BM, CD-A, CR-H, and AVH: analyzed data or performed statistical analysis. BM, CD-A, CR-H, AP, JJB, and AVH: wrote paper. AVH had primary responsibility for final content.

Correspondence to Beatriz Melgar.

The authors declare no competing interests.

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Melgar, B., Diaz-Arocutipa, C., Huerta-Rengifo, C. et al. Vegetarian diets on anthropometric, metabolic and blood pressure outcomes in people with overweight and obesity: a systematic review and meta-analysis of randomized controlled trials. Int J Obes (2023). https://doi.org/10.1038/s41366-023-01357-7

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Received: 31 December 2022

Revised: 01 July 2023

Accepted: 18 July 2023

Published: 01 August 2023

DOI: https://doi.org/10.1038/s41366-023-01357-7

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