Vegetarian Diet

Last Updated: August 29, 2024

A vegetarian diet excludes all red meat, poultry, and seafood but can include eggs and dairy products. There is some promising evidence that a vegetarian diet could help in the prevention and treatment of certain chronic conditions like high blood pressure, type 2 diabetes, and high cholesterol. While there are some concerns regarding nutritional deficiencies, a well-planned vegetarian diet can provide all the required nutrients.

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What is a vegetarian diet?

A vegetarian diet excludes all meat products — including red meat, poultry, and seafood — as well as byproducts of slaughter. Variations of this diet include lacto-ovo, lacto, and ovo vegetarianism; pescatarian and flexitarian diets are sometimes confused with vegetarianism due to their inclusion of certain animal products.

What are the main benefits of a vegetarian diet?

Consuming a vegetarian diet has been associated with lower cholesterol, triglyceride, and apolipoprotein B levels, which potentially reduce the risk of ischemic heart disease and stroke. Additionally, it may be associated with a lower risk of developing type 2 diabetes and can aid in glycemic control, although its effectiveness for diabetes treatment is inconclusive.

Is a vegetarian diet effective for weight loss?

Does a vegetarian diet lower the risk of cancer?

Is a vegetarian diet a good option for athletes?

Does a vegetarian diet provide enough protein?

What are the main drawbacks of a vegetarian diet?

The main drawbacks of a vegetarian diet include potential nutritional deficiencies in micronutrients that are primarily found in animal products, such as zinc, vitamin B12, and iron. Low iron levels are particularly common in premenopausal women, but careful planning and monitoring can help mitigate the increased risk of nutrient deficiencies.

How does a vegetarian diet work?

A vegetarian diet emphasizes the consumption of fruits, vegetables, whole grains, and legumes, which are high in fiber, vitamins, and minerals and low in saturated fats. This dietary approach can lower LDL cholesterol, improve blood sugar levels, aid in weight loss, and enhance cardiovascular health through its antioxidant and anti-inflammatory properties.

What are other names for Vegetarian Diet?
Note that Vegetarian Diet is also known as:
  • lacto-ovo vegetarian (if it includes eggs and dairy products)
  • ovo vegetarian (if it includes only eggs)
  • lacto vegetarians (if it includes only dairy products)
Vegetarian Diet should not be confused with:
  • a vegan diet
  • a whole-food, plant-based diet (This term could be used to describe a vegetarian diet, but it can also refer to other plant-based diets.)

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Update History
2024-08-29 00:30:03

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The vegetarian diet page is new!

All of the following FAQs have been added:

What is a vegetarian diet?: Defining a vegetarian diet is not as simple as it seems, as there is some variation in the literature. Generally, a vegetarian diet excludes meat, meat by-products, poultry, and seafood but may include eggs and dairy products. We describe different types of vegetarian diets and how they differ from vegan diets.

What are the main benefits of a vegetarian diet?: Vegetarian diets can have a positive impact on blood cholesterol levels, cardiovascular disease risk factors, and blood glucose levels for type 2 diabetics.

What are the main drawbacks of a vegetarian diet?: The potential for deficiencies, in particular iron, vitamin B12, and zinc, is discussed, as well as some options to try to avoid these drawbacks.

How does a vegetarian diet work?: Including more fruit, vegetables, whole grains, and legumes in the diet can have positive effects through antioxidants, anti-inflammatory effects, and increased fiber intake.

Is a vegetarian diet effective for weight loss?: In some people, a vegetarian diet might help with weight loss but it is not clear if these effects are long term.

Does a vegetarian diet lower the risk for cancer?: This remains uncertain as studies find conflicting results in various types of cancer.

Is a vegetarian diet good for athletes?: A vegetarian diet can support athletic performance, but a focus on calorie intake, fat intake, and protein intake is important and requires planning.

Does a vegetarian diet provide enough protein?: A well-planned diet can provide enough protein through plant proteins, dairy products, eggs, and in some cases supplements.

Written By

Megan Michaux

Reviewed By

Katie Jantz
References
  1. ^Rocha JP, Laster J, Parag B, Shah NUMultiple Health Benefits and Minimal Risks Associated with Vegetarian Diets.Curr Nutr Rep.(2019 Dec)
  2. ^Pilis W, Stec K, Zych M, Pilis AHealth benefits and risk associated with adopting a vegetarian diet.Rocz Panstw Zakl Hig.(2014)
  3. ^Wozniak H, Larpin C, de Mestral C, Guessous I, Reny JL, Stringhini SVegetarian, pescatarian and flexitarian diets: sociodemographic determinants and association with cardiovascular risk factors in a Swiss urban population.Br J Nutr.(2020 Oct 28)
  4. ^Clarys P, Deliens T, Huybrechts I, Deriemaeker P, Vanaelst B, De Keyzer W, Hebbelinck M, Mullie PComparison of nutritional quality of the vegan, vegetarian, semi-vegetarian, pesco-vegetarian and omnivorous dietNutrients.(2014 Mar 24)
  5. ^Fernandes Dourado K, de Arruda Cámara E Siqueira Campos F, Sakugava Shinohara NKRelation between dietary and circulating lipids in lacto-ovo vegetarians.Nutr Hosp.(2011 Sep-Oct)
  6. ^Dinu M, Abbate R, Gensini GF, Casini A, Sofi FVegetarian, vegan diets and multiple health outcomes: A systematic review with meta-analysis of observational studiesCrit Rev Food Sci Nutr.(2017 Nov 22)
  7. ^Koch CA, Kjeldsen EW, Frikke-Schmidt RVegetarian or vegan diets and blood lipids: a meta-analysis of randomized trials.Eur Heart J.(2023-Jul-21)
  8. ^Wang F, Zheng J, Yang B, Jiang J, Fu Y, Li DEffects of Vegetarian Diets on Blood Lipids: A Systematic Review and Meta-Analysis of Randomized Controlled TrialsJ Am Heart Assoc.(2015 Oct 27)
  9. ^Kai Wei Lee, Hong Chuan Loh, Siew Mooi Ching, Navin Kumar Devaraj, Fan Kee HooEffects of Vegetarian Diets on Blood Pressure Lowering: A Systematic Review with Meta-Analysis and Trial Sequential AnalysisNutrients.(2020 May 29)
  10. ^Yokoyama Y, Nishimura K, Barnard ND, Takegami M, Watanabe M, Sekikawa A, Okamura T, Miyamoto YVegetarian diets and blood pressure: a meta-analysis.JAMA Intern Med.(2014 Apr)
  11. ^Melgar B, Diaz-Arocutipa C, Huerta-Rengifo C, Piscoya A, Barboza JJ, Hernandez AVVegetarian 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 (Lond).(2023-Oct)
  12. ^Yujin Lee, Kyong ParkAdherence to a Vegetarian Diet and Diabetes Risk: A Systematic Review and Meta-Analysis of Observational StudiesNutrients.(2017 Jun 14)
  13. ^Serena Tonstad, Terry Butler, Ru Yan, Gary E FraserType of vegetarian diet, body weight, and prevalence of type 2 diabetesDiabetes Care.(2009 May)
  14. ^Rizzo NS, Sabaté J, Jaceldo-Siegl K, Fraser GEVegetarian dietary patterns are associated with a lower risk of metabolic syndrome: the adventist health study 2.Diabetes Care.(2011 May)
  15. ^Effie Viguiliouk, Cyril Wc Kendall, Hana Kahleová, Dario Rahelić, Jordi Salas-Salvadó, Vivian L Choo, Sonia Blanco Mejia, Sarah E Stewart, Lawrence A Leiter, David Ja Jenkins, John L SievenpiperEffect of Vegetarian Dietary Patterns on Cardiometabolic Risk Factors in Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled TrialsClin Nutr.(2019 Jun)
  16. ^Yoko Yokoyama, Neal D Barnard, Susan M Levin, Mitsuhiro WatanabeVegetarian diets and glycemic control in diabetes: a systematic review and meta-analysisCardiovasc Diagn Ther.(2014 Oct)
  17. ^Pawlak RVegetarian Diets in the Prevention and Management of Diabetes and Its ComplicationsDiabetes Spectr.(2017 May)
  18. ^Kahleova H, Pelikanova TVegetarian Diets in the Prevention and Treatment of Type 2 Diabetes.J Am Coll Nutr.(2015)
  19. ^Olubukola Ajala, Patrick English, Jonathan PinkneySystematic review and meta-analysis of different dietary approaches to the management of type 2 diabetesAm J Clin Nutr.(2013 Mar)
  20. ^Pawlak R, Berger J, Hines IIron Status of Vegetarian Adults: A Review of Literature.Am J Lifestyle Med.(2018 Nov-Dec)
  21. ^Lisa M Haider, Lukas Schwingshackl, Georg Hoffmann, Cem EkmekciogluThe effect of vegetarian diets on iron status in adults: A systematic review and meta-analysisCrit Rev Food Sci Nutr.(2018 May 24)
  22. ^Hunt JRBioavailability of iron, zinc, and other trace minerals from vegetarian dietsAm J Clin Nutr.(2003 Sep)
  23. ^Foster M, Chu A, Petocz P, Samman SEffect of vegetarian diets on zinc status: a systematic review and meta-analysis of studies in humans.J Sci Food Agric.(2013 Aug 15)
  24. ^Foster M, Samman SVegetarian diets across the lifecycle: impact on zinc intake and status.Adv Food Nutr Res.(2015)
  25. ^Pawlak R, Parrott SJ, Raj S, Cullum-Dugan D, Lucus DHow prevalent is vitamin B(12) deficiency among vegetarians?Nutr Rev.(2013 Feb)
  26. ^Niklewicz A, Smith AD, Smith A, Holzer A, Klein A, McCaddon A, Molloy AM, Wolffenbuttel BHR, Nexo E, McNulty H, Refsum H, Gueant JL, Dib MJ, Ward M, Murphy M, Green R, Ahmadi KR, Hannibal L, Warren MJ, Owen PJ, CluB-12The importance of vitamin B(12) for individuals choosing plant-based diets.Eur J Nutr.(2023 Apr)
  27. ^Wang T, Masedunskas A, Willett WC, Fontana LVegetarian and vegan diets: benefits and drawbacks.Eur Heart J.(2023 Sep 21)
  28. ^The Health Benefits of a Vegetarian DietJ Altern Complement Med.(2009-04-23)
  29. ^Joan Sabaté, Michelle WienVegetarian diets and childhood obesity preventionAm J Clin Nutr.(2010 May)
  30. ^E A Spencer, P N Appleby, G K Davey, T J KeyDiet and body mass index in 38000 EPIC-Oxford meat-eaters, fish-eaters, vegetarians and vegansInt J Obes Relat Metab Disord.(2003 Jun)
  31. ^P K Newby, Katherine L Tucker, Alicja WolkRisk of overweight and obesity among semivegetarian, lactovegetarian, and vegan womenAm J Clin Nutr.(2005 Jun)
  32. ^Ru-Yi Huang, Chuan-Chin Huang, Frank B Hu, Jorge E ChavarroVegetarian Diets and Weight Reduction: a Meta-Analysis of Randomized Controlled TrialsJ Gen Intern Med.(2015 Jul 3)
  33. ^Bennett WL, Appel LJVegetarian Diets for Weight Loss: How Strong is the Evidence?J Gen Intern Med.(2016 Jan)
  34. ^Solange Parra-Soto, Danay Ahumada, Fanny Petermann-Rocha, Jirapitcha Boonpoor, Jose Lara Gallegos, Jana Anderson, Linda Sharp, Fiona C Malcomson, Katherine M Livingstone, John C Mathers, Jill P Pell, Frederick K Ho, Carlos Celis-MoralesAssociation of meat, vegetarian, pescatarian and fish-poultry diets with risk of 19 cancer sites and all cancer: findings from the UK Biobank prospective cohort study and meta-analysisBMC Med.(2022 Feb 24)
  35. ^Zhao Y, Zhan J, Wang Y, Wang DThe Relationship Between Plant-Based Diet and Risk of Digestive System Cancers: A Meta-Analysis Based on 3,059,009 Subjects.Front Public Health.(2022)
  36. ^Michael J Orlich, Pramil N Singh, Joan Sabaté, Jing Fan, Lars Sveen, Hannelore Bennett, Synnove F Knutsen, W Lawrence Beeson, Karen Jaceldo-Siegl, Terry L Butler, R Patti Herring, Gary E FraserVegetarian dietary patterns and the risk of colorectal cancersJAMA Intern Med.(2015 May)
  37. ^Tao Huang, Bin Yang, Jusheng Zheng, Guipu Li, Mark L Wahlqvist, Duo LiCardiovascular disease mortality and cancer incidence in vegetarians: a meta-analysis and systematic reviewAnn Nutr Metab.(2012)
  38. ^Bai T, Peng J, Zhu X, Wu CVegetarian diets and the risk of gastrointestinal cancers: a meta-analysis of observational studies.Eur J Gastroenterol Hepatol.(2023-Nov-01)
  39. ^Baroni L, Rizzo G, Galchenko AV, Zavoli M, Serventi L, Battino MHealth Benefits of Vegetarian Diets: An Insight into the Main Topics.Foods.(2024 Jul 29)
  40. ^Godos J, Bella F, Sciacca S, Galvano F, Grosso GVegetarianism and breast, colorectal and prostate cancer risk: an overview and meta-analysis of cohort studies.J Hum Nutr Diet.(2017 Jun)
  41. ^Dunneram Y, Lee JY, Watling CZ, Fraser GE, Miles F, Prabhakaran D, Shridhar K, Kondal D, Mohan V, Ali MK, Narayan KMV, Tandon N, Tong TYN, Chiu THT, Lin MN, Lin CL, Yang HC, Liang YJ, Greenwood DC, Du H, Chen Z, Yu C, Kakkoura MG, Reeves GK, Papier K, Floud S, Sinha R, Liao LM, Loftfield E, Cade JE, Key TJ, Perez-Cornago AMethods and participant characteristics in the Cancer Risk in Vegetarians Consortium: a cross-sectional analysis across 11 prospective studies.BMC Public Health.(2024 Aug 2)
  42. ^Nieman DCPhysical fitness and vegetarian diets: is there a relation?Am J Clin Nutr.(1999 Sep)
  43. ^Barr SI, Rideout CANutritional considerations for vegetarian athletes.Nutrition.(2004 Jul-Aug)
  44. ^Witkoś J, Hartman-Petrycka MThe Female Athlete Triad-the impact of running and type of diet on the regularity of the menstrual cycle assessed for recreational runners.PeerJ.(2022)
  45. ^Hernández-Lougedo J, Maté-Muñoz JL, García-Fernández P, Úbeda-D'Ocasar E, Hervás-Pérez JP, Pedauyé-Rueda BThe Relationship between Vegetarian Diet and Sports Performance: A Systematic Review.Nutrients.(2023 Nov 6)
  46. ^Craddock JC, Probst YC, Peoples GEVegetarian and Omnivorous Nutrition - Comparing Physical PerformanceInt J Sport Nutr Exerc Metab.(2016 Jun)
  47. ^Stuart M Phillips, Stéphanie Chevalier, Heather J LeidyProtein "requirements" beyond the RDA: implications for optimizing healthAppl Physiol Nutr Metab.(2016 May)
  48. ^Jakub G Sobiecki, Paul N Appleby, Kathryn E Bradbury, Timothy J KeyHigh compliance with dietary recommendations in a cohort of meat eaters, fish eaters, vegetarians, and vegans: results from the European Prospective Investigation into Cancer and Nutrition-Oxford studyNutr Res.(2016 May)
  49. ^François Mariotti, Christopher D GardnerDietary Protein and Amino Acids in Vegetarian Diets-A ReviewNutrients.(2019 Nov 4)
Examine Database References
  1. HbA1c - Guest NS, Raj S, Landry MJ, Mangels AR, Pawlak R, Senkus KE, Handu D, Rozga MVegetarian and Vegan Dietary Patterns to Treat Adult Type 2 Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.Adv Nutr.(2024 Oct)
  2. HbA1c - Lv M, Mao J, Wang S, Zhang C, Ma Y, Xu H, Qian C, Guo LEffects of Vegetarian or Vegan Diets on Glycemic and Cardiometabolic Health in Type 2 Diabetes: A Systematic Review and Meta-analysis.Nutr Rev.(2025 Mar 2)