Vegetarian Diet

What Is the Vegetarian Diet?

  • The vegetarian diet involves avoiding eating meat, poultry, and fish. Vegetarians still consume other animal byproducts including eggs, cheese, and dairy. While a well-rounded and well-planned vegetarian diet may have health benefits, this diet could also pose health risks including nutritional deficiencies, especially important nutrients for children on the spectrum if not followed correctly.

  • There are variations of the vegetarian diet that exclude other animal byproducts. You may hear about the “lacto-ovo-vegetarian diet”, but it is the same thing as a vegetarian diet. Other variations of the vegetarian diet include:

    • Lacto-vegetarian diet: allows dairy products but eliminates eggs along with meat, poultry, and fish. 

    • Ovo-vegetarian diet: allows egg products but eliminates dairy along with meat, poultry, and fish. 

    • Flexitarian diet: a “mostly” vegetarian diet but occasionally incorporates meat, poultry, and fish

    • Pescatarian diet: allows fish (and sometimes eggs & dairy) but eliminates meat and poultry.

    • Vegan diet: eliminates all animal products including meat, poultry, fish, eggs, dairy, and other animal-derived products (like honey)

  • Someone may choose to become vegetarian for many reasons, including religious, ethical, or environmental reasons.

 
 

Potential Health Benefits of a Vegetarian Diet

  • Many people will also choose to become vegetarian for their health [4].

  • While studies do show that following a vegetarian diet can have health benefits such as weight loss, reduced risk of heart disease, and improvement in the gut microbiome [1-3]. It’s important to understand that these benefits come from a well-rounded, plant-focused diet. 

  • One research study showed that in children, vegan diets were associated with a healthier cardiovascular risk profile but also increased risk of nutritional deficiencies, bone mineral content, and height. While vegetarians showed less pronounced nutritional deficiencies, they also had a less favorable cardiometabolic risk profile. [5]

  • Simply eliminating meat or other animal products but continuing to eat highly processed foods as a majority of your diet or exceeding your daily calorie needs with any food will not produce these health benefits.

Potential Health Risks of a Vegetarian Diet

  • A vegetarian diet may put you at risk for nutritional deficiencies if not well-rounded or planned out. Many of these nutrients are especially important for a child on the spectrum, including vitamin B12, omega-3 fatty acids, iron, zinc, vitamin D, and iodine. [4, 6] 

  • If your child is already a picky eater, following an even more restrictive diet could further limit the nutrients your child receives from their diet. We recommend expanding your child’s diet before restricting (for example, successfully introducing vegetarian protein foods before removing the animal-based protein they currently eat). 

  • There is a concern that consuming too much fiber can limit bioavailability/absorption of nutrients in the diet, which is a possibility if eating a plant-based diet. 

  • For these reasons, if following a vegetarian diet (especially a vegan diet), it’s strongly recommended that you do so with the guidance of medical and dietetic supervision and utilize the correct dietary supplementation to fill any nutritional gaps to avoid malnutrition or nutritional deficiencies. A vegetarian diet must be well-planned with special attention to potential nutrient deficiencies.

 
 

Recommended Foods

Foods to Avoid

Lifestyle Changes

  • Vegetarians following this diet for religious, ethical, or environmental reasons may also choose to alter their lifestyle and avoid buying personal or cosmetic products using animal-based products, like leather.

  • Because the vegetarian diet avoids meat that is highly concentrated with nutrients that children on the spectrum need to support brain development (vitamin B12, omega fatty acids, protein, etc), nutritional supplements are recommended.

Helpful Resources

Recommended Supplements

  • Following a vegetarian diet may put you at risk for certain nutrient deficiencies including:

    • Vitamin B12

    • Protein

    • Omega-3 fatty acids

    • Zinc

    • Iron

    • Selenium

    • Vitamin D

    • Calcium

    • Iodine

  • If your child follows a vegetarian diet (even if unintentional due to picky eating) consider a well-rounded multivitamin at the minimum.

DISCLAIMER: Before starting any supplement or medication, always consult with your healthcare provider to ensure it is a good fit for your child. Dosage can vary based on age, weight, gender, and current diet.

The Vegetarian Diet & Autism in the Research

Note: There are no research studies on the vegetarian diet and autism, in particular.


The Bottom Line

While there are reported health benefits for children who follow a well-planned plant-based diet, it may also put them at risk for nutritional deficiencies. The nutrients at risk of deficiency are especially important for kids on the autism spectrum including vitamin B12, omega-3 fatty acids, zinc, iron, and vitamin D. Given that children on the spectrum are more likely to be selective eaters, further restricting the diet to a vegetarian diet is likely more risky than beneficial.


  • [1] Sofi F, Dinu M, Pagliai G, Cesari F, Gori AM, Sereni A, Becatti M, Fiorillo C, Marcucci R, Casini A. Low-Calorie Vegetarian Versus Mediterranean Diets for Reducing Body Weight and Improving Cardiovascular Risk Profile: CARDIVEG Study (Cardiovascular Prevention With Vegetarian Diet). Circulation. 2018 Mar 13;137(11):1103-1113. doi: 10.1161/CIRCULATIONAHA.117.030088. Epub 2018 Feb 26. PMID: 29483085.

    [2] ​​Kahleova H, Levin S, Barnard ND. Vegetarian Dietary Patterns and Cardiovascular Disease. Prog Cardiovasc Dis. 2018 May-Jun;61(1):54-61. doi: 10.1016/j.pcad.2018.05.002. Epub 2018 May 22. PMID: 29800598.

    [3] Djekic D, Shi L, Brolin H, Carlsson F, Särnqvist C, Savolainen O, Cao Y, Bäckhed F, Tremaroli V, Landberg R, Frøbert O. 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 Sep 15;9(18):e016518. doi: 10.1161/JAHA.120.016518. Epub 2020 Sep 6. PMID: 32893710; PMCID: PMC7726986.

    [4] Kiely ME. Risks and benefits of vegan and vegetarian diets in children. Proc Nutr Soc. 2021 May;80(2):159-164. doi: 10.1017/S002966512100001X. Epub 2021 Jan 28. PMID: 33504371.

    [5] Desmond MA, Sobiecki JG, Jaworski M, Płudowski P, Antoniewicz J, Shirley MK, Eaton S, Książyk J, Cortina-Borja M, De Stavola B, Fewtrell M, Wells JCK. Growth, body composition, and cardiovascular and nutritional risk of 5- to 10-y-old children consuming vegetarian, vegan, or omnivore diets. Am J Clin Nutr. 2021 Jun 1;113(6):1565-1577. doi: 10.1093/ajcn/nqaa445. PMID: 33740036; PMCID: PMC8176147.

    [6] Weder S, Keller M, Fischer M, Becker K, Alexy U. Intake of micronutrients and fatty acids of vegetarian, vegan, and omnivorous children (1-3 years) in Germany (VeChi Diet Study). Eur J Nutr. 2022 Apr;61(3):1507-1520. doi: 10.1007/s00394-021-02753-3. Epub 2021 Dec 2. PMID: 34855006; PMCID: PMC8921058.

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