Vegetarian Diets 101

Sonja Carlson, UNH Extension Intern, Nutrition Connections
  • Bowls with various vegetables, whole grain, sour cream and gaucamole

The power of plants.

When you hear the term vegetarian or vegan, many people automatically think of diet restrictions and bland meals. On the contrary, vegetarianism can open your world to a variety of new flavors and foods, even bringing along some additional health benefits.

What is a vegetarian diet?

Following a vegetarian diet means not eating animal meat and instead incorporating a variety of plant-based foods such as grains, fruits, veggies, legumes, nuts and seeds. While vegetarian diets typically eliminate meat, poultry or fish, there are different ranges in what foods people choose to include or exclude:

  1. Lacto-vegetarian diets exclude meat, fish, poultry, and eggs, as well as any foods that contain these products. They include dairy products, such as milk, cheese, yogurt, and butter.
  2. Ovo-vegetarian diets exclude meat, poultry, seafood, and dairy products, but allow eggs.
  3. Lacto-ovo vegetarian diets exclude meat, fish, and poultry, but allow dairy products and eggs.
  4. Pescatarian diets exclude meat and poultry, dairy, and eggs, but allow fish.
  5. Vegan diets exclude meat, poultry, fish, eggs and dairy products as well as foods that contain these products11.

Is it healthier to be vegetarian?

Eating vegetarian often consciously encompasses eating more fruits, vegetables, legumes, whole grains, nuts, seeds, and oils, all of which are beneficial to one’s diet. All these foods are more nutrient dense and contain more vitamins, minerals, and fiber. These dietary components can then promote…

  • Gut health2
  • Heart health2
  • Better management of blood sugar, cholesterol, and body weight2
  • Lower risk of overweight or obesity3
  • Lower risk of certain heart diseases4
  • Slightly lower risk for certain cancers4
  • Lower risk for diabetes4

What are potential risks with eating vegetarian?

If not well planned, abruptly changing to a vegetarian diet may lead to nutrient deficiencies. Some of the major macronutrient and micronutrient deficiencies would be protein, vitamin B12, vitamin D, omega-3 fatty acids, calcium, iron, and zinc.5 Making a conscious effort to eat more fortified foods (breakfast cereals, bread, fruit juices) and having a diverse diet can help mitigate these deficiencies.5 Many vegetarian or vegan substitutes tend to be highly processed and manufactured to look like their animal-based counterparts. Therefore, while everything is good in moderation, you want to make sure you are limiting consumption of these processed alternatives and are instead sticking to whole foods.

Steps to become a successful vegetarian.

Since the American diet is largely animal-based, shifting to a vegetarian diet slowly can help make this change more attainable and sustainable. Below is a potential outline of how to change your diet, to one that is vegetarian.

Step 1. Add more vegetables and legumes to meals

Step 2. Incorporate vegetarian protein options such as tofu and beans

Step 3. Start eliminating meat at your own pace. Whether you choose to further eliminate fish/seafood, dairy and eggs is up to you!

Step 4. Experiment with new recipes and have fun with it! (This is key to make this diet change worthwhile and something that is sustainable for you)

The ultimate vegetarian food list to get all your essential nutrients.

To meet your nutritional needs, food shopping requires some extra thought to make sure you’re getting all your essential macronutrients (carbohydrates, fat, protein) and micronutrients (vitamins and minerals).

Vegetarian protein sources: Helps with growth and repair6

  • Tofu
  • Tempeh
  • Seitan
  • Legumes

Vegetarian calcium sources: Helps with bone health, most plant-based milk options are fortified with calcium and vitamin d6

  • Almond milk
  • Cashew milk
  • Oat milk
  • Coconut milk
  • Soy milk
  • Dark leafy greens (kale, spinach, broccoli, collard greens)
  • Calcium fortified cereals and juices

Vegetarian sources of B12 vitamins: Helps with red blood cell development and prevention of anemia7

  • Nutritional yeast
  • Fortified cereals
  • Fortified soy products (tofu, soy milk)

Vegetarian sources of iron: Since iron from plant-based sources (as opposed to iron from animal sources) is not absorbed as easily, it is recommended to pair with foods that are rich in vitamin C such as citrus fruits, strawberries, and tomatoes6

  • Beans
  • Dark leafy greens
  • Dried fruits
  • Iron fortified cereals
  • Lentils
  • Peas
  • Whole grains

Vegetarian sources of omega 3s: Important for heart health and brain development

  • Seeds (chia, flax, hemp, pumpkin)6
  • Seaweed
  • Soybeans
  • Walnuts


  1. Dagnelie PC, Mariotti F. 1 - Vegetarian Diets: Definitions and Pitfalls in Interpreting Literature on Health Effects of Vegetarianism. In: Mariotti F, ed. Vegetarian and Plant-Based Diets in Health and Disease Prevention. Academic Press; 2017:3-10. doi:10.1016/B978-0-12-803968-7.00001-0
  2. Pilis W, Stec K, Zych M, Pilis A. Health benefits and risk associated with adopting a vegetarian diet. Rocz Panstw Zakl Hig. 2014;65(1):9-14.
  3. Appleby PN, Key TJ. The long-term health of vegetarians and vegans. Proc Nutr Soc. 2016;75(3):287-293. doi:10.1017/S0029665115004334
  4. Hemler EC, Hu FB. Plant-Based Diets for Personal, Population, and Planetary Health. Adv Nutr. 2019;10(Suppl_4): S275-S283. doi:10.1093/advances/nmy117
  5. Craig WJ. Nutrition concerns and health effects of vegetarian diets. Nutr Clin Pract. 2010;25(6):613-620. doi:10.1177/0884533610385707
  6. Agnoli C, Baroni L, Bertini I, et al. Position paper on vegetarian diets from the working group of the Italian Society of Human Nutrition. Nutr Metab Cardiovasc Dis. 2017;27(12):1037-1052. doi: 10.1016/j.numecd.2017.10.020
  7. Rizzo G, Laganà AS, Rapisarda AM, et al. Vitamin B12 among Vegetarians: Status, Assessment and Supplementation. Nutrients. 2016;8(12):767. Published 2016 Nov 29. doi:10.3390/nu8120767
Sonja Carlson, UNH Extension Intern, Nutrition Connections

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