Vegetarian and Vegan Diets: Types, Protein and Nutrients
Author: Disabled World (DW)
Updated/Revised Date: 3 Nov 2026
Table of Contents:
Synopsis - Definition - About This Section - FAQs - Publications - Subtopics
Synopsis
Learn the differences between vegetarian and vegan diets, from lacto-ovo to pescatarian, plus plant sources of protein, calcium, iron and vitamin B12.
At a Glance
- 1 - A raw vegan diet uses unprocessed foods not heated above 115 degrees Fahrenheit.
- 2 - About 4 percent of U.S. adults are vegetarian and 1 percent are vegan, according to Gallup.
- 3 - Vitamin B12 is found naturally only in animal foods, so vegans need fortified foods or a supplement.
- 4 - Pescatarians avoid meat and poultry but eat fish, while flexitarians eat a mostly vegetarian diet with occasional meat.
Topic Definition
- Vegetarian and Vegan Diets
Vegetarian and vegan diets are plant-based eating patterns that exclude the flesh of animals, though they differ in how strictly they draw that line. A vegetarian lives mainly on foods from the plant kingdom and may or may not include eggs and dairy, while a vegan goes further by avoiding eggs, dairy, and every other animal-derived product. Between these two are several recognized variations, such as lacto-vegetarians who keep dairy, ovo-vegetarians who keep eggs, and lacto-ovo-vegetarians who keep both. Others sit closer to the edges, including flexitarians who eat meat occasionally and pescatarians who avoid all meat apart from fish. People adopt these diets for reasons ranging from health and weight management to ethics, and doing so successfully means planning ahead to cover nutrients like protein, calcium, iron, and vitamin B12 from suitable plant or supplement sources.
Overview
A vegetarian diet leaves out meat, poultry and fish, and a vegan diet goes further by leaving out all animal products, including dairy, eggs and usually honey. People choose these diets for health, ethical, environmental or religious reasons. The Academy of Nutrition and Dietetics states that appropriately planned vegetarian and vegan diets are healthful, nutritionally adequate and suitable for all stages of life, including pregnancy, childhood and older age, as well as for athletes [Melina, Craig and Levin, 2016].
About 4 percent of U.S. adults say they are vegetarian and about 1 percent say they are vegan, according to a 2023 Gallup poll [Gallup, 2023].
Types of Vegetarian and Vegan Diets
- Vegan: eats only plant foods, such as vegetables, fruits, grains, legumes, nuts and seeds, with no meat, fish, dairy or eggs. A raw vegan diet consists of unprocessed vegan foods that have not been heated above 115 degrees Fahrenheit (46 degrees Celsius).
- Lacto-ovo vegetarian: eats dairy products and eggs but no meat, poultry or fish. This is the most common type of vegetarian diet ("lacto" comes from the Latin for milk, and "ovo" for egg).
- Lacto-vegetarian: eats dairy products but no eggs, meat, poultry or fish.
- Ovo-vegetarian: eats eggs but no dairy products, meat, poultry or fish.
- Pescatarian: avoids meat and poultry but eats fish and seafood, and often dairy products and eggs.
- Vegaquarian: an informal term for someone who eats vegetables, grains, dairy products and fish.
- Semi-vegetarian or flexitarian: eats a mostly vegetarian diet but includes meat, poultry or fish occasionally.
- Macrobiotic: a diet based mainly on whole grains, vegetables and beans, which may include occasional fish.
Becoming a Vegetarian or Vegan
You may want to start slowly and work your way toward a fully vegetarian diet. Instead of cutting out meat abruptly, try a few meat-free days a week, or replace red meat with fish or chicken before phasing those out if that is your goal. An important part of the change is learning which foods supply the nutrients you used to get from meat, fish, eggs or dairy, and planning meals so that nothing is missing.
Many people who switch say they feel better and find it easier to manage their weight. Well-planned vegetarian diets are linked to lower cholesterol, lower blood pressure, and lower rates of heart disease and type 2 diabetes, but these benefits depend on eating mainly whole foods rather than sweets and highly processed products.
Protein
Being vegetarian does not mean your diet will be short on protein. Most adults need about 0.8 grams of protein per kilogram of body weight a day, or about 55 grams for a person who weighs 150 pounds, and a varied vegetarian diet with enough calories usually provides this. Good sources include beans, lentils and peas; soy foods such as tofu, tempeh and soy milk; nuts and seeds; whole grains; and, for lacto-ovo vegetarians, eggs and dairy products. Plant foods eaten over the course of the day supply all the essential amino acids, so proteins do not need to be combined at each meal.
Calcium
Dairy products are a convenient source of calcium, but vegans can get enough from calcium-set tofu, fortified plant milks and orange juice, kale, collard greens, bok choy, broccoli, almonds, sesame seeds and white beans. Spinach contains calcium, but little of it is absorbed because spinach is high in oxalate.
Iron and Zinc
Beans, lentils, tofu, fortified cereals, whole grains, dark leafy greens, nuts and seeds supply iron, but the iron in plant foods is less easily absorbed than the iron in meat. Eating foods rich in vitamin C, such as citrus fruit, peppers or tomatoes, at the same meal helps the body absorb more iron. Vegetarians may also need more zinc than meat eaters; good sources include beans, whole grains, nuts, seeds and dairy products.
Vitamin B12
Vitamin B12 is found naturally only in animal foods, so vegans need a reliable source, such as fortified breakfast cereals, fortified plant milks, fortified nutritional yeast or a B12 supplement [National Institutes of Health, Office of Dietary Supplements, n.d.]. Lacto-ovo vegetarians get some B12 from dairy products and eggs. The body can store vitamin B12 for several years, so a deficiency may take a long time to appear, but it can cause anemia and lasting nerve damage, so it is not safe to rely on stored B12.
Vitamin D and Omega-3 Fats
The skin makes vitamin D in sunlight, and vitamin D is also added to many milks, plant milks and cereals. Vegans who get little sun may need a supplement. Flaxseed, chia seeds, walnuts, canola oil and soy supply the plant omega-3 fat alpha-linolenic acid (ALA), and people who eat no fish may want to ask a doctor about an algae-based supplement of the longer-chain omega-3 fats EPA and DHA.
Plan Your Diet
Before changing your diet, learn which nutrients you might miss. A registered dietitian can help you plan balanced meals, and if your needs are still not met, ask your doctor about supplements suited to you. This is especially important for children, teenagers, pregnant or breastfeeding women, older adults and people with health conditions.
Frequently Asked Questions
Is a vegetarian diet safe for children and teenagers?
Yes, a well-planned vegetarian diet can support children and teenagers, though extra attention to zinc is helpful because it aids growth during the teen years.
Can athletes build muscle on a vegan diet?
Yes, athletes can build muscle on a vegan diet by eating enough total calories and combining protein sources such as legumes, soy, whole grains, nuts, and seeds throughout the day.
How is a plant-based diet different from a vegan diet?
A plant-based diet centers on foods from plants but may still include small amounts of animal products, while a vegan diet excludes all animal products entirely.
Do vegetarians need to combine foods to get complete protein?
No, eating a variety of plant foods across the day supplies all essential amino acids, so protein sources do not need to be combined at a single meal.
Are meat substitutes healthy for vegetarians?
Meat substitutes can fit a vegetarian diet, but many are processed and high in sodium, so checking labels and favoring whole plant foods is a sensible approach.
What are the main environmental reasons people choose vegetarian diets?
Many people choose vegetarian diets to reduce land use, water use, and greenhouse gas emissions linked to raising animals for food.
How long does it take to adjust to a vegetarian diet?
Adjustment varies by person, though easing in gradually over several weeks helps the body adapt and makes the change easier to maintain.
Can a vegetarian diet lower the risk of heart disease?
Studies link well-planned vegetarian diets to lower cholesterol, lower blood pressure, and lower rates of heart disease and type 2 diabetes. The benefits depend on choosing whole foods rather than sweets and highly processed products.
References
- Gallup. (2023). Snapshot: Few Americans vegetarian or vegan.
- Melina, V., Craig, W., and Levin, S. (2016). Position of the Academy of Nutrition and Dietetics: Vegetarian diets. Journal of the Academy of Nutrition and Dietetics, 116(12), 1970-1980.
- National Institutes of Health, Office of Dietary Supplements. (n.d.). Vitamin B12: Fact sheet for health professionals.
Curated and edited by Ian C. Langtree, Founder and Editor-in-Chief, Disabled World. This section is maintained by the Disabled World editorial team. Last updated: