What is a Vegetarian Diet?

What is a Vegetarian Diet? Vegetarian Diet 101.

The Basics of a Vegetarian diet

A vegetarian diet is one of the three healthy eating patterns highlighted in the 2020-2025 Dietary Guidelines for Americans. In fact, vegetarianism has been practiced for centuries in various civilizations around the world, with written references going as far back as the sixth century AD in Europe. At its core, a vegetarian diet omits meat, poultry and fish. However, there are several types of vegetarian diets that have additional allowances and/or restrictions. This article will focus on the different types of vegetarian diets, explore research around the benefits of a vegetarian diet and underscore the nutrients that vegetarians should ensure they get enough of.

Types of vegetarian diets

There are several varieties of a vegetarian diet, including:

  • The lacto-ovo-vegetarian diet: Eliminates meat, fish and poultry but allows eggs and dairy products.
  • The lacto-vegetarian diet: Eliminates meat, fish, poultry and eggs but allows dairy products.
  • The ovo-vegetarian diet: Eliminates meat, fish, poultry and dairy products but allows eggs.
  • The pescatarian diet: Eliminates meat and poultry but allows fish; sometimes allows eggs and dairy products.
  • The vegan diet: Eliminates meat, fish, poultry, eggs and dairy products, as well as other animal-derived products such as honey.

Some diets are not considered vegetarian but share overlapping principles. One example is the flexitarian diet, which is a flexible eating style that emphasizes the addition of plant or plant-based foods and beverages, incorporates dairy and eggs and encourages meat to be consumed less frequently and/or in smaller portions.

What Foods Make Up a Vegetarian Diet?

Despite there being different kinds of vegetarian diets, the following types of foods are emphasized within each of them:

  • Fruits: apples, bananas, berries, oranges, melons, papaya, pears and peaches.
  • Vegetables: asparagus, bell peppers, bok choy, broccoli, carrots, eggplant, leafy greens, okra, tomatoes and yams.
  • Grains: amaranth, barley, buckwheat, oats, quinoa, rice and wheat.
  • Legumes: chickpeas, lentils, beans and peas.
  • Nuts: almonds, cashews, chestnuts, peanuts and walnuts.
  • Seeds: chia, hemp seeds and flaxseeds.
  • Healthy fats: avocados, olives and olive oil.
  • Proteins: natto, nutritional yeast, tempeh, tofu, seitan, spirulina, eggs (in some varieties) and dairy products (in some varieties).

Vegetarian Diets and Health

A vegetarian diet can have a positive impact on one’s health. Below are a few of the key benefits:

Dietary Sources of Vitamins and Minerals

Vegetarian diets are intended to be rich in various plant-based foods, which contain many vitamins and minerals that are healthful, including vitamins A, C, E, K and folate, and the minerals potassium, phosphorus, magnesium and manganese. These nutrients — some of which are not consumed in adequate amounts, are vital to the health of our eyes, immune system, muscles, heart, nerves, skin, gut, brain and more.

Heart Health Benefits

Vegetarian diets rich in fruits, vegetables and whole grains have been associated with heart health benefits. A systematic review and meta-analysis found that vegetarian diets lower blood concentrations of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and non-high-density lipoprotein cholesterol. A meta-analysis found that a vegetarian diet was associated with lower blood pressure.

Decreased Cancer Risk

Some research has found that vegetarian diets are associated with a decreased risk of certain cancers, including colorectal and breast cancer.

Improved Blood Glucose Management

Several studies have examined diets high in plant-based foods and their impacts on diabetes-related risks. Compared to non-vegetarian diets, various types — including lacto, lacto-ovo and even semi-vegetarian — of vegetarian diets are associated with significantly lower levels of blood glucose and reduced insulin resistance, as well as a reduced risk of developing type 2 diabetes mellitus.

Pay Attention to These Nutrients

There are a few nutrients that vegetarians should pay special attention to because they are primarily found in animal foods. These nutrients are mainly found in proteins like meat, poultry and fish and include omega-3 fatty acids as well as micronutrients like zinc, selenium, iron, iodine and vitamin B12. However, with careful attention and planning, it is possible to meet your nutrient needs on a vegetarian diet. Vegetarians should take care to incorporate a variety of nutritious choices, including fortified foods and/or dietary supplements when appropriate.

In Summary

Due to its association with numerous health benefits, the vegetarian diet is one of the three healthy dietary patterns highlighted in the 2020-2025 Dietary Guidelines for Americans. While there are a few types of vegetarian diets, all emphasize plant-based foods like fruits, vegetables, whole grains and legumes. Although there are a few nutrients that vegetarian diets can be low in, with thoughtful preparation it is possible to receive the nutrients you need while adhering to this diet.