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Health Information | 04/04/2023

Plant-based, Vegetarian, and Vegan Diets: What’s the Difference?

By  Kathryn Wilson, MS, RD, LDN, CNS
The popularity of plant-based, vegetarian, and vegan diets has risen tremendously over the past decade. Many people might have various motivations for changing their diet, including personal, religious, environmental, or financial reasons. And while these diets seem similar, they have distinct differences. Learning more about each type can help you find the right choice for your lifestyle and long-term health.

What is vegetarianism?

A vegetarian diet eliminates meat, such as poultry, pork, and fish. There are several types of vegetarian diets, each varying in what foods you can and cannot consume. Vegetarian diets include flexitarian, pescatarian, lacto-ovo vegetarian, lacto vegetarian, and pollo vegetarian. A vegan diet is a type of vegetarian diet that excludes some additional foods, which are explained below. As the name suggests, a flexitarian diet allows room for flexibility in the foods you eat. This means that although individuals mostly consume vegetarian foods, they might occasionally eat meat and fish. A lacto-vegetarian diet excludes meat, fish, poultry, eggs, and foods containing them. Dairy products, such as milk, cheese, yogurt, and butter, are allowed. A lacto-ovo vegetarian diet excludes meat, fish, and poultry but allows for consuming dairy products and eggs. A pescatarian diet allows fish, other seafood, dairy products, and eggs. With this diet, meat of any kind (i.e., beef, pork, bison) is not consumed. Chicken is allowed in a pollo vegetarian or pollotarian diet, but beef and pork are not.

What is veganism?

A vegan diet excludes all animal products, including meat, poultry, fish, dairy, and eggs. There are varying levels of veganism as well. Many vegans exclude honey from their diet and can go as far as cutting out animal products in all aspects of life, such as beauty products, shoes, and clothing. The rise of cruelty-free cosmetics and materials like vegan leather has made these choices more popular and accessible.

What is a plant-based diet?

A plant-based diet focuses on increasing the intake of “plant foods” but does not automatically exclude animal products. Plant foods include:
  • Vegetables
  • Fruits
  • Legumes
  • Whole grains
  • Nuts & seeds
While it may seem similar to veganism or vegetarianism, plant-based diets differ slightly. For example, a vegan diet eliminates all animal products, while a plant-based diet simply focuses on increasing the intake of fruits, vegetables, nuts, seeds, and whole grains while allowing flexibility to eat animal products on occasion. The motivation for following a vegetarian versus a plant-based diet can be different. While vegans and vegetarians often make that choice based on ethics or belief systems, the choice to follow a plant-based diet is often motivated by a desire to improve one’s health. Additionally, people following a plant-based diet may exclude foods allowed in other diets. The greater emphasis on whole, unrefined, unprocessed natural foods means that something like potato chips, despite being vegan and vegetarian, don’t fit into a plant-based diet because they are heavily processed and unhealthy. Of course, the level of discipline may vary from person to person, as these lifestyle choices are meant to be sustainable.

Benefits & Risks 

Adopting a vegetarian, vegan, or plant-based diet can be a highly nutritious choice if done with care. Vegans and vegetarians tend to eat more foods that are high in vitamins C and E, dietary fiber, potassium, and magnesium. Eating these nutrient-rich foods instead of meat might also lower blood pressure and cholesterol. A study by the American Heart Association showed that people who eat mostly plant-based foods had a 16% lower risk of developing heart attacks, strokes, and heart failure and a 32% lower risk of dying from those diseases. With these benefits in mind, it's important to note that reducing or eliminating animal products in the diet is not always the best choice for everyone. Animal foods such as meat, eggs, and dairy contain important nutrients, including protein, iron, calcium, zinc, vitamin B12, and vitamin D. People following a vegetarian, vegan, or plant-based diet should take extra care to ensure they are consuming plant foods that also contain these nutrients, and in some cases may require additional vitamin supplementation to meet their needs. When reducing or eliminating animal foods, it is important to replace them with high-nutrient-value plant foods such as beans, nuts, seeds, whole grains, fruits, and vegetables. In most cases, this involves additional planning and food preparation. A registered dietitian is a healthcare provider equipped to help people adopt dietary changes in a way that is healthful and sustainable and may be a useful resource when switching to a vegetarian, vegan, or plant-based diet. If you are interested in incorporating any of these diets into your lifestyle, ask your Atrius Health provider for a referral to meet with a registered dietitian/nutritionist to find the right fit for you.

About The Author

Kathryn Wilson, MS, RD, LDN, CNS

Kathryn Wilson, MS, RD, LDN, CNSC, joined Atrius Health in 2022 and sees patients at our Copley and Wellesley locations. Kathryn’s specialties include pediatric nutrition, eating disorders, and enteral nutrition.

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