What Are the Differences in Plant-Based Types of Diets?

Sharon Palmer

Published on January 23, 2024

Wondering what are the differences in plant-based types of diets? I’m answering your top questions on a variety of plant-based diet patterns, from vegan and vegetarian to flexitarian and pescatarian.

There are so many versions of plant-based diets. You’ve got vegan, vegetarian, lacto vegetarian, ovo vegetarian, lacto ovo vegetarian, pescatarian, flexitarian, semi-vegetarian, pescatarian, and polo vegetarian. And some people even fall in between these diet patterns. Throw in other diet preferences layered upon these diets, like gluten-free or nut-free, and it gets more complicated. No wonder I get so many questions on the different types of plant-based diets in my work as a plant-based dietitian. What’s the difference between vegan and vegetarian diets? Is one plant-based diet better than others for your health and the planet? What about flexitarian and pescatarian eating? That’s why I’m answering some of your top questions about these different types of diets in my Ask Sharon feature on the blog today. Read more about my advice on the differences between vegetarian and vegan diets here.

Plant-based diets center upon eating a variety of plant foods, such as found in this recipe for Vegan Chana Masala.

Question: How do you define plant-based?

Sharon’s Answer:

“Plant-based” doesn’t have a formal definition, although there is a movement to create a formal definition for it when it is used as a term on food labels. Surveys show that “plant-based” means different things to different people. Researchers and health experts often use the term to mean a diet based on primarily plants, while chefs, restaurants and food companies use the term to be 100% plant-based—or vegan. Consumers use the term in different ways. Increasingly, it’s becoming synonymous with vegan—completely plant-based.

Question: What is a vegan diet?

Sharon’s Answer:

A vegan diet is 100% plant-based, meaning it excludes all animal flesh (including poultry, fish, and red meat), dairy products (milk, cream, butter, yogurt, cheese), eggs, and honey. Some people follow different forms of vegan diets. For example, some vegans are extremely careful, and do not eat in restaurants where equipment touches animal foods, while others may be less cautious.

Many traditional diets have beautiful plant-based dishes, such as this Vegetable Tofu Pancit from the Philippines.

Question: Are there any benefits to plant-based diets?

Sharon’s Answer:

Research shows that there are health benefits for plant-based diets, including vegetarian and vegan diets. These benefits include reduced risks of obesity, hypertension, diabetes, heart disease, and cancer. In addition, there are environmental benefits linked with these eating patterns—in particular vegan diets.

Question: How do you define vegetarian?

Sharon’s Answer:

Vegetarian is defined as avoiding all flesh from animals, including fish, poultry, and red meat, but it allows for eggs and dairy products. There are benefits for this eating pattern, as noted above. It is easier to meet your nutrient needs on a vegetarian diet—you have to be a little more careful and strategic on a vegan diet to make sure you get all of your essential nutrients.

Rely on easy recipes to make plant-based eating a cinch, such as this Jackfruit Black Bean and Quinoa Tacos.

Question: In terms of subtypes, what are lacto-vegetarian, ovo-vegetarian, and lacto-ovo vegetarian diets?

Sharon’s Answer:

Vegetarian diets are generally considered to be lacto-ovo vegetarian diets. Lacto vegetarians eat no animal flesh, nor eggs, but do eat dairy products. Ovo vegetarians eat no dairy products and no animal flesh, but they do eat eggs. It’s important to note that even within vegetarian diets, there are people who eat differently than these prescribed diet patterns, and they may call themselves “vegan”, “plant-based”, or “vegetarian”. People may be vegan, but when they travel switch to vegetarian to make it easier. Or they may be vegetarian, but a few times a year make an exception in their diets. I know vegetarians that will occasionally eat fish. There are no fast rules about how people manage their eating styles. It’s a personal preference.

Question: How would you classify a pescatarian?

Sharon’s Answer:

This diet avoids all animal flesh, except for seafood and fish, but allows for dairy and eggs too. Some people may be entirely vegan, but eat a small amount of fish, while others may be vegetarian and eat a certain amount of fish. There are different expressions of this diet.

Question: How would you classify a pollotarian?

Sharon’s Answer:

This would be a vegetarian diet, which excludes all animal flesh, but allows for chicken only, on top of dairy and eggs. Many people may avoid red meat, so they might fall into this category.

Question: How would you classify a flexitarian?

Sharon’s Answer:

A flexitarian diet doesn’t have a formal definition regarding what percentage of the diet is plant-based, but it is an overall diet plan primarily based on plants. Flexitarians (also called semi-vegetarians) may eat a large proportion of vegetarian meals during the week, but they are not exclusively vegetarian every day. In general, flexitarians try to limit their meat consumption.

The secret to plant-based eating is to include a variety of pulses, grains, and vegetables in your meals. Try this recipe for Roasted Asparagus with Harissa-Spiced Sorghum.

Question: Are there any other types of vegetarian eating options?

Sharon’s Answer:

There is also a diet called “whole foods plant-based,” which has come to mean a diet based solely on unrefined plant foods, so this diet typically excludes refined oil, sugars, and salt. People may have additional dietary preferences within plant-based eating patterns, such as “clean” eating (an undefined diet term that includes habits like avoiding pesticides, chemicals, and preservatives in foods), specific food allergies, or gluten-free eating because of conditions like celiac disease. However, I recommend that if you are following a vegetarian or vegan diet you should not place additional restrictions upon your diet because of a food fad, such as going gluten-free, soy-free, or grain-free, because you think it’s “healthy”. You need these food groups to meet your nutrient needs. If you have a medical condition such as a known food allergy or celiac disease, that’s another scenario. I suggest you make an appointment with a plant-based dietitian to help you plan a diet that meets your needs.

Include a balance of grains, vegetables, and plant proteins in your meals. Try this recipe for Swiss Chard Pecan Lasagna.

Question: What should you base a decision to eat vegetarian on?

Sharon’s Answer:

It should be based on your personal health and values goals and your preferred eating style. There are a lot of reasons to go vegan or vegetarian. You can gain health benefits, reduce your impact on the planet, and reduce the suffering of animals in agriculture. If those are important values to you, you may want to consider it. At the very least, everyone can eat a more plant-based diet. Check out my tips on how to go plant-based.

Question: Are there any supplements vegans and vegetarians and should consider?

Sharon’s Answer:

Yes, vegans should be sure to supplement with vitamin B12—even vegetarians should supplement their diets with B12. In addition, it’s important to get enough protein, zinc, iron, omega-3 fats, and vitamin D. Learn more about my recommendations in this blog. Download my FREE Go Vegan Toolkit here.

Check out other nutrition questions I’m answering at The Plant-Powered Dietitian:

Main image: Mediterranean Sheet Pan Veggies, Sharon Palmer, MSFS, RDN