Plant-Based Diet vs. Vegetarian Diet: What’s the Difference?

Last updated on March 25, 2021 at 02:13 pm

Plant-Based vs Vegetarian: Do you know the difference? Everyone knows a vegetarian, but have you recently heard one of your friends or family members describe their diet as plant-based?

At first, these might seem like the same thing, and in a lot of ways, they are. There is no major conflict between plant-based diet vs. vegetarian diets, and many people’s diets fit into both categories.

But there are some differences between these two types of diets and how the terms are used.

Which term is used can tell a lot about the person’s motivations and reasons for following this diet. It also suggests a thing or two about what the person might and might not eat.

What Is a Vegetarian Diet?

The word vegetarian refers to any number of diets that restrict animal products, either partly or entirely. Each vegetarian diet differs in terms of which animal products are restricted and which are allowed. It’s really a personal choice.

While there are no hard and fast rules, there are several common kinds of vegetarian diets which include:

Lacto-ovo-vegetarian: excludes all forms of meat but allows dairy and eggs
Ovo-vegetarian: excludes all forms of meat and dairy but allows eggs
Lacto-vegetarian: excludes all forms of meat and eggs but allows dairy
Vegan: excludes all foods of animal origin, often includes honey
Pesco-vegetarian: excludes red meat and poultry but allows fish

As you can see, vegetarian diets can differ greatly from each other. People adapt their own diets to their own needs. Several common reasons for following some kind of vegetarian diet include:

Reduced environmental impact
Protection of animal welfare
Improved health outcomes
Reduced food cost

Where Does Vegetarianism Come From?

The most common modern definition of a vegetarian diet today is one who primarily focuses on plant-based foods, excludes meat, but still includes animal proteins and products such as dairy (i.e milk, cheese, butter), and eggs.

Historically, people all over the world have embraced vegetarian diets. Some entire cultures embrace the diet, as is the case in Hinduism. And these cultures have developed whole cuisines based on their vegetarian diets.

In the Western world, vegetarianism has always existed within a society of mostly meat-eating people, though it has always been the diet followed by the minority of the population in the West. Famous vegetarians throughout history include Isaac Newton and Pythagoras.

As various kinds of vegetarian and vegan diets become more popular in modern times, many people are looking for information about these diets and their effects. And with so many different terms out there, it can be difficult to find the right information.

Since the word vegetarian has such a broad definition, groups of people have sought to introduce new terms to further define their own lifestyles or diets. Vegan and plant-based are two such terms.

Vegan and Plant-Based Diets

According to Eva Batt’s essay, the vegan movement arose in the 1950s out of a meeting set up by a group of so-called “total vegetarians” who completely rejected the notion of exploiting animals for human gain (1).

Vegan lifestyles restrict all animal products, not just in the diet but in all areas of life. Vegans may not wear leather or use cosmetics that have been tested on animals or contain animal-derived ingredients.

Many kinds of vegetarians may also choose to incorporate some of these non-dietary practices into their lifestyles, so vegetarianism can be more than just a food-based philosophy. Depending on the reasons behind it, it can be a lifestyle as much as a diet.

The term plant-based diet is one of the alternative terms that was coined to talk about vegetarian diets in a more nutrition-focused way.

Nutritionists and scientists wanted to discuss these diets without evoking the non-diet-related elements of veganism and vegetarianism, partially because some of those ideas were culturally or politically controversial at the time.

So what was it about plant-based diets that nutritionists were so eager to discuss?

Plant-Based Diets and Health

Thomas Colin Campbell is an American biochemist famous for his decades-long advocacy of a plant-based diet to improve the health of Americans.

He was the lead researcher in the China-Cornell-Oxford Project, a large epidemiological study of 6,500 subjects in rural China, commonly referred to as ‘The China Study’ (2).

The study examined the prevalence of various diseases in this population and compared their incidences with the subjects’ dietary choices.

In his book based on the findings of this study, Campbell outlines how this evidence associates positive long-term health outcomes with eating a plant-based diet (3).

What Is a Plant-Based Diet?

Plant-Based vs Vegetarian – We’re still looking for answers. A plant-based diet is any diet that consists mostly of foods that come from plants. That means that small amounts of animal products can be included in the diet.

Limited amounts of them won’t necessarily negate the health gains and can even improve them further. Under this definition, around 80% of the world follows a plant-based diet according to this study (4).

Throughout most of human history and in most places in the world today, plant-based diets have been and are the norm. While approximately two billion people now eat a largely animal-based diet, including the average American diet, this is not necessarily the norm from a historical perspective.

However, most of the time you hear about plant-based diets in a Western context, it is a diet followed by a minority of people.

The use of the term has become more popular as scientists and nutritionists use it to talk about the health benefits of eating plant-based foods when compared to animal foods.

While following a plant-based diet can also reduce your environmental footprint and decrease the demand for the industrial meat industry, these aren’t usually the main focuses when people talk about plant-based diets.

Whole-Food, Plant-Based Diets

For Thomas Colin Campbell, a plant-based diet is about more than simply avoiding animal products. The biochemist has publicly advocated for whole-food, plant-based diets since the early 1980s.

In his book Whole, Campbell brings together decades of research to support his convictions (5).

While he believes that a plant-based diet provides the best protection against heart disease and other life-threatening conditions when compared to animal-based foods, he also emphasizes the importance of unprocessed, whole foods over refined flours, oils, and sugars.

In his view, a vegetarian diet consisting of white bread, soda, and salty snacks aren’t likely to do anyone much good. Instead, he advocates eating mainly from the following food groups which are shared between the Plant-Based vs Vegetarian diet:

Whole grains: unprocessed grains and cereals including oats, whole wheat, brown rice, quinoa, and others.
Vegetables: any fresh vegetables, especially dark leafy greens like chard and spinach and cruciferous vegetables like broccoli and Brussels sprouts.
Fruits: fresh fruits, especially those with less sugar such as bananas and strawberries. Juicing fruits is discouraged since it removes the fiber.
Tubers: root vegetables including potatoes, sweet potatoes, carrots, parsnips, and others.
Legumes: Beans and pulses including lentils, chickpeas, kidney beans, and others.

Such a diet can also include nuts, seeds, tofu, tempeh, whole-grain flours, and plant-based milks.

Health Benefits of a Plant-Based Diet

There are numerous, evidence-backed health benefits associated with following such a plant-based diet, the first of which is weight loss.

A meta-analysis of 12 intervention-based studies involving over 1,000 subjects found that those assigned to a whole-food, plant-based diet lost 4.5 lb more weight over a two-week period than those on other diets (6).

The reason is that a whole food diet contains a lot of dietary fiber and a greater quantity of complex rather than simple carbohydrates. These take a lot longer to digest than processed grains and sugars, meaning you feel full for longer.

Aside from making your energy levels more consistent over the course of a day, this also helps you consume less overall calories by reducing your food intake, especially from snacking.

Whole foods are also important for reducing the risk of heart disease. A Cambridge University study found a strong correlation between increased consumption of whole grains and a lower incidence of coronary diseases (7).

The strongest evidence for the efficacy of the whole-food, plant-based diet comes from the combined data of two large observational studies: the Nurses’ Health Study and the Health Professionals’ Follow-Up Study.

These studies tracked over 130,000 subjects over more than twenty years to associate dietary choices with incidences of various diseases.

In an analysis of the data from these studies, it was shown that whole, plant-based foods reduced the risk of coronary heart disease, strokes, some cancers, and other conditions (8).

Plant-based diets that included more processed foods were associated with a less significant improvement in incidences of these same diseases.

Plant-Based Diets and Type 2 Diabetes

A comprehensive review by renowned expert Janette Brand-Miller shines a light on why whole foods have the health benefits they do (9).

When you eat food, your body releases insulin to regulate your blood sugar levels. Foods that digest more quickly, like sugars and processed grains, cause insulin to spike more quickly.

However, a meal of vegetables and brown rice is rich in complex carbohydrates and fiber, so it takes much longer to break down, therefore preventing a large spike in insulin and blood sugar.

Recent evidence also supports the relationship between plant-based diets and type-2 diabetes. In fact, three intervention studies found that plant-based diets reduced the incidence of type-2 diabetes (10).

Cardiovascular Health and Plant-Based Diets

One review analyzed the link between plant-based diets and coronary heart disease (11). It found that a plant-based diet was protective against atherosclerosis, a key cause of coronary artery disease.

Another study of a large community-based cohort in the US found that participants who followed a healthy, plant-based diet had a lower risk of developing, and dying from, cardiovascular disease (12).

Does a Plant-Based Diet Fight Cancer?

Evidence is emerging that plant-based diets have a preventative effect on multiple forms of cancer. The American Institute for Cancer Research recommends in its Cancer Prevention Guidelines that a whole-food, plant-based diet provides the best protection against many forms of cancer (13).

In particular, breast, prostate, colorectal, and gastrointestinal cancers have been extensively studied, according to a 2018 review (14). The evidence shows that one’s risk for these forms of cancer can be reduced by adhering to a plant-based diet.

For example, one study found a 47% increase in breast cancer risk among study participants who ate grilled, barbecued, or smoked meat (15).

In this study of women diagnosed with breast cancer, subjects who switched to a plant-based diet and exercised moderately experienced a 50% lower mortality rate after two years when compared to those who ate meat (16).

The Bottom Line

In practice, Plant-Based vs Vegetarian can be identical. Many diets fit under both categories, and there is always some degree of interpretation associated with these terms.

The more important thing to know is not to think about Plant-Based vs Vegetarian but rather what your goals are when choosing to eat more plant-based foods.

For people looking to eat more plant-based foods but who don’t necessarily want to give up animal products or meat entirely, the term plant-based diet avoids the ethical and environmental implications of terms like vegetarianism. Plant-based is also a term commonly associated with a whole-food diet.

No matter what your dietary choices are, there’s no doubt that eating more fresh fruits and vegetables has a positive effect on your health, whether you choose to be a vegetarian or a plant-based eater.