What Is It Called If You Only Eat Vegetables? Understanding Plant-Based Diets

November 22, 2025 •

3 min read

In the animal kingdom, an organism that eats only plants is known as a herbivore. When it comes to human diets, the question, 'what is it called if you only eat vegetables?' has a more nuanced answer, covering various plant-based eating patterns like veganism.

Quick Summary

A diet consisting exclusively of plant-based foods, including vegetables, fruits, and grains, is most accurately called a vegan diet. For animals, the term is herbivore. Human diet variations exist, with vegetarians consuming some animal byproducts like dairy or eggs.

Key Points

Veganism: A person who truly only eats plant-based foods, including vegetables, is a vegan, as this diet excludes all animal products.
Herbivore: The biological term for an animal that subsists entirely on plant matter.
Vegetarianism: The practice of abstaining from meat, but often includes animal-derived products like dairy and eggs.
Fruitarianism: An extremely restrictive plant-based diet consisting mainly of fruits, which carries significant health risks.
Dietary Planning: A purely plant-based diet requires careful planning to ensure adequate intake of nutrients like B12, iron, and calcium.
Not Just Vegetables: A complete plant-based diet includes fruits, grains, legumes, nuts, and seeds for a balanced nutritional profile.

The Animal vs. Human Distinction

For animals, the term is straightforward. An organism that consumes only plant-based foods is a herbivore. This is a biological classification that describes the animal's natural diet and digestive system. For humans, however, the terminology is more complex because few people subsist solely on vegetables, but instead follow a more comprehensive plant-based regimen that includes fruits, grains, nuts, and seeds.

Diving Deeper: Veganism and Strict Plant-Based Diets

If a person truly ate only vegetables, such as carrots, lettuce, and broccoli, they would likely suffer from severe malnutrition. Most people who eliminate animal products follow a vegan diet. Veganism is a lifestyle and dietary pattern that excludes all animal products and animal-derived ingredients, including meat, poultry, fish, eggs, dairy, and honey. It is the most precise term for what people generally mean when they say they 'only eat plants.'

Other Variations of Plant-Focused Diets

Understanding the various plant-focused diets helps to clarify why the term "vegetarian" isn't a perfect fit for a person who avoids animal products entirely:

Lacto-ovo vegetarian: Excludes meat, fish, and poultry but includes dairy products and eggs.
Lacto vegetarian: Excludes meat, fish, poultry, and eggs but includes dairy products.
Ovo vegetarian: Excludes meat, fish, poultry, and dairy products but includes eggs.
Pescatarian: Excludes meat and poultry but includes fish and seafood, along with dairy and eggs. While not strictly vegetarian, it is often grouped with plant-focused diets.
Flexitarian: Primarily plant-based but includes occasional small amounts of meat, poultry, or fish.
Fruitarianism: An extremely restrictive vegan diet focusing primarily on raw fruits, and potentially nuts and seeds, that can be collected without harming the plant. This diet carries significant health risks.

Nutritional Considerations for a Plant-Based Diet

Adopting a plant-based diet, especially a vegan one, requires careful planning to ensure adequate nutrient intake. Essential nutrients that are easier to obtain from animal products, such as vitamin B12, iron, and calcium, need to be monitored and supplemented if necessary. Many plant-based foods are fortified with these nutrients to help fill the gaps. Protein needs can be met through a variety of plant sources like legumes, lentils, nuts, seeds, and tofu. A well-planned plant-based diet can be healthy and nutritionally adequate for all stages of life. For a deeper understanding of plant-based nutrition, resources from the Mayo Clinic are highly recommended.

Plant-Based vs. Vegetarian Diets: A Comparison

To better illustrate the differences, here is a comparison of some common dietary patterns:


Feature	Vegan	Lacto-ovo Vegetarian	Pescetarian
Meat (Red Meat & Poultry)	No	No	No
Fish & Seafood	No	No	Yes
Dairy Products	No	Yes	Yes
Eggs	No	Yes	Yes
Honey	No	Yes (Often)	Yes (Often)
Main Philosophy	Excludes all animal products	Plant-focused with dairy & eggs	Plant-focused with fish, dairy & eggs

Conclusion: Finding the Right Term

While the simple answer for an animal is "herbivore," the human equivalent is more complex. If someone is referring to a diet that includes only foods derived from plants, the correct term is vegan. However, many people who are often categorized as "eating only vegetables" are actually vegetarians, and consume animal byproducts like eggs or milk. The key is understanding that a complete plant-based diet extends far beyond just vegetables to include a full range of fruits, grains, legumes, nuts, and seeds. The most accurate name depends on the specific food exclusions and inclusions, highlighting the diverse nature of plant-focused eating.

Frequently Asked Questions

A vegan avoids all animal products and byproducts, including meat, dairy, eggs, and honey. A vegetarian excludes meat, poultry, and fish, but may still eat dairy products, eggs, or both.

No. A diet consisting exclusively of vegetables would be nutritionally inadequate and lead to severe deficiencies over time, as vegetables alone do not provide a complete spectrum of necessary vitamins, minerals, protein, and fats.

A herbivore is an animal whose diet consists exclusively of plants. While a vegan diet is plant-based, the term herbivore is a biological classification for animals, not for humans following a particular diet.

A fruitarian diet is a highly restrictive vegan diet that consists almost entirely of fruits, and sometimes nuts and seeds. Health experts caution against it due to the high risk of nutritional deficiencies.

Those following a vegan or strict plant-based diet should be mindful of their intake of vitamin B12, iron, calcium, and vitamin D, as these can be more challenging to get from plant-based sources alone.

A pescetarian is someone who follows a plant-based diet but also includes fish and seafood. They typically still consume dairy and eggs but avoid other animal meats.

Vegans can get enough protein by consuming a variety of plant-based sources throughout the day, such as legumes (beans, lentils), nuts, seeds, tofu, and other soy products.