Understanding the Vegan Lifestyle: What does it mean when you only eat plants?

October 20, 2025 •

5 min read

Studies have shown that individuals following a vegan diet may benefit from a 15% lower risk of developing cancer compared to nonvegans. When you hear someone ask, "what does it mean when you only eat plants?" they are referring to the vegan diet, a practice that requires careful planning to ensure optimal nutrition and health.

Quick Summary

Eating exclusively plant-based foods, known as veganism, involves abstaining from all animal products including meat, dairy, eggs, and honey. This requires careful dietary planning to obtain all essential nutrients, often incorporating fortified foods and supplements for nutrients like vitamin B12.

Key Points

Veganism: Eating exclusively plant-based foods, avoiding all animal-derived products, including meat, dairy, eggs, and honey.
Not all plant-based diets are vegan: While vegan diets are entirely plant-based, other plant-based diets (like flexitarian) are more flexible and may occasionally include animal products.
Nutrient Planning is Crucial: Careful planning is required to ensure adequate intake of nutrients like Vitamin B12, Iron, Calcium, and Omega-3 fatty acids.
B12 Supplementation: Because Vitamin B12 is not naturally found in plant foods, regular supplementation or consumption of fortified foods is necessary for vegans.
Health Benefits: A well-planned vegan diet is linked to a lower risk of chronic diseases, including heart disease, type 2 diabetes, and certain cancers.
Potential Pitfalls: Unplanned vegan diets can be unhealthy, especially if they rely on processed vegan junk food, and can lead to nutrient deficiencies if not managed properly.
Focus on Whole Foods: For maximum health benefits, prioritize a diet rich in whole, minimally processed plant foods over highly processed vegan alternatives.

What is the Difference Between Vegan and Plant-Based?

While the phrase "eating only plants" most accurately describes a vegan diet, it's important to understand the nuance between a strictly vegan lifestyle and a more general plant-based approach. Veganism is a philosophy that seeks to exclude all forms of animal exploitation, which extends beyond diet to clothing and other products. A vegan diet is a subset of this lifestyle, strictly avoiding all animal-derived foods and ingredients. A broader plant-based diet, however, is a more flexible term that focuses on building meals around plant foods, but does not necessarily exclude all animal products. Some may follow a whole-foods, plant-based diet to maximize health benefits, while others might be flexitarian, meaning they eat a predominantly plant-based diet but occasionally include animal products. For someone eating only plants, the term is definitively vegan.

The Nutritional Breakdown of a Plant-Exclusive Diet

A well-planned vegan diet can provide all the necessary protein, fats, carbohydrates, vitamins, and minerals for optimal health. However, eliminating all animal products requires a conscious effort to replace key nutrients. Here is a breakdown of what to focus on:

Protein: Contrary to popular belief, it is easy to get enough protein on a vegan diet. Plant-based protein sources include lentils, chickpeas, beans, nuts, seeds, tofu, tempeh, and seitan. Soy products, quinoa, and amaranth seeds are considered complete proteins, containing all nine essential amino acids. A variety of plant proteins throughout the day is sufficient to meet requirements.
Vitamin B12: This is the one nutrient that poses the most significant challenge for vegans, as it is only found naturally in animal products. Deficiency can lead to nerve damage and anemia. Vegans must obtain B12 from fortified foods (such as fortified plant milks, cereals, and nutritional yeast) or, more reliably, from a vitamin B12 supplement.
Iron: The iron found in plant foods (non-heme iron) is not as readily absorbed as the heme iron from meat. However, vegans can increase iron absorption by pairing iron-rich plant foods with foods high in vitamin C. Good sources include lentils, chickpeas, dark green leafy vegetables, fortified cereals, and dried fruit.
Calcium and Vitamin D: These are essential for bone health. While dairy is a common source, vegans can get calcium from fortified plant milks and cereals, tofu set with calcium, sesame seeds, and leafy greens like kale. Vitamin D is produced by the body through sunlight exposure, but fortified foods and supplements are often necessary, especially during winter months.
Omega-3 Fatty Acids: Essential for heart health, omega-3s are primarily found in oily fish. Vegan sources include flaxseeds, chia seeds, walnuts, and canola oil. Algal oil supplements can also provide the long-chain omega-3s (EPA and DHA) found in fish.

Health Benefits of a Well-Planned Vegan Diet

When carefully managed, eating only plants offers numerous health benefits:

Improved Heart Health: Plant-based diets are naturally lower in saturated fat and cholesterol and higher in fiber, which can lead to lower blood pressure and LDL ("bad") cholesterol levels, reducing the risk of heart disease.
Weight Management: Vegans tend to have a lower Body Mass Index (BMI) compared to nonvegans, potentially due to higher fiber intake and lower caloric density of plant foods.
Reduced Chronic Disease Risk: Studies show a link between plant-based diets and a lower risk of developing type 2 diabetes and certain cancers, including colorectal and prostate cancer.
Enhanced Digestive Health: High fiber intake from plant foods supports a healthy gut microbiome and regular digestion.

The Risks of a Poorly Executed Vegan Diet

It is a misconception that all vegan diets are inherently healthy. The healthfulness depends on the food choices made. A diet of only vegan junk food (e.g., refined carbs, processed meat substitutes, and sugary desserts) can be high in sodium, additives, and unhealthy fats, offsetting potential benefits. A poorly planned vegan diet also carries a high risk of nutritional deficiencies, particularly for Vitamin B12, but also potentially affecting iron, calcium, and zinc levels. These deficiencies can lead to serious health issues, including anemia, neurological problems, and bone health issues. For vulnerable populations like children and pregnant women, careful planning and supplementation are even more critical.

Comparison Table: Strict Vegan vs. Whole-Food Plant-Based


Feature	Strict Vegan Diet	Whole-Food Plant-Based Diet
Animal Products	Excludes all animal products (meat, dairy, eggs, honey).	Focuses primarily on plants but may occasionally include small amounts of animal products.
Processing Level	Can include processed vegan foods (e.g., meat substitutes, packaged snacks).	Emphasizes whole, minimally processed plant foods like fruits, vegetables, legumes, and grains.
Primary Motivation	Often driven by ethical, environmental, or health concerns.	Primarily motivated by a desire for improved health.
Nutrient Management	Conscious planning and supplementation (especially B12) are essential for nutritional adequacy.	Careful planning is still important, but small amounts of animal products can help with certain nutrients.

Practical Steps for Eating Only Plants

If you are transitioning to an exclusively plant-based diet, here are some steps to ensure success:

Gradual Transition: Start by incorporating more plant-based meals into your routine before making a complete switch. This helps your palate and digestive system adjust.
Educate Yourself: Learn about balanced vegan nutrition, focusing on reliable sources of protein, vitamins, and minerals. Understanding which foods are fortified can be particularly helpful.
Diversify Your Plate: Eat a wide variety of fruits, vegetables, legumes, whole grains, nuts, and seeds. This ensures a broader range of nutrients and amino acids.
Prioritize Whole Foods: While vegan junk food exists, focus on whole, minimally processed plant-based foods for optimal health benefits.
Plan for Key Nutrients: Pay special attention to Vitamin B12, Iron, Calcium, Vitamin D, and Omega-3s. Use fortified foods and consider supplements as needed.
Consult a Professional: Speaking with a registered dietitian can be beneficial, especially if you have existing health conditions, or for special life stages like pregnancy.

Conclusion

So, what does it mean when you only eat plants? It means following a vegan diet, a conscious decision with significant health, ethical, and environmental implications. A well-planned, whole-foods vegan diet can provide numerous benefits, including a lower risk of chronic diseases and improved heart health. However, without proper planning, it carries risks of nutritional deficiencies. By understanding the nutritional requirements and incorporating a variety of whole plant foods, fortified products, and supplements where necessary, a vegan lifestyle can be a healthy and fulfilling choice for many individuals across all life stages.

Frequently Asked Questions

No, while both diets avoid meat, a vegan diet (eating only plants) is stricter. Vegetarians may still consume animal by-products like dairy and eggs, whereas vegans exclude all animal-derived products.

Yes, it is entirely possible to get sufficient protein from a plant-only diet. Good sources include legumes (lentils, beans), nuts, seeds, and soy products like tofu and tempeh.

The most common and significant nutrient deficiency risk for those eating only plants is Vitamin B12, which is almost exclusively found in animal products. Supplementation is therefore essential.

Yes, to prevent a Vitamin B12 deficiency, supplements are necessary for anyone exclusively eating plants. Depending on your diet and sun exposure, supplements for Vitamin D, Iodine, and Omega-3s may also be advisable.

Not automatically. The healthfulness of a vegan diet depends on the food choices. A diet consisting of highly processed vegan junk foods can be unhealthy, while one focused on whole plant foods provides many health benefits.

Vegans can get calcium from fortified plant milks and cereals, tofu set with calcium, leafy greens like kale and broccoli, and sesame seeds.

Plant-based iron sources include lentils, chickpeas, dark leafy greens (like spinach and kale), fortified cereals, and dried fruits. Pairing these with Vitamin C-rich foods enhances absorption.

Yes, a well-planned vegan diet can be appropriate for all stages of life, including childhood and pregnancy, but it is especially important to ensure adequate nutrients like B12, D, and iron, often through supplements. Consulting a health professional is highly recommended.