Cons of a Plant-Based Diet Potential Nutrient Deficiencies: Vegetarian and vegan diets need to pay extra attention to ensure they're getting enough protein, calcium, iron, and vitamin B12 in their diets.

One of the primary reasons people quit veganism is health concerns. While veganism can be a healthy and sustainable diet when done correctly. Some individuals may experience inadequate nutrition and deficiencies due to a lack of knowledge about plant-based sources of essential nutrients.

While there is some scientific research to suggest that going vegan and eating less animal protein can help to prevent diseases, the evidence is still lacking in terms of cold, hard numbers on longevity in particular. However, this doesn't mean that a vegan diet won't help you live longer.