Carnivore diets can be healthy, and vegan diets can be unhealthy. The overall influence of the diet on your health is not defined by its name, but by the mix of foods within the diet as well as cooking methods.
I am a strong proponent of a plant-rich diet, as opposed to entirely plant-based. Eat more vegetables and less starches (potatoes, rice), whole grains, fruits in moderation (high fructose may cause non-alcoholic fatty liver).
Ensure you get a variety of vegetables every time, mix colors, and cooked and raw foods. Use healthy cooking methods to preserve the most nutrients and choose food coming from organic farms to avoid toxins.
But vegan is often an ethical choice rather than a health one. So if you are determined to go vegan, please, make sure you know where to get all of your nutrients from. Else, you will fall sick, and won’t be of any help neither to animals, nor to the planet.