Is a vegan diet healthy?
The word “vegan” just means the exclusion of animal products (meat, fish, dairy products, eggs). It is true that the consumption of animal products increases the prevalence of chronic illnesses. However, when animal products are given up and yet unhealthy vegan products are selected instead (highly processed and/or fried items) then the advantages of a vegan diet are rendered almost void.
A vegan diet in which one drinks lemonade and eats chips and a seitan burger is very unhealthy and associated with many deficiencies.
To summarize, in order to be able to say whether or not a vegan diet is healthy, we need to know much more detail about the diet!