I think it is important for you to ask yourself why. I 100% believe that vegan is a great thing but I’d have to know why you are under weight. Personally, I struggled with an eating disorder & my veganism helped me hide it. Of course, this is nothing against vegan Islam & real vegan Ian is not a diet. However it can be extremely harmful if you are currently struggling with food. I am currently in recovery & eat mostly vegan but am temporary incorporating poultry and products that may contain animal products. My family always buys local when we buy our poultry & I still avoid palm oil. Do what is best for you