I have seen a documentary the other day about vegans.
While some aspects seems appealing, it seems that you have to be really cautious about getting enough vitamins that you naturally get from meat. That's too much of a hassle for me.
Well, it's a false deficiency perception.
Like 'normal' diets, you have folks that eat very poorly (junk food, too much filler, sugar, etc.).
Vegans I've known have mainly been uber health focused. Think diverse eating and lots of veg, juicing, actual food preparation, etc.
Vitamin and nutrient deficiency is an epidemic in the US, even though lousy animal feed most eat is 'fortified'. Read they dump mainly waste byproduct into food stuffs to add nutrients since the core ingredients are cheap, inferior and waste streams suitable for animal food in fattening farms rather than humans.
That said, there is a B vitamin or two absent in a vegan diet.
Benefits of vegan diet when done in conjunction with properly grown veg and fruits is pretty superior though.
Regardless of which diet you adhere to in the "industrialized nations" you need to be on nutrition supplementation. Humans like all animals eat for nutrition, not for stomach fullness. Problem is lying arse mega corps have messed eating all up. Turned it into another entertainment experience and stripped all understanding and education from it.
A hungry stomach is not an indication of a lack of food unless you haven't eaten. If you eat and need to always eat more, odds are you are eating food that is lacking nutrients. Plants can grown with three main nutrients N-P-K. Doesn't mean they grow complete or properly. Means to your eyeballs they look alright.
Since farmers don't grow these days on glacial washed and spring flooded valleys, there isn't any nutrition (well VERY little traces at best) in most fields. That's why they N-P-K dump on fields in the spring. They may dump powdered lime also... Beyond that, average farm isn't bringing in nutrient pools for the batch of crops.
Therefore what you and the geniuses in government think is the nutrient breakdown of a tomato is very different from what you are actually buying in the average market. I am constantly surprised at how many folks hate vegetables and are amazed at what such actually tastes like when grown in a better way.