vegans or vegetarians could get sick from their diet but not necessarily from not eating meat.
the whole protein thing is so blown out of proportion. ALL veggies, grains, nuts, and seeds contain protein and as long as a person gets enough calories, they get enough protein.
people get sick on a diet when they eat crap....snack foods, donuts, cake, pies, cookies, chips, soda, lots of fruit juices, etc. EVERYONE needs friuts veggies, lean protein sources and whole grains,no matter what kind of diet they are on.