but it isn't sustainable or healthful for
> longer than a few months in my experience.
>
> Jana

Some do better than others. Cultures where vegetarianism is common
develop special foods to try to replace the missing nutrients. I think
for adults this is possible. Most vegetarian cultures are not really.
The Japanese for example have some religious sects that are
vegetarian, but they make exceptions for so many things, that they get
a trickle of animal products all the time. In fact they seem to
consider fish vegetables.