ummm I can not remember but there were several documentaries that shows that people who lives long time eats meat several times a week!
I think their diets are balanced by eating fish, veges and meat.
Often japanese people stop eating meat when they get old, but the survey showed that old people who lives long loves eating meat.

I believe that only eating meat is not good.
So only eating meat everyday is not a key to live long.

There are several opinions, yet that's how they found out when they took survey to people who are actually living long and healthy. I will let you know when I found out the name of documentaries :)