Comment by axb

I'm a long term vegan and I've never had to supplement. Plus 80g is on the high end, though obviously it depends on activity level.

The CDC recommends 56g daily for males 19 and up. Out of your daily calories somewhere between 10-35% should be from protein. http://www.cdc.gov/nutrition/everyone/basics/protein.html

That being said, you're correct that it isn't good to rely on one source of protein.