I'm wondering the same thing. There are times when I consume more protein than I need, so it's really been an exercise to start at the guidelines recommended by Phinney and Volek and adjust from there. I've found that I'm fine at lower levels, but I believe that also has to do with one's activity level. When I was running and playing hockey years ago, I'm sure I required more protein and consuming more protein wouldn't have made a difference with my weight. Today, my activity is frequent, but not as intense, so I try to stay lower. It's more of finding what works, since we all have differences in how we react. I'm still adjusting protein to learn how to optimize.