So I've decideded that being "authentic" doesn't mean you have to be "recklessly truthful" all the time.
For example, yesterday at the gym, one of the regular personal trainers came up to me and said, "Hey man, awesome work! I can tell you've bulked up and added size! How much more do you weight?" Now in all honesty, I've actually LOST weight in the last month. So, I didn't want to say "you're actually way off" so I just went along to make him feel a little better. I didn't want to throw his compliment back in his face, so instead I graciously accepted.
Authentically me :)