The only other Surgeon General I can even remember was C. Everett Koop and he looked like he was carrying a 50 lb. flour sack under his shirt. Believe me he's taken down a number of Super Size meals at McDonalds in his lifetime.
There's no reason Dr Benjamin should be held to any higher standard than the Koopster.
And she's done some very good things in her lifetime to help others that she didn't have to do. Obama seems to have picked a fine candidate for this job.