Who is Dr. Peter Krushlevensky from Good in Bed and what is their importance?

Dr. Peter runs the weight loss program Cannie joins in order to lose weight. He is physically described as tall an handsome, as a man, he is described as respectful, courteous, and compassionate. Interested in Cannie romatically, Dr. Peter respects her need to heal and guides her through difficult times before the two ever become romantically involved.