I also have a theory(and I could be wrong here) that hes behind her taking the exercise so seriously...I'd say hes strict enough in that field that he pushes her to get the steps and workouts in ..he wouldnt have a wife that likes to lounge around....
A friend of mine married her PT and he is exactly like you describe. I think they are both as bad as one another (Niamh and TJ that is) but I say there is definitely an element of having to be mad into fitness and nutrition.
Like we knew if we visit our friends house to never bring cake, chocs or biscuits etc. It is always healthy stuff as he doesnt allow them in the house. If any one brings junk food or sweets etc she brings them to work the next day.