Dear Mr. XXXXX
I have been watching you on Channel XX for the past few months. I must say that I am very impressed with your weight loss. Of course, I don't know how much actual weight you've lost, but it looks like probably about 50 pounds [I've lost 60, but who's counting?]. Watching your progression has really given me some inspiration the last few months because I have lost about 30 pounds, myself.
You look great and I am very happy for you. I hope you'll drop me an email sometime. Maybe we can meet and discuss.
I have no intentions of calling her, although I may send a quick thank you email, but that was a nice little ego boost on my chair this morning.