I agree that it is the TYPE of weight you carry and if your doctor tells you to loose weight then you have a problem.
On the flipside, I was always thin. I am just a petite person (5'3") with small bones and a high metabolism. Anyone who knows me well knows this. However, there are always the concerned people looking out for me. I can't tell you the number of times I found pamphlets on eating disorders stuffed in my purse or in a book. I used to get really offended but then I realized that they just didn't know any better.