Another one who envies MM.
I started off being very thin up until I reached "ahem" middle age and had my back operation, from then on I am now larger...

It doesn't help that I love my food.

One of my very good friends has just been to the dietician at the hospital. She eats very carefully, goes to the gym but cannot lose weight (she isn't very overweight to me but wanted to do it partly for health reasons) Basically they have just told her that they don't know why she isn't loosing weight, she is doing everything right so thats that!
My poor hubby is another one who has struggled with his weight all his life, the only time he really lost any was when he went on those diet drinks they used to have in the early 80's. Of course as soon as he stopped them it all went back on and more. I think there can be a definite genetic link with some people and yes I do know that isn't everyone but some lucky people are what we call the "Greyhound" breed.
At least by trying to eat healthily (apart from bearclaws..

) and going to the gym sometimes you have to accept what you are...