This thread really illustrates the variability in body types - some people can eat what they want and maintain low/average body weights, others have to be strict, or can work out all the time and not lose.
I used to find this fact frustrating, but now I'm using it as a tool of acceptance. I have what I consider to be a confusing body - I am described by most as athletic/muscular, am 5'6" and weigh around 150, but wear a size 8 (when i read articles about people my height and weight, they describe wearing size 12 -something to be said for weight training!). I'd love to be around 125. But, there is just too much heterogeneity for me to sulk or beat myself up too much about the number on the scale. Its been a long tough road to get to this point (and I'm only 28, which means I'll travel it again and again I'm sure). Suffice it to say that there is likely always going to be a discrepancy between my "ideal" and reality, but I guess I'm just not willing to give up Cool Whip, cake, wine, and excellent restaurant food on occasion in order to see a number on the scale that probably won't last.