I lost 5 stone in 14 months. At over 5'9" I'm just about bang on 13 stone. I've made huge progress in my cycling, but climbing is the weakest part, and has let me down several times. I've improved it substantially, but its still my worst area and I'm still some way off the people I want to compete with. I'm gradually, albeit reluctantly coming to the realisation that I'm still at least a stone and a half over where I need to be.
Climbing is all about watts per kilo, and the good climbers are all pretty thin by what are seen as todays standards. Part of that is that being fat has become the norm. Look at photos from the 50's and 60's to see how much body shape has changed and how that has altered our perceptions.
Sorry if that is not what you want to hear. A year ago when I stopped losing weight I certanly wouldn't have wanted to hear it. At that point I was still very proud of what I had achieved, and my friends and family were making noises that I had gone far enough. The bike took over as an incentive rather than losing weight and my weight has been stable for over a year now. I have gradually come to the conclusion though that to achieve my goals in cycling I will need to lose more.