I whole-heartedly agree with the comments of almost_n_s.
I've put on weight since starting running but I look slimmer and I can tell when I put my jeans on that I'm losing a bit around my stomach.
I'm also getting fitter which feels great. Its nice to have the extra energy that I'm getting and also its nice to get into bed and feel genuinely physically tired.
I think the key is sticking at it long enough to get the 'bug'.. I'm getting there I think.
I still find it hard to drag myself out on a run but I feel brilliant once I've finished.
As for dieting. I think doing some exercise gives you a much greater freedom when it comes to foods. I quite like having the odd chocolate or meal out and don't feel guilty because I know that I'm exercising as well.
I would guess that the more you exercise, the fitter you become and the longer you can exercise for.. so I would assume that the weight will come off faster and faster as time goes on and you get fitter... at least that's what I'm hoping
