Mike, if you weigh 15 stone then you actually need 3360 cals to maintain weight. Are you eating the right stuff and keeping your metabolism high? By eating less and starving yourself you can actually suppress your metabolism so that when you do eat, your body stores it as fat because it doesn't know when you might eat again. Small and regular is the key. Just knock off 500 cals from the above figure and then split it into 5-6 meals over the day.

Paul.