I reckon a stone is 6.35 kg. so before we start off with plans with easy and/or not so easy tips... lets look at a theoretical view on which diet or plan you might want to use. so i found this in a book i read some time back. the following are percentages of fat loss you're likely to archive on different diets...

-VIRTUALLY STARVING YOURSELF = less than 30% fat loss-VERY LOW CALORIE DIET= less than 50%-HIGH PROTEIN DIET=40-60% -SOUTH BEACH DIET (no carbs diet)=40-60%-ATKINS DIET=40-60% -LOW FAT DIET= more than 60% fat lossCALORIE CONTROLLED DIET= up to 70% fat loss.

Healthy Balanced Diet With Gradual Reduction In calories and gradual increase in both duration and intensity of exercise = 90% plus weight loss

When you're thinking of losing weight, use the tape measure more than the scale as followin the scale will tempt u to try drastic measures that will only make you lose your muscle and water weight which is not good for you. What you're trying to lose is eat weight. If you're starting yourself or throwin up after a meal, then you'll gain the weight back after a while.