For most people, if you go less than 1500 calories you will have to do it for the rest of your life, otherwise the weight will go back on when you stop. This is an unfortunate but unavoidable fact!!! It is a fact that lots of kids here and people everywhere are in denial about but it is true! That is why it is known scientifically that diets do not work. Permanent change of lifestyle works with regular exercise and a sensible LOW-FAT eating plan. Learning to know when you have eaten enough and eating a wide range of low fat food. An eating plan which is flexible and you can stick to it forever and it will protect your health as well as make you slim. I can see lots of kids here who are desperate to be slim, but this is the ONLY way to STAY slim once you get there!!! GOOD LUCK!!!!!!!!