I am a nutrition honours degree student and i urge you all who have this habit to stop it because you are not skipping calories in this way. You begin to absorb the energy from the food as soon as it is placed in ur mouth, whether you go on to spit it out or not. It is ineffective, ultimately makes you put on weight, makes you obsessive and moody and makes your face and salivary glands swell up so you look like a hamster. I know, because i used to do it. Now i want to help you all who share this disorder to see it simply won't work- thats what helped me quit.