No diet really works. <br />
They are just a way to make money by selling pills or books. If you come across a diet that you don't need a book for, there usually still is a book about it and you are supposed to buy it. <br />
If there was a diet that actually worked, the news would spread like wildfire around the globe! Eating the right stuff at the right time and working out the right amount every day, that will do the trick, but needs a whole lot of discipline and work. Most people don't have that, which is why they look for the magical diet that does it for them -- hence all the books and pills.
Yes, they make sellers of these diets richer.
No, they are very poor choices for those who want to be beautiful and healthy. You need to change your eating habits to loose weight consistently and if you want to be beautiful and healthy you need to start a routine of exercises. There is no easy or fast way to do it. Just the one hard right and all the wrong fast ways.
No, but do some research on low carb diets.
No, only self decipline works