Fad diets are usually caused by one particular person making up some random rule about diets and it worked for them and only their body type. usually "Fad diets" are meant to be a temporary thing but as soon as you come off the diet you will find that your body will gain weight and possibly more than what you have started with. This is because if you gave up sugar for example then as soon as you came off the diet went back to consuming bucket loads of sugar your body won't know how to react, turning the extra sugar into fat. therefor "Fad Diets" don't actually work.
