There are plenty of fad diets out there, and frankly a lot of people like to use them to lose weight even though they are not healthy.  They incorporate certain methods of action, and some people don’t use fad diets but actually do it by themselves.  Frankly, sometimes it falls into the category of eating disorders which actually may include too much exercise to the point of throwing up on a regular basis(one time is not really made to classify you as bulimic or otherwise), eating too little, or eating nothing at all except on occasional binges. 

But starvation of course is the most effective, yet one of the worst ways to lose weight.  Likewise, using diuretics to lose water weight or other methods to again lose water weight means it will all come back extremely quickly and it doesn’t work at all the way you want it to.  Likewise, excessive exercise doesn’t work.  Cutting out an entire food group as you would find in fad diets is not good, or for that matter limiting it to one food or one food group is really not a good way to go. 

Purging is of course not the way to go, and finally you don’t want to go under the knife.  It has become a popular decision because people think it’s the easy way out.  But frankly, its complications are extremely severe during and far after.