I discovered low carb (ketogenic) dieting the hard way.
It started about ten years ago, when I decided to get in the best shape of my life (in terms of body composition).
I joined a well known amateur fitness competition, which involved sending "before and after" pictures.
I trained hard and ate a low-fat diet--I never cheated.
I thought this would turn me into a super-lean machine.
Well, I did lose fat, but there were problems:

• I did not get as lean as I thought I would--especially considering the discipline I had with my diet/exercise.
  
• I lost too much muscle mass.
  
• I was constantly fighting hunger.
  

Years before I had heard about a "high fat" diet, but I never paid much attention to it (sounded crazy to me).
 I was ready to give it a second look.
 I did some research and ran across some good articles.
 I read about the Body Opus diet, the Anabolic Diet, and a few others.
 These diets/books were more for bodybuilders (I roughly fit into this category, though I don't compete).
 I also read a few websites written by those using the Adkins diet.
I remember one guy who used to weigh 300 lb until he tried low carb approaches.
  Now I'm a low-carb fan.
 I drop carbs whenever I want to get lean.
 Here are some of the benefits I've seen:

• I retain almost all of my muscle and strength, even on a calorie restricted diet.
  
• Hunger is not nearly as much of a problem.
  
• I'm not as tempted to cheat.
   This sounds crazy, but knowing that I can't eat any carbs keeps me from eating junk--I know that eating too many carbs will break ketosis.
  *
• I get leaner, faster than with any other approach.
  

If you haven't had results with other approaches, consider giving low carb a try (assuming you are healthy or have checked with your doctor).
 I'll try to write a few more articles as I have time, but there's no shortage of information out there.
  *Ketosis is a state in which your body is primarily using fat (body fat and dietary fat) as fuel.