The medical community has had a lot of criticisms of low carb diets as being dangerous to your health in the long term. Not all low carb diets are the same, but this web stie will give you an idea of some of the problems:
Atkins Facts - Atkins "Nightmare" Diet
Dr. Dean Ornish's book "Eat More, Weigh Less" is similar to his plan for reversal of heart disease ( clinically verified ) and has been show to work.
Good Luck