Does anyone have an opinion about the Medifast Diet, does it seems to work and can you keep your weight off once you are off of the program?

This interests me as well.

I did the medifast diet about 6 years ago for a month and lost around 20 lbs, but if you don't keep up with a low carb lifestyle you will definitely gain it back pretty quickly. For maintenance medifast suggests you use their products and fast every once in a while.