I have a very dear friend who was on the the Atkins for three years. He lost 40 pounds and maintained it. But when he went off of it, he gained back most of it.
he was completely healthy while on the diet. his blood work was fine. he loved the atkins bars. they are expensive but very filling. he ate a lot of meat and very few carbs.
his favorite bars are the chocolate decadence bars. they are pretty good.