no- you don't have to be on it forever- you can eat a little bit of carbs after the first two weeks and you add them slowly into your diet again. it's not unlike any other diet in that you can't eat everything that made you gain weight before because obviously you'll gain weight. it's only bad for your kidneys if you keep on it for too long becasue your kidneys will be making ketones for your body to run on instead of sugar which is stored in your kidney. for every 1 pound of fat stored in your kidney there is 6 pounds of water! you lose that during the atkins diet. and again with the bad breath- that's due to ketonosis also- but it shouldn't become that extreme...