Hi Flex, I have eaten the Atkins way for over 15 years and would never consider any other way. The reason why most people fail at this plan is because they don't know what they are doing, or they allow carbs to creep into their diet and for Jadensmommy's friend, you are not supposed to come off it, if she was doing it right she would have moved into maintenance and be eating a very healthy diet now. Atkins is a lifetime committment, not just a flash in the pan quick fix for a few pounds. Your friend can be assured that if she adds a few grams of carbs to her diet every week, 10g per week, she will not regain weight. Any weight that goes with the extra 10g is water not fat and she will lose this quickly if she keeps her water balanced.
Atkins is not an unhealthy plan, don't let anyone put you off by telling you they felt ill, they were tired, they couldn't do without their sugar fixes.
Feeling ill for a couple of days at first is a good thing, it means that you are detoxing from all the crap your body has stored. It even has a name - Atkins flu. Everyone who does the diet properly knows about it and prepares for it and handles it. When ketosis kicks in at about day 3 or 4 you feel great, your energy levels soar, and your head clears. This stage means that your carb stores are empty and you are burning fat. You also lose your sweet tooth and cravings. The restricted stage only lasts 2 weeks and this is to get you into ketosis. After the first 2 weeks you can move onto ongoing weight loss and gradually add good carbs (if there ever was such a thing) back into the diet, or you can continue at induction for as long as you feel comfortable.
Don't be put off by those who say you will have a heart attack or your cholesterol will soar, it won't, in fact it will fall quite dramatically after a couple of months, particularly your triglycerides. If you are diabetic you will be able to reduce and eventually come off meds (not insulin boviously if you are type 1).
My first piece of advice: READ THE BOOK. You can't do the diet without the book but there are great sites out there to give you support.