My doctor is thrilled. I had a complete blood workup three months into this, one year after lab tests that showed me as borderline diabetic, high cholesterol (for which they wanted to put me on Provochol, I think), and blood pressure in the range that would put me on medication in a year. When doing the second set of lab tests, he really didn't think my cholesterol would be down. When I got my results in the mail, he had written "TERRIFIC!" on the page. All my test results were just that, terrific.
There is no doubt that the Atkins diet, strictly adhered to, will take off weight rapidly, at least in the short run. And there's no doubt that taking off a quick 20, 30, or 40 pounds (if you need to) will make you feel better.
I have lost 40 pounds in one year (technically, 8 months and a four month plateau). Best case, that's 1.15 pounds a week; worst case, that's .77 pounds a week. I would not count it as being "rapid" except for the beginning, where I did drop 8 pounds in two weeks. Everything else has been very steady, with lots of mini-plateaus to work through.
Before this, the most I had ever been able to lose was 25 pounds, and that was on Redux for two months and walking four miles a day on my lunch hour...a medication that was pulled because people died on it, and time I simply do not have to put toward exercise. I liked doing the Redux, because I didn't think about food all the time. Atkins is the same: I don't think about food all the time, because I am satisfied on what I am eating.
But you're playing with fire (in my confessedly uninformed opinion) if you make Atkins your permanent diet.
In my very personal experience, if I eat the USDA food pyramid, I will have the following symptoms: bloating, gas, irritable bowel syndrome, cravings for more starches that I CANNOT ignore, no energy, constant fatigue, high blood sugar, diabetes, and pounds, pounds, pounds. For me, and many others like me (not everyone, I agree), THAT kind of permanent diet -- as in American Heart Association, American Diabetes Association -- isn't living. It's a chronic crappy day mixed with Lane Bryant fashions.
I appreciate your concern. I may point out, though, from your other post, that the reason Atkins folks defend their way of eating so vigorously is that we keep getting told we're crazy, deluded, losing water (uh...40 pounds of water?), and GOING TO DIE SOON. So yes, we're a little defensive. And thinner. ;-)
Why are so any poor people fat? Because they eat a diet that is largely starch: bread, potatoes, pasta, and other cheap "filler" foods. That stuff turns straight to fat. Our pre-agricultural ancestors did not eat Kraft Macaroni 'n' Cheese; they ate wild greens, wild fruit, fish, insects, and (when they could get it) game. That's the "natural" diet for the human being if there is any such thing.
Again: One should never go on any kind of diet without the advice and consent of one's own M.D.