Clinical studies have not proved it's just fine, and the carbs that are re-introduced are still too low to fuel many vital functions in the body. That is the opinion of almost all the scientists who specialize in diet as it relates to health and fitness. As far as the clinical studies, they are all short term and they only address weight loss and overall cholesterol. Just about any diet can help you lose weight if you stick to it (And don't forget exercise). Cholesterol is one of the most misunderstood concepts in nutrition. Short term adjustments don't equate to better health. There are also 2 new studies (one in the US and one in the UK) that studied close to 700,000 people over the course of several years. The study concluded that people who consumed large amounts of fiber, specifically from grains and fruit (almost forbidden on Atkins) and not from vegetables, reduce their risk of colorectal cancer by 36%. The amounts of fiber are well above what would be allowed on Atkins. I'm not looking for an argument here, but many people are jumping on this bandwagon based on some very limited information. The vast majority of research (which doesn't get the same media exposure) suggests that Atkins is not healthy.