How does the Zone compare/contrast to the South Beach Diet?

At the basis of the Zone diet is maintaining stable blood sugar (the absence spikes and drops) which results in better hormonal control, better energy levels and better inflammaton lowering than you are likley to achieve with South Beach. In addition, the Zone doesn't have stages or phases. From day one of the Zone diet you'll be eating the same way for as long as you decide to follow Zone principles.

Ayesha,

I recall reading about the SBD at one time. It starts out similar to Atkins, and then it progresses up similar to the Zone. The idea behind it is similar to the Zone in terms of carb control.

Yes, the 2nd phase of South Beach is somewhat Zone-like but lacking consistency re balance, which results in inconsistent hormonal control. With the third phase, it all goes out the window because you're basically told that now you know what to do and you're on your own. You're also instructed that when you begin to gain weight (which IMHO is inevitable due to lack of guidance at that point) all you need to do is go back and repeat phases 1 (Atkins - like) and 2 (Zone -like). Sounds a lot like yo-yo dieting.