It's nothing new. There are a ton
of diet books out there based on the Glycemic Index. The Montignac Method
(republished & retitled as The French Diet
recently), Sugar Busters!
, The New Glucose Revolution
, The GI Diet
, Good Carbs/Bad Carbs
, just to name a few. Heck, even Somersizing & South Beach incorporate the Glycemic Index to an extent!
A lot of them you can find in used bookstores or as paperbacks new; probably a lot cheaper than the newest thing.
It works, in no small part, because it forces you to stop eating junk food. The GI isn't a magic system, IMO, but it will
help you feel full longer & therefore you'll wind up eating less over the course of a day. And if you keep the emphasis on whole foods, you'll wind up healthier as well. Do a Google search on the Glycemic Index; I know there's a searchable one online, but I'm not 100% sure where. Low GI foods are anything with a level of 50 or below.