Markevans999 is right. Dr. Barry Sears is a Ph.D nutritionist from MIT. No complications have been reported with his diet unlike Atkins which has many case reports of kidney stone formation, gallstone formation, interstitial nephritis etc. I know alot of medical doctors at the teaching institution here who recommend the Zone but very few recommend the Atkins (even though he is a collegue, a fellow Md!)
And as Supcom so elegantly and succinctly stated:
Ride your bike more. Eat less. Eat smart. It's more fun than surgery.