New Djokovic book: Gluten-free diet

Novak Djokovic attributes his success in recent years to a change to a gluten-free diet. Now he'll be sharing his nutrition tips in a book called "Serve to Win," which will be released before the U.S. Open.

Novak Djokovic attributes his success in recent years to a change of diet. Now he'll be sharing his nutrition tips in a book to be released before the US Open.

''Serve to Win: The 14-Day Gluten-Free Plan for Physical and Mental Excellence'' ($25, Zinc Ink/Random House) is the title of Djokovic's ''nutrition-based performance guide'' that is to be published next month.

The top-ranked Serbian has won six of his seven Grand Slam tournament championships since adopting a "performance-focused" gluten-free diet in late 2010. In 2011, he took the Australian Open, Wimbledon and the US Open. He has since won two more Australian Opens.

Djokovic says "finding the right foods for my body has made me lighter, healthier, and more focused." He adds that "it's made all the difference in my career and in my life."