Paris - Novak Djokovic refused again on Wednesday to divulge the secrets of his French Open super-diet, comparing constant questions on the subject to being quizzed about his sex life.Serb second seed Djokovic has given up bread and pasta after developing an allergy to gluten, but he will not reveal what he eats instead."Because it's private. There are some things I can speak about; there are some things I can't," he said."I can tell you who is my girlfriend, but I cannot tell you what I do with my girlfriend. This is a difference."Djokovic reached the last 32 on Wednesday when Romania's Victor Hanescu was forced to retire from their second-round tie with a left thigh injury.Djokovic was leading 6-4, 6-1, 2-3 when Hanescu called it quits.The Serb will face Argentina's Juan Martin del Potro for a place in the last 16.