By Zoran Milosavljevic

BELGRADE (Reuters) - A change of diet has played a major role in Novak Djokovic's unbeaten run this year, the world number two said Monday after receiving a hero's welcome from fans in his home town.

"His name is Igor Cetojevic, he is a nutritionist and he's done a great job in changing my diet after we established I am allergic to some food ingredients like gluten," Djokovic told reporters on the opening day of the Serbia Open.

"It means I can't eat stuff like pizza, pasta and bread. I have lost some weight but it's only helped me because my movement is much sharper now and I feel great physically.

"A lot of people have been guessing and speculating what the secret formula of my good form was but there is no secret, it's just that all the pieces have fallen into place after years of hard work and we are now reaping the rewards," added Djokovic.

The Serb paid tribute to his entire support staff, saying it was their hard work that had made him the player he is.

"I have a great team of people around me," he said. "I have unreserved faith in their instructions and trust them completely.

"I have also matured as a player and a person. I feel more confident and more consistent than ever because I am capable of holding my own against the world's best players under any circumstances.

"That wasn't the case earlier ... whenever I needed to be consistent against (Roger) Federer and (Rafa) Nadal in the latter stages of grand slam events I was unable to stay psychologically balanced and confident."


He had photos taken and signed dozens of autographs as the crowd greeted one of Serbia's most popular public figures.

"The Serbia Open will always have a special place in my heart because we rarely get a chance to play in front of our own people, it's only this tournament and the Davis Cup," said Djokovic.

"That's why I expect them to turn up on center court to watch all Serbian players taking part in the tournament, which is getting stronger and more competitive every year.

"I had to retire very early in last year's event because I was unfit but I feel very well now and I am looking forward to my first match Wednesday."

His first red clay event of the season could be the springboard which helps him dethrone world number one Nadal.

"Down the years as Nadal kept ripping apart everything in front of him on red clay, we always thought there was no room left for improvement in his game and he kept surprising us every time," Djokovic said.

"He is still the player to beat on red clay and the favorite in each of the upcoming major events, including the French Open, because he is so dominant on this surface.

"However, I am playing with a lot more confidence against him these days and I now believe I can beat anyone on any surface, although beating Nadal on clay remains a big ask and the biggest challenge of all."

"I needed the extra two weeks of rest to recover from a grueling hardcourt season, a surface which is not very pleasant for knees and tendons, but I am ready now," the Serb said.

(Editing by Tony Jimenez. To query or comment on this story email sportsfeedback@thomsonreuters.com)