NEW YORK -- For more than a decade, Rafael Nadal has been viewed as one of the most physically fit players on tour. The 27-year-old Spaniard is 6-foot-1 of muscle.

After his 6-4, 6-2, 6-2 victory over Ryan Harrison on Monday at the U.S. Open, Nadal was asked if it was time to adopt a gluten-free diet. The 12-time Grand Slam champ panned the question.

"If you have the gluten-free diet or ... these kind of things that produce you not being happy the rest of the day, not being fresh mentally, that's a lot of effort for you," Nadal said. "Then you better don't do it."

While he acknowledges that gluten-free may work for some people, Nadal said each tennis player should cater to his own diet.

"There is not only one way to be a good tennis player or to be fit," he said. "Not all the players who had success in the history had the same diet or had the same style of play. Everybody's different."

Nadal is not even convinced gluten-free will be the top athletic diet in the next few years. The same way people believe Twitter and Facebook could be overtaken by the next social media site, Nadal says gluten-free dieting could lose its standing.

"Now, it seems like the gluten-free diet is great," he said. "After three years or four years, we will find another thing that will be great too. Then the gluten-free will not work anymore."

Nadal has his own routines for happiness and healthiness. In fact, Nadal does not think his methods are much different than those of his fans.

"I practice physical performance, practice tennis," he said. "I go fishing. I play golf. I go party when I have the chance to go party. That's all. I'm a really normal guy, normal life."

As part of being a normal guy, Nadal will not attack a gluten-free diet. Instead, he'll keep eating what makes him happy and what he believes makes him a world-class tennis player.

"I am happy with the normal diet," he said. "But I don’t say [gluten-free] is negative. I will say everybody's free to do what he wants. Everybody is not working the same things."

Nadal will not play his second round match until Thursday. He will be matched up against either Rogerio Dutra Silva of Brazil or Vasek Pospisil of Canada.

If Nadal wants to go eat a big steak in the meantime, he just might.