It’s day six of your high-protein diet, and you can’t stomach the thought of another kielbasa-bacon-ham-olive-loaf-and-bologna omelet? Maybe it’s time to give those carbs another try. After all, marathon runners have long known that the best way to fuel up before a 26-mile race or a twelve-hour day at the office is with a heaping plate (or two) of pasta. Allan Steinfeld, president of the New York Road Runners Club and director of the New York City Marathon, gets his fix from Bella Luna (584 Columbus Avenue, near 89th Street; 212-877-2267), a friendly neighborhood trattoria with plenty of hearty pasta dishes. He likes Bella Luna’s “homey, low-key atmosphere,” which has earned the restaurant a loyal following among that dwindling Old Guard of Upper West Siders who prefer not to mix it up with the beautiful people at Spazzia and Ruby Foo’s on a nightly basis. “I like quiet places,” says Steinfeld. “My job is noisy enough.”