When the wildly popular Dave Matthews Band takes to the stage Tuesday night at the Nikon at Jones Beach Theater, one might imagine that such a high-energy, big-arena entourage would be fueled by fast food, junk food and late-night bingeing.

But the band and crew will have just eaten clams dug out of Long Island Sound that morning, veggies plucked fresh from farms in Amagansett and Cutchogue and ripe berries off the vine in Riverhead.

DMB has been eating in this farm-to-stage way for 20 years. That’s because Dave Matthews is dedicated to local, sustainable food and cares deeply about farmers and their crops.

Several years ago, Matthews partnered with Reverb, a grass roots outreach and education program, to encourage concertgoers to become more environmentally aware. Reverb works with touring bands, creating backstage greening programs with the aim of reducing the overall environmental impact of their tour.

Their program connects local farmers and food artisans to tour chefs. Matthews’ vision is fueled on the tour circuit by Dega Catering, a full-service concert tour caterer that has been feeding DMB like family for nearly two decades. Its assertion that “homemade food is one of the few comforts that you can enjoy on the road,” has afforded Dega an all-star touring client list: DMB, Bob Dylan, Keith Urban, Lady Antebellum, Usher.

Dega, with the help of Reverb’s ever-expanding database of local farms, sources all its food provisions locally. On Long Island, Dega has an established relationship with Jeff and Emer Moore of Rustic Roots Delivery, an organic food home delivery service based on the East End.

Rustic Roots has an extensive working relationship with farmers, fishermen and artisanal purveyors throughout Long Island and upstate New York.

Dega’s DMB tour chef, Rob White, contacts Rustic Roots several days before the Jones Beach show, seeking a list of what produce would be at peak ripeness on the day of the show. “Two days before show day is when Rustic Roots would get my final wish list, ensuring that everything is harvested the day before, or even the early morning of the show,” White says.

Rustic Roots will then spring into action, gathering kale, arugula and lettuces from Balsam Farms in Amagansett, sprouts from Koppert Cress in Cutchogue, fruit and berries from Briermere Farms in Riverhead and fresh-off-the-boat seafood from Cor-J Seafood in Hampton Bays. Beef, pork and poultry orders are placed a few days ahead of time with longtime Dega supplier Suburbia Prime Meats of Merrick. “Everything is delivered fresh, never previously frozen,” says White. This year, littleneck clams, which were to be dug out of Long Island Sound on the morning of the show, will tweak Dega’s menu riff from farm-to-stage to Sound-to-stage.

On performance day at Jones Beach, Dega’s team will prepare and serve breakfast, lunch and dinner in a mobile pop-up kitchen behind the stage for 110 to 250 people: band members, crew, local crew, friends and family. Everything is served family style on ceramic Fiestaware plates with stainless steel cutlery. Detailed menus are posted, giving credit and thanking the farmers, fishermen and purveyors for their work. One of the culinary highlights at the Jones Beach show is the homemade lasagna made by production manager Anthony Giordano’s mother and delivered in pans from her Babylon kitchen to backstage.

Some might ask themselves, why bother? “Yes, there are plenty of ways for a band to tour that would cost a lot less money,” says Neal Carson, Dega’s catering crew chief. “DMB chooses to use us regardless of the price. They honestly care about local, organic produce. They care about the farmers. They care about the quality and they care that the people who are working for them get those same benefits too.”