Chef Chris Cryderman, a 40-year veteran of upscale restaurants in his native Detroit and in Colorado, said diners have become more attuned to food allergies and issues in the past decade.

And they are quickly and consciously drawing correlations between how they feel and the food they eat.

"I just really think it's kind of a combination of us feeling that something's wrong and then finding out why," said Cryderman, who ran a health-food restaurant in the 1980s and has spent his career accommodating diners' dietary requests.

"We have some regular clients that come up to our truck and tell us 'We can't have this,' 'We can't have that,' and I've never had a problem accommodating any of them."

Cryderman and his son rolled out their Chef's Kitchen and Catering truck in November and quickly built a reputation in Tucson's food-truck scene for accommodating special needs.

"They have a separate cook (surface) and utensils for vegans," said Travis Miller, who owns the nearly year-old Serial Grillers. "We offer vegetarian on our truck, but it's not vegan," he said. "They have a separate grill and everything."

Cryderman said the issue of food allergies heightened in the last decade because so many people are aware of problems from eating processed food.

"We have a couple of items that are gluten-free on the menu. I also tell them the things that we can adapt to fit their dietary needs," he explained. "For example, our falafel is gluten-free unless you put it in a pita. We tell them you can have it as a lettuce wrap or put it on the side. The lettuce wrap is the most popular because they can wrap it and still eat it like a sandwich."

Mukhi Singh follows Cryderman's lead when it comes to separating vegan and non-vegan dishes.

"We make an honest effort to have a few vegan dishes - definitely some vegetarian dishes," he said. "That's a large part of our business."

Singh rolled out The Twisted Tandoor food truck on Dec. 26, serving up authentic north Indian cuisine that he and his wife, Roop, were raised on in New Delhi.

"Most (Americanized) Indian food is a little blander than what we do. People love the full-blown flavors that we are serving," he said. "What you get from us is what we will serve in our homes, what we grew up eating. There's no Americanization, and I can promise you there's no bastardization of what we do."

Because of that, Singh takes care to explain the nuances of his Indian cuisine, including discussing the ingredients with people concerned about food allergies and issues.

"We are trying to make sure that they know what is in it to the best of our ability," said Singh, who has spent most of his 13 years in Tucson importing and selling furniture from India.

"We really would love to look into local organic products. The only problem is the dependability and the availability on a constant basis," he said.

"One of the things we do is goat meat. Willcox has some, but they are very undependable when it comes to their supply."