The allergies of the few are affecting the diets of the many

I'M standing in a space the width of an airplane aisle, staring at frying oils. It's the kitchen of the Stapleton, Colorado, location of Next Door, one of the country's most-high-profile casual restaurant companies.Here, eating restrictions don't just pepper the menu, signalled through such acronyms as "GF" (gluten-friendly), "DF" (dairy-free), "V+" (vegan) and "GFO (gluten-friendly optional). They define it.

Instead of topping a salad with nuts, Next Door chefs sprinkle on sunflower seeds. Before frying calamari or pickles and pepperoncini, they dredge them in cornstarch or polenta, respectively, instead of the traditional wheat flour. For their veggie bowl, they use quinoa, because it's a whole grain that doesn't have gluten.

The chefs also use three separate fryers for dishes that are vegan, vegetarian or that contain gluten and/or seafood (for their twice-weekly beer-battered fish tacos). Nothing gets cooked in the wrong oil.