Once upon a time, the lowly fried pork rind might have found its fans in places like stock-car tracks, tobacco fields, steel mills, 7-Elevens and fish-bait shops.

It was the perfect salty snack for a blue-collar binge. Great with a cola. Superb with Saturday afternoon football.

But the crunchy treat rarely rose above its station. It had become as much a symbol of its class as mullets, tube tops and Dixie flags. After all, along with Chippos, Krusty Burgers, doughnuts and honey-roasted peanuts, pork rinds are one of Homer Simpson's favorite foods.

Out in Lima, Ohio, Rich Rudolph didn't have a problem with that. As president of Rudolph Foods, the world's largest producer of pork rinds, he had seen a respectable family business with a dedicated consumer base rising out of those demographics.

Of course his father, who started the business more than 50 years ago in Chicago, and his mother, a home-economics teacher who created the recipe for deep-fried pig skin, might have liked to have seen a more expansive market. After all, Rudolph's dad always imagined something more for the often ballyhooed pig part.

Then a strange thing happen. A year or so ago, a New York television producer phoned and said he had heard that super models were eating pork rinds. Rudolph, who had rarely done much advertising, could not believe it. He suddenly found himself on network television responding to queries about the latest fad in low-carb dieting.

Yep, pork rinds.

Last year, Rudolph's company grew 22 percent. This year, with 35 percent growth, the company is in the midst of a major expansion.

"We always knew the product was better for you than the general perception," Rudolph said. "But we were never thought of as a diet food before. We never imagined getting into the 'Better for You' section of supermarkets."

What's "better" about pork rinds depends on the diet. And among the legions of low-carb dieters - followers of Atkins, South Beach and similar regimens - the high-protein, low- (or no-) carbohydrate traits that are natural to fried pig flesh make pork rinds a great substitute for pretzels, popcorn and potato chips.

"It's still junk food," said Leslie F. Miller, owner of La Vida Lo-Carb store on York Road. But if you're avoiding chips, crackers and traditional sweets, and still want to enjoy a very crunchy, protein-rich snack, Miller vouches for low-guilt bags of pork rinds of the most untraditional kind: Gram's Gourmet Crunchies - crispy pork rinds lightly flavored, including a cinnamon brand and a dry cheddar cheese.

For those unaccustomed to such delicacies, and for those who know only the slightly greasy mouth feel of the old-fashioned rind, the fancier brands, with their whey powder, Splenda and off-center tastes, can be a fine substitute. "I've been open for four months," said Miller, "and we have sold 30 cases of pork rinds. The cinnamon doesn't even taste like pork rinds. They taste exactly like cinnamon toast."

Julee Dennis, a 46-year-old low-carb entrepreneur and former rock 'n' roll singer from Pflugerville, Texas, started Gram's Gourmet after dumping 114 pounds on the Atkins diet in 1998. She admits it seemed like a crazy thing to do. But in the Internet chat rooms where she would talk to fellow low-carb dieters about their wish lists for foods, the notion of a new niche for the pig part actually made some sense.

"I've done a lot of things that most people would think are crazy or risky," said Dennis. "But I just had an intuitive feeling about this one. Most [snack-food] manufacturers didn't know what people were talking about on the ground level, so for me it was just a matter of knowing what people wanted and then finding a way to give it to them."

Dennis, who - along with her three grandchildren - is among the company's taste testers, says her rinds appeal to a higher-end clientele willing to spend $3.49 for a 4-ounce bag of rinds - about a $1 more than competing brands.

Last year, in her first full year of business, the company sold more than $1 million in pork rinds. This year, she expects to triple that. With deals now under way with mainstream grocery stores and nine more flavors, including chipotle lime, in the works, Dennis believes pork rinds have found a future in a more upscale marketplace.

At Utz Quality Foods Inc. in Hanover, Pa., the sales of pork rinds are also on the rise, and managers of the snack-food company attribute it to low-carb dieters. "We've handled pork rinds for a quite a while," said company vice president Gary Labs, "but with the low-carb emphasis, it's really taken off. We added some new flavors and we've started packaging them in these big plastic overgrown fishbowl containers, and they're selling really well."

In a business where blue-collar tastes once predominated, the sudden change is still hard to believe for a guy like Rudolph.

"There's a lot of polarity in the market now," Rudolph said. "Our long-term customers are glad to know that they've been eating something that's not nearly as bad as the perception was. On the other hand, there is a new group of consumers who are a younger, female population trying it because it's zero carbs and has that nice light bacon taste."

Still, he's not yet sure if his fans include the New York super models, as he once heard.

"That's something we still haven't sorted out," he said. "If we could just track one down, we'd try to get an endorsement."

How snacks stack up

Utz Regular Potato Chips

Per serving (1-ounce): 150 calories; 9 grams fat; 2 grams saturated fat; 0 milligrams cholesterol; 95 milligrams sodium; 14 grams carbohydrate; 1 gram fiber

Utz Regular Pork Rinds

Per serving ( 1/2 -ounce): 80 calories; 5 grams fat; 2 grams saturated fat; 15 milligrams cholesterol; 230 milligrams sodium; 0 grams carbohydrate; 0 grams fiber