New York - Nonfat cheese that tastes like plastic. Low-calorie soda that leaves a bitter aftertaste. Sugar-free brownies that crumble like Styrofoam.

Dieters have learned an important lesson: When you take the fat and calories out of your favorite treats, you sometimes have to say goodbye to the taste too.

But snack brands like Dreyer's/Edy's ice cream, Hershey's chocolate and Lay's potato chips are trying to solve this age-old dieter's dilemma by rolling out mid-calorie goodies that have more fat and calories than the snacks of earlier diet crazes but less than the original versions. They're following the lead of soda companies like Pepsi and Dr Pepper that introduced mid-calorie drinks last year.

It's hard to isolate sales of mid-calorie snacks since they also usually have reduced fat, or other healthy attributes like reduced sodium. But sales of all foods and drinks in which the amount of things like fat, sugar, salt, carbohydrates have been actively reduced during production have risen 16 percent to $51.72 billion since 2006, according to research firm Euromonitor International.

The mid-calorie trend is hitting at a time when companies that make sugary and salty treats are being blamed for the country's expanding waistlines. The problem is that the same things that make snacks taste good - sugar, salt, calories - also make them fattening. And many Americans don't want to sacrifice taste at snack time. Shaving a few calories enables companies to market their cakes, cookies and chips as healthier without the stigma of bad taste that goes along with some low-fat products.

It's just the kind of marketing that might attract Monica Olivas. She says she wants to lead a healthy lifestyle, including curbing her fat. But most low-fat foods just don't appeal to her.

"Sometimes companies go too far and take out all the fat - and all the flavor," says Olivas, a 29-year-old recruiter from Pico Rivera, Calif.

The mid-calorie trend is a toned-down version of the "light" craze that started in the 1990s. Back then, "low fat" or "no fat" was all the rage. But the products often fizzled.

For instance, McDonald's rolled out the McLean Deluxe, a low-fat burger, in 1991. But the burger, which was in part made with seaweed, had dismal sales. It disappeared from restaurants within five years.

Similarly, Lay's in 1998 introduced Wow fat-free potato chips that use fat substitute Olestra. But the ick factor trumped healthiness when the Food and Drug Administration said the chips had to come with a warning that Olestra may cause abdominal cramping, loose stools, and that it inhibits the absorption of some vitamins and other nutrients.

The FDA dropped the requirement for the label in 2004 after studying the matter. The chips were renamed "Light," but sales have not recovered.

"Originally, a lot of the diet stuff just wasn't good," says Richard George, chairman of the department of food marketing at Saint Joseph's University in Philadelphia. "People would say you could throw away contents and eat the box. But they've gotten better."

The new era of diet food started in the last decade. In 2007, companies began offering 100-calorie packs of popular snacks like Oreos cookies and Twinkies cakes. That's when brands started putting their focus on reducing calories - without any flavor change.

First, companies have to convince dieters that their mid-calorie snacks are not only healthy, but tasty too.

With that in mind, Hershey's in June introduced Simple Pleasures, chocolate with 30 percent less fat. A serving size of six pieces equals 180 calories and 8 grams of fat - that's 30 calories and 5 grams of fat less than the original Hershey's bar. The company is hoping that is enough to lure chocolate lovers who want to eat healthier.

Similarly, Lay's in July rolled out two new flavors of its Kettle Cooked potato chips with 40 percent less fat. The brand, which fries chips in small batches so as to use less oil than the continuous frying process for regular chips, introduced "Smokehouse BBQ" and "Cooked Sun-Dried Tomato and Parmesan."

The company says it was able to lower the calories and fat without sacrificing taste: Regular Kettle Cooked chips have 160 calories and 9 grams of fat, while the reduced-fat versions have 130 calories and 6 grams of fat.