Not long ago, high-protein bars were the space food of choice for dieters who wanted their sweet fixes in alternative form. But with diets such as Atkins and the Zone reinforcing the idea that carbohydrates are the main stumbling block to weight management, low-carb bars are crowding the racks near the registers at supermarkets, pharmacies and health-food stores. "They're so popular because people think, I'll have this instead of a candy bar," says Sharron Dalton, professor of nutrition at New York University. But experts warn that just because these bars are low in "net carbs"--the kind that affect blood sugar and can contribute to weight gain they won't necessarily cause the pounds to melt away. Factors such as calories, fat and fiber and whether the bars are used as a snack or a meal replacement also weigh in. "You'll gain weight on anything that's an energy source if you intake more energy than you use," says Dalton. Bars that are lower in calories and higher in fiber are best. TIME tasted five popular low-carb bars, and here's how they stacked up:
--NITRO-TECH PEANUT BUTTER CHOCOLATE CHIP Our favorite in taste and consistency. But it has the most calories (300) and 5 g of saturated fat.
--THINK THIN CHOCOLATE FUDGE LITE Flavorful, with a smooth, soft texture and the least chemical taste. Its 240 calories aren't excessive, but it has just 1 g of fiber.
--KETO BAR CARAMEL NUT CRUNCH Appealing, crunchy texture, a nutty taste and no oily residue but only 2 g of fiber.
--DOCTOR'S CARBRITE DIET CHOCOLATE COVERED BANANA NUT Package says, "Rated #1 in Taste!" But it rated lowest for us. Only 195 calories, but 0 fiber.
--MYOPLEX CARB SENSE BLUEBERRY Pleasant scent, but the taste didn't measure up. Contains 4 g of fiber and 3 g of sugar.