Is Stevia a Healthy Low-Calorie Sweetener?

Q. I want to consume less aspartame, but I still want to use a low-calorie, sugar-free sweetener. What about stevia? Is it a healthy sugar substitute?

A. A 2008 survey by the International Food Information Council showed that 45 percent of U.S. consumers who are aware of low-calorie sweeteners want to use less aspartame, sucralose, and saccharin. This desire has paved the way for plant-base sweeteners such as stevia, which is extracted from leaves of the Stevia rebaudiana plant native to South America.

It takes very little stevia to equal the sweetness of sugar (stevia is 200-300 times sweeter than table sugar), so many stevia sweeteners contain erythritol, a virtually calorie-free (0.2 calories per gram) sugar alcohol that adds bulk. The extra bulk helps high-speed packagers accurately measure stevia and other low-calorie sweeteners. Erythritol is thought to be better tolerated by the digestive system than other sugar alcohols such as sorbitol. Your body absorbs very little erythritol, and studies suggest it doesn't affect blood glucose.

Manufacturers are also combining two or more sweeteners that work synergistically to pump up the flavor and cut aftertaste (and, in some cases, trim costs). "For example, if you mix sucralose with aspartame in some foods, you don't have to use nearly as much to get the same sweetness level," says Roger Clemens, Dr.P.H., spokesperson for the Institute of Food Technologists.