Stevia is perhaps unique among food ingredients because it’s most valued for what it doesn’t do. It doesn’t add calories. Unlike other sugar substitutes, stevia is derived from a plant.

The stevia plant is part of the Asteraceae family, related to the daisy and ragweed. Several stevia species called “candyleaf” are native to New Mexico, Arizona and Texas.

But the prized species, Stevia rebaudiana (Bertoni), grows in Paraguay and Brazil, where people have used leaves from the stevia bush to sweeten food for hundreds of years. In traditional medicine in these regions, stevia also served as a treatment for burns, colic, stomach problems and sometimes as a contraceptive.

Today, stevia is part of the sugar substitute market.

The U.S. Department of Agriculture estimates Americans  added more sugar  to their diet every year since the 1970s until 2000. When Americans dropped the added sugar, they turned to sugarlike extracts. The sugar substitute market was estimated to be worth $10.5 billion in 2012. And the market may be growing. Just 18 percent of U.S. adults used low- or no-calorie sweeteners in 2000. Now, 24 percent of adults and 12 percent of children use the sugar substitutes, according to a 2012 review in the American Journal of Clinical Nutrition.