Sugar alcohols (sorbitol, lactitol, mannitol, maltitol, xylitol)

Found in sugar-free candy and low-fat products, including diet bars.

What is it?
Regular sugar manufactured with hydrogen molecules.

How safe is it?
Safe, with side effects. For some, taking as little as one gram of sugar alcohol (half a stick of Extra gum) can cause diarrhea, cramps, gas and bloating. “They are safe,” says Kroger. But it all depends on the dose. The more you eat, the more likely you are to see symptoms. “You have to learn how much you can tolerate,” he says.

Neotame

Found in baked goods, gum, frozen desserts, jelly, gelatin, soft drinks, pudding, processed fruit and fruit juices.

What is it?
A heat stable, water soluble white crystalline powder.

How safe is it?
Safe. Approved for use as a general sweetener by the FDA in 2002, Neotame has been deemed safe for human consumption. The FDA examined over 110 studies to ensure that the sweetener does not have harmful effects.

Acesulfame K

Found in diet soft drinks, low-cal frozen desserts and cookies, and sugar-free candy and gum.

What is it?
Synthetic chemicals that are bonded to potassium.
How safe is it?

Long-term effects unknown. More than 90 studies have verified its short-term safety; however, acesulfame hasn't been around long enough to determine whether long-term use may cause cancer, according to a review published in the Annals of Oncology. Kroger isn't worried about long-term effects, though. “Acesulfame K is safe,” he maintains. “It is approved (by the FDA). This is where I put my faith…they have a very elaborate process of approving something.”

Saccharin (Sweet'N Low)

Used as a direct sugar substitute.

What is it?
A synthetic chemical that starts with toluene.

How safe is it?
Use with caution. One major U.S. study found a link between heavy consumption (six or more packets a day) and a slightly increased risk of bladder cancer. And according to Andrew Laumbach, a consumer safety officer in the FDA's Office of Premarket Approval, it's been proven to cause cancer in animals. The good news: animal studies do not necessarily mean that this substance will have the same effect on humans. “Saccharin does no harm,” Kroger says. “A rat is not a person. A man is not a mouse. [Saccharin] may be a rodent carcinogen…but it may not be a human carcinogen.” Plus, he explains, the studies that found a link between saccharin use and cancer in rodents tested massive and unrealistic amounts of the sweetener. The mice were fed the equivalent of over 800 cans of soda every day, way more than any human would ever ingest in that period.