From sodas to gelatin, stores are full of sugar-free choices. But something else is making those foods sweet – and those ingredients are not always healthier.

“I don't recommend sugar substitutes or artificial sweeteners myself,” registered dietitian Cynthia Sass said.

Some dietitians worry that sugar substitutes, like Splenda and Equal, can trigger bad habits.

“There's some indication they may stoke a sweet tooth so you'll be looking for sweets elsewhere or you're just obsessively thinking about sweets all the time,” Sass said.

Even though the government has tested and approved the sweeteners, shoppers like Christine Walsdorf have their doubts.

“I think there's questionable data about it so if I can avoid it I avoid it,” Walsdorf said.

Suspicion about artificial sweeteners dates back to the 1970s when saccharine carried a warning label.

The cancer warning came off more than 10 years ago, but nutritionists are still wary. They worry that dieters assume sugar-free means it will help you lose weight.

That's not always true since the products often contain fats and carbohydrates.

When comparing Oreos and sugar-free Oreos, there is only a 5 calorie difference per cookie.

The sugar-free version, which uses an artificial sweetener, is also smaller, possibly encouraging people to eat more.

Also, the ingredient list is longer on the sugar-free cookie, which leads experts to say that if it reads like a science experiment look for a healthier option.

Artificial sweeteners might be a good alternative to sugar if you have diabetes.

However, there are concerns about how sugar substitutes are labeled, and diabetics should always check with their doctor or dietitian about whether any of those products may affect their blood sugar.