Are sugar substitutes better for you?

Are sugar substitutes better for you? (Stockbyte via Getty Images)

Define moderation? One diet soda every other day is "probably fine," said Kristin Kirkpatrick, manager of wellness nutrition services at the Cleveland Clinic's Wellness Institute in Ohio. More frequent consumption can foster a dependency for sweet flavors, she said.

Ruggiero treats herself to one diet soda a week.

"But I have a very good diet,'' she quickly adds. "It's a little treat when I want something fizzy or sweet. It's not replacing more healthy items in my diet. I eat very well, I exercise, so I keep a little stash in my fridge."

Diet soda and kids? "No artificial sweetener has any place in a child's diet, and that goes for diet soda too,'' Dudash said. Better to serve water or a nutrient-rich beverage, she added.

What is sweetening that drink? While the U.S. government recognizes a number of artificial sweeteners as safe for consumers, health organizations and advocacy groups have expressed differing views on them. They note some artificial sweeteners are still being studied, others need to be studied, and still more need to be restudied properly.

The Center for Science in the Public Interest posts a "Chemical Cuisine" page on its website ( rating the risk of various food additives, including artificial sweeteners. Sucralose is on the "safe" list. Aspartame is listed under CSPI's "caution" column. On the "avoid" list are saccharin and acesulfame-potassium, which is sometimes used with sucralose in products.

Read the labels. Jacobson said the best option is to look for a product sweetened entirely by sucralose, followed by a product using sucralose mixed with acesulfame-potassium.

Still, when it comes to diet sodas, Jacobson believes the fewer, the better.

"The best diet drink would be water or water mixed with fruit juice, seltzer or seltzer mixed with fruit juice,'' he said.