The first ad appeared in the Atlanta edition of USA Today, ABC News reported. It will run Thursday in the Atlanta Journal-Constitution, and the Atlanta-based company plans a national campaign.
The ad defends low-calorie sugar substitutes in general and the sweetener aspartame in particular. It is titled "Quality Products You Can Always Feel Good About."
"Time and again, these low- and no-calorie sweeteners have shown to be safe, high-quality alternatives to sugar," the copy says. "In fact, the safety of aspartame is supported by more than 200 studies over the last 40 years."
The company has seen recent drops in sales of Coca-Cola with regular coke falling 1 percent and the diet option 3 percent.
While most studies have found no link between aspartame and disease, one study found people who consume diet soft drinks are more likely to be obese and to suffer from diabetes and other diseases than those who do not.