A report from the BBB shows food makers have also been lowering the sodium and calorie count and boosting the fiber in their most popular kid's cereals.
Here are the numbers.
More than 70 percent of the cereals advertised to children have no more than 10 grams of sugar.
A third have 9 grams of sugar or less.
Before this voluntary program started in 2006, some of the cereals advertised to kids had 15 or 16 grams of sugar per serving.
The majority of cereals advertised to children -- 71 percent -- have at least eight grams of whole grains. That's a half serving.
A third contain at least 12 grams.
And more than a third have more whole grains than any other ingredient.
The BBB calls these changes "a significant improvement." And there's no question about that, but there's still a lot more to do.
Nutrition experts at the center for science in the public interest say kids cereals still have too much sugar.
They point out that a cereal with 9 or 10 grams of sugar per serving is still about one-third sugar.
Cereals Advertised to Children Are Less Sugary