Some cereals marketed to children are more than 50 per cent sugar by weight, which make them a major source of empty calories, an analysis of more than one thousand cereals by the Environmental Working Group revealed.

The Environmental Working Group analyzed around 1,500 cereals, including nearly 200 cereals that are marketed to children.

The group found that cereals with cartoon characters on boxes most heavily loaded with added, unnatural sugar.

Widely popular Kellogg's Honey Smacks found to be the worst offender, with a whopping 56 per cent sugar by weight. Food Lion Sugar Frosted Wheat Puffs and Malt-O-Meal Golden Puffs were also found to be containing high amounts of added sugar.

Commenting on the findings of the study, Research Director Renee Sharp said, "That's why the federal government and food manufacturers need to hear from us. We hope the report will empower Americans to use their voices and buying dollars to demand better choices and a limit on how much sugar is added to food products that are marketed as healthy."

Nutritionist Dawn Undurraga, the co-author of the study, breakfast cereals are the single largest source of added sugar in kids' diet, after sugar-heavy foods like candy and cookies.

High amounts of added sugar in meals are responsible for increasing cases of obesity, diabetes, high blood pressure, and a number of other health problems.