Breakfast cereals still contain “shocking levels” of sugar despite calls for manufacturers to take action, a new report has warned.

The sugar content of breakfast cereals - reaching 35% in some cases - was of “major concern”, claimed the study published today by Action on Sugar and Consensus Action on Salt and Health (CASH) at Queen Mary University of London.

Children’s breakfast cereals were particularly worrying, it added, with a typical 30g serving containing a third of a four to six-year-old’s maximum daily recommendation (19g per day or five teaspoons of sugar) for sugar intake in the UK.

Crunchy nut-style cereals were found to contain the highest levels of sugar and Kellogg’s Crunchy Nut was named as one of the worst offenders, with 11g of sugar per 30g serving.

“Our study shows that the sugars content in breakfast cereals has been steadily high since 1992, despite the ever-increasing evidence linking sugars with dental caries, obesity and Type 2 diabetes,” said joint first author Kawther Hashem, a registered nutritionist, for Action on Sugar at Queen Mary University of London.

“The variation in sugar content between similar products clearly demonstrates there is no technical reason whatsoever why cereals contain such high levels of sugar.”

In contrast, the salt content of popular breakfast cereals has fallen by approximately 50% over the past decade as a result of the industry’s salt reduction programme, the study said, though it warned some cereals still contained too much.

Kellogg’s was again named as one of the worst performers, with two Kellogg’s Special K variants failing to meet the 2017 salt target, it claimed.

However, Kellogg’s insisted it was “committed” to reducing salt and sugar content in its cereals.

“We have tackled salt, reducing it in our cereals by 57% over the last two decades. Thanks to our ongoing sugar reduction work, by the end of 2017 we will have removed 2,000 tonnes of sugar from the nation’s diet too,” said a spokeswoman.

“Our long-term sugar reduction efforts have already seen sugar come down in some of our biggest brands like Special K and Bran Flakes, and more recently we have reduced sugar in our biggest-selling children’s cereal Coco Pops by 14%.”