Breakfast cereals in South Africa, particularly those targeting children, have for some time made some reasonably bold health claims. This is despite most containing large amounts of sugar - sometimes in higher quantities than the vitamins and minerals they advertise.

Andrew Thompson | Business Insider SA

Most leading cereal brands for sale in this country continue to advertise the inclusion of vitamins, minerals, iron, multigrain, fibre, or even probiotics. Some leave the interpretation of common phrases like "high in", "source of", and simply "with" up to the consumer. Others, like several Kellogg's cereals, make a direct claim that some of their breakfast cereals may aid with "growth" and "development". 

Although most breakfast cereals on supermarket shelves do contain some vitamins, minerals, healthy grains, or fibre, most also have high amounts of sugar. 

But according to experts, eating too much sugar can harm health - and cutting back on some sugars could make it easier to concentrate and stay alert. In particular, experts warn against overeating processed and refined sugar - common in items like breakfast cereal.

At least five breakfast cereals directly targeting children with colourful boxes and adults with health claims have more than 30 grams of sugar for every 100 grams of cereal eaten. 

The top ten sugar-filled cereal types have more than 25 grams of sugar per 100 grams, which equals more than a quarter of sugar for every serving. 

And some brands that tacitly purport to be healthy, or contain labels such as "light", or for toddlers, also have surprisingly high sugar contents. Of the products checked by Business Insider South Africa, a "light" ProNutro had 25.8 grams of sugar per 100 gram, and a chocolate flavoured version of the same product targeting parents with toddlers had 23.4 grams.

This sugar content per 100 grams in as many as 40 different breakfast cereals is higher than items that may be considered unhealthy or desert foods - like some vanilla ice cream and even a typical Coke can.

Some local iterations of global cereal brands also have higher sugar levels than those available in foreign markets.

For example, local Kellogg's Rice Krispies Vanilla has a sugar content of 21.7 grams per 100 grams. The original brand in the United Kingdom, stocked on South African shelves after a revolt, has just 7.9 grams. And in the United States, it has 10 grams of sugar per 100 grams.

The same is true for Coco Pops in the United Kingdom - the UK version has nearly half the amount of sugar per 100 grams as the version available in South Africa.

Here's how much sugar is in some of South Africa's biggest cereal brands.