"Train hard, eat right and earn your stripes," was the Kellogg slogan that accompanied two boys dribbling a football through the streets of Rio whilst being coached by brand mascot Tony the Tiger, shown in cinemas across the UK.
But Tony's football coaching career was put into early doubt as an anonymous complaint to the Advertising Standards Authority (ASA) objected to the "eat right" part of the advert slogan, because it falsely implied that Frosties were healthy when in fact they were laced with sugar.
And, after considering arguments from both sides, the ASA has now upheld the complaint, warning Kellogg not to repeat the "eat right" claim in future adverts.
An ASA statement said: "Because it considered that Frosties had a high sugar content, the Authority concluded that the implication [in the advert] was misleading." Justifying its decision, the ASA said that whilst Frosties contained 12 grams of sugar per 30 gram serving, Weetabix and Bran Flakes contained 11 grams and five grams less sugar respectively for a similar serving.
The authority added that a bowl of Frosties with milk contained more sugar than an apple, fruit juice or plain yoghurt. The ruling is embarrassing for Kellogg which only a few weeks ago ran a promotional National Breakfast Week in the UK, advertising the health benefits of "the most important meal of the day".
But Kellogg has railed against the ASA decision, asserting that sports nutritionists agreed that cereals like Frosties, which were low in fat and high in simple carbohydrates like glucose, were a good energy source for people playing sport.
The company also said that a 30 gram serving of Frosties provided 25 per cent of the recommended daily intake of six B-group vitamins and 17 per cent of the recommended daily calcium and iron intake.
Chris Wermann, European director of corporate affairs for Kellogg, told BakeryAndSnacks.com of his surprise that "one letter to the ASA can cause a ban on something clearly being done with all the right intentions".
"We have specifically used advertising air time to engage kids to eat more sensibly and be more active. We are doing things for all the right reasons. There is no excess sugar in Frosties and sugar levels are well below the daily recommended allowance for kids," said Wermann.
Wermann nevertheless admitted that Kellogg would now have to re-think its advertising strategy, and the ASA ruling has highlighted the issue of tighter controls on companies advertising their products to children.
Sue Davis, principal policy advisor for consumer campaigning group Which?, welcomed the ASA decision: "It seems as if the ASA is finally responding to the mounting evidence showing that advertising influences the foods that children choose to eat.
"If the government is serious about curbing the obesity epidemic it has to lose the couch potato approach towards companies misleading parents who are trying to encourage their children to eat more healthily," she said.
Which? wants the government to use its forthcoming Public Health White Paper, out later this month, to restrict advertising of foods high in fat, sugar and salt during children's viewing times. The paper is already likely to include provision for healthier school meals.
The ASA decision on Kellogg also adds to the growing tension between the UK government and food industry over the amount of salt, sugar and fat going into products.
The last month alone has seen the launch of a campaign by the Food Standards Agency to reduce salt levels in products and consumer diets and also rumours of a future government campaign, aimed at cutting sugar in a range of products from baked goods to ready meals.