The Advertising Standards Authority (ASA) acted on a complaint that the claim " ... eat right ...", in a Frosties commercial that depicted children playing football, misleadingly implied the product was healthy.
They upheld the complaint, because despite evidence supplied by Kellogg's, 'the ASA considered that Frosties had a high sugar content.'
Consumer groups welcomed the adjudication that 'finally responded to mounting evidence showing that advertising influences the foods that children choose to eat,' said Sue Davies, principal policy adviser for the Consumers Association magazine Which?
The UK magazine, that since 1957 has been fighting for consumer rights, added it wants to see the government using the opportunity presented by the forthcoming Public Health White Paper to include advertising restrictions on foods high in fat, sugar and salt during children's' viewing times.
Consumer groups have come down heavily on the food industry, accusing it of playing a key role in today's obesity epidemic. About 300 million people worldwide are obese and 750 million overweight.
Davis added: "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."
Sales of breakfast cereals in Europe have been enjoying strong growth on the back of the healthy eating message with recent research on the French market alone showing that healthy cereals registered a 20.4 per cent value increase in the year to March 2004.
But the figures, from French market analysts Xerfi, show that the far less healthy chocolate cereals targeted at children showed the most spectacular growth - 35.7 per cent on the previous year, according to the report.
Despite repeated pledges to tackle the problem, many of the big brand breakfast cereals on supermarket shelves in the UK still contain excessive levels of sugar, salt and fat, claims recent research from Which?
Earlier this year the group investigated 100 cereal brands produced by the five biggest cereal manufacturers (Quaker, Weetabix, Nestle, Kellogg's, Jordans) to see whether their healthy image was really justified.
They found that 85 per cent of them contained 'a lot of sugar' (10g or more per 100g), 9 per cent contained 'a lot' of saturated fat (20g/100g) and 40 per cent contained 'a lot' of salt (0.5g of sodium/100g).
Of most concern, according to Which?, were the cereals marketed to children. Out of the 28 cereals investigated by the Consumers' Association, some 32 per cent contained 40 per cent of sugar or more and 64 per cent contained 'a lot' of salt.
Martin Paterson, deputy director general of the Food and Drink Federation in the UK, defended the cereal manufacturers against the Which? claims.
"Breakfast makes a major contribution to a well-balanced diet. In May 2003, the Food and Drink Federation announced an industry wide programme to reduce salt - or more precisely sodium - for breakfast cereals. The programme showed a 16 per cent reduction in sodium achieved since 1998 in the sector, and an expectation that new products coming to market will continue the trend for products with lower sodium levels."