Publicity for vitamin-enriched water made by Coca-Cola fell flat with the advertising watchdog for "misleading" claims about its nutritional benefits.

Posters and a leaflet for Vitaminwater featured slogans such as "more muscles than brussels" and "keep perky when you're feeling murky".

An advert for the "power-c" drink said: "Popeye had it easy. A can of spinach and he bulked up ... the nutrients in this bottle won't enable you to walk on mud, or become a strapping sailor man, but they will help you beat your granny in an arm wrestle."

Another read: "If you've had to use sick days because you've actually been sick, then you're seriously missing out my friend. The trick is to stay perky and use sick days to just, erm, not go in."

Complaints were made about the implications that the drinks were equivalent to vegetables and had health benefits such as raised energy levels and resistance to illness.

Two people also said that the adverts implied that the drinks were "healthy", even though they contained 4.6g of sugar per 100ml.

Coca-Cola insisted the advertising was "humorous and irreverent" and the reference to "brussels" referred to the nickname for action film star Jean Claude Van Damme aka "the Muscles from Brussels", not sprouts.

The reference to staying "perky" meant mood rather than fighting illness, and consumers would not think that arm-wrestling their granny would need more energy.

But the Advertising Standards Authority upheld the objections.

It said of the power-c advert: "We noted that the word "brussels" was not capitalised and considered it was not clear from the ad, or its context, that the claim intended to refer to a well known actor. We considered that the claim was therefore ambiguous and likely to be interpreted by consumers, in conjunction with claims such as "Popeye had it easy", as a comparison between the nutritional benefit of the 'power-c' drink and the vegetable Brussels sprout."

Another ad made a direct link between avoiding illness and the drink, but there was no evidence that the product would boost the immune system, strength or mood.

The ASA also found that the drinks contained nearly a quarter of the recommended daily amount of sugar in 500ml but the publicity made it likely that consumers would think the products were "healthy".

The adverts must not be used again.