A campaign for the drink Lucozade Sport has been banned following complaints about its central claim that the product "hydrates and fuels you better than water".
The television advertisement and a poster drew 63 complaints, including one from the National Hydration Council, challenging whether the claim by GlaxoSmithKline (GSK) broke advertising rules.
The TV ad showed two groups of men, one drinking water and the other Lucozade Sport, running on treadmills while being monitored by technicians before a voiceover said: "At the limits of your ability, you need to replace the electrolytes you lose in sweat, keep your body hydrated, give your body fuel."
It continued: "Lucozade Sport gives you the electrolytes and carbohydrates you need, hydrating you, fuelling you better than water."
The poster featured an image of a professional rugby player and stated: "Hydrates and fuels you better than water."
GSK said Lucozade Sport was a carbohydrate-electrolyte solution, and that two health claims for such solutions had been authorised by the European Union under Regulation 432/2012, after a scientific assessment undertaken by the European Food Safety Authority (EFSA).
The company said the claim that Lucozade Sport "hydrates you better than water" was fully consistent with the authorised claim "carbohydrate-electrolyte solutions enhance the absorption of water during physical exercise".
Regarding the "fuels you better than water" element of the claim, GSK said it "strongly believed" that consumers would recognise that Lucozade Sport provided calorific energy, derived predominantly from carbohydrate, whereas water was calorie-free and could not therefore be said to provide "fuel" at all.
GSK said it "therefore felt that common sense dictated that the claim should be acceptable, because consumers were unlikely to misunderstand it".
The Advertising Standards Authority (ASA) noted that the claim "hydrates and fuels you better than water" did not appear on the list of authorised health claims in respect of carbohydrate-electrolyte drinks, but understood that the regulations allowed for a "degree of flexibility" to aid consumer understanding.
But it ruled that GSK did not accurately reflect the authorised claim in its rewording of it for the campaign, specifically by failing to make it clear that the benefits of the drink would only be achieved during prolonged endurance exercise.
The ASA added: "Even if we had accepted that 'fuels' was an acceptable rewording of the authorised claim 'contributes to the maintenance of endurance performance during prolonged endurance exercise', we noted that that claim did not make any comparison with water, and we therefore considered that it would not have been acceptable for GSK to state that the product 'fuels ... better than water'."
The ASA said: "The ads must not appear again in their current form. We told GSK to ensure that they retained the meaning of any authorised health claims if they reworded them to aid consumer understanding, and to avoid substituting product names for the nutrient, substance, food, or food category, for which a claim had been authorised."
National Hydration Council general manager Kinvara Carey said: "We are pleased with the decision by the ASA to uphold our complaint regarding the high-profile Lucozade Sport advertising campaign.
"There is already much confusion over the role of sports drinks and for the majority of people participating in exercise and sporting activities, water is all that is needed for effective hydration.
"The majority of sports drinks contain calories and may only have a positive contribution to make to professional athletes and those participating in high intensity, endurance activity".