The ad, created by Crispin Porter & Bogusky, shows a man locked in a motel room eating a large chicken burger. The door bursts open to reveal an angry-looking cow standing in the doorway while the voiceover says "New Tendercrisp chicken. So good you’ll cheat on beef. Only at Burger King".
In its defence, Burger King said it only used approved ingredients that would be used in-store. It appreciated all of the ingredients featured in the ad would not be visible from all sides of the burger and said it used the same building sheet Burger King staff would use in a restaurant to ensure the correct weights and ingredients were used.
Clearcast said it warned advertisers that visual representation of foodstuffs should always be in line with the standard production of the item and should not be exaggerated in any way.
It said that after receiving two samples of the Tendercrisp burger from the store it was satisfied that they were of similar size to the one in the ad.
It accepted that it was clearly established that the burger was no bigger than a large soft drink carton and only seemed bigger in the next scene because it was a "locked-in" shot.
The ASA said that because the ad showed the burger between the fingertips of one hand the combination of the images accurately represented the real size of the burger.
However the ASA upheld the complaints against the ad because the burger was shown in close-up, held by both the man's hands before a shot of it in one hand.
The ASA said: "We acknowledged the man was shown holding the burger in various other shots during the ad but noted in those shots the burger was either not fully visible or was not the focus of attention and considered that the relative size of the burger to the man's hands had not been established in these images."
The ASA purchased three Tendercrisp burgers and noted that the thickness of the burger, the quantity of additional fillings and overall weight and height of the product was considerably less than in the burger in the ad.
It said: "We concluded that the visuals in the ad were likely to mislead viewers as to the size and composition of the product."