The spring poster and press campaign showed a toy bear holding a clipboard seated next to a pack of Birds Eye Field Fresh Broccoli Florets. Text at the top of the poster stated “30% more vitamins than fresh vegetables.* I’ve just read the research.”

The Advertising Standards Authority upheld five complaints that the ad was misleading and it could not be substantiated because the research it cited, mentioned in small print on the ad, only studied vitamin C and so could not be applied to other vitamins.

The watchdog said the ad should not be run again because it broke rules about health claims and exaggeration as well as those about misleading and unsubstantiated claims.

It also said Birds Eye should not make comparative claims between frozen and fresh vegetables in future as European rules on health claims forbid products being compared to products of a different category.

Birds Eye said the ad was intended to educate consumers about the health benefits of frozen food, and directed them to further information about the study on its website.

It launched a new campaign featuring TV personality Myleene Klass last month to promote its fitness initiative ’100% active.