Weetabix bosses have been told to pull a phone app that branded children "a failure" unless they ate the cereal every day.
The Advertising Standards Authority ordered the "Weetakid" app be pulled after evidence showed that it made children feel inferior.
Messages included: "What?! No Weetabix?! Why make things harder for yourself?," "A failure to prepare is preparation for failure!" and "No Weetabix? Disaster!"
Weetabix's lawyers argued that children would only interpret the messages in the context of the game world.
But researcher Agnes Nairn and the Family and Parenting Institute said the game exploited children's naivety and manipulated their self-esteem with direct pushes to buy Weetabix's products.
A government guided by common sense would respond to news that publicly owned Royal Mail has increased profits to £403 million by scrapping plans to flog off the service.