As Ronald McDonald reclaims his crown as McDonald's brand ambassador, is this another indication that fictional characters are the key to success for food advertising? Although they can be corny, many fictional characters in food adverts occupy a firm position in the national consciousness.

Think Tony the Tiger, Captain Birdseye and Mr. Kipling; names that instantly conjure up affectionate feelings of nostalgia. These characters who we have known, loved (and indeed invited into our homes) through the decades, inspire loyalty and trust in consumers in a unique way. Brand values can be poured into these figures and, although they may need to adapt over the years to keep abreast of the times, their longevity proves the power they still have in today's consumer market.

However, a delicate balance must be maintained. Brands must be prepared to adapt their fictional characters to keep pace with the modern world, whilst keeping in mind that unnecessary change to a long-loved character can alienate consumers.

Change to a brand character for the sake of it can damage this relationship. It's human nature to dislike change, and our relationships with brands are similar to those with friends; we build a loyalty to certain ones and can feel betrayed if they don't act as we expect them to. In the 1990s Birdseye gave their famous Captain a face-lift, making him look younger and more rugged. This was not well received by the public who demanded the return of the fatherly old sailor and his bushy beard back on their screens, proving that the comforting familiarity of long-standing fictional characters is a remarkably powerful source of loyalty.

Although change to a fictional character can be upsetting to the die-hard fans, sometimes it needs to happen before a character becomes irrelevant to the public. For example the image of Uncle Ben was updated in 2007, when he was 'promoted' from his previous guise as a smiling rice farmer to a suited chairman of the board dispensing worldly wisdoms. Some found the change cringe-worthy in the extreme, but it was essential to move the brand away from an image that expressed an outmoded attitude towards African Americans.

The most important thing for a fictional food character to achieve is to encapsulate the values of the company or product and create a sense of emotional belonging for the customer. For me, Mr. Kipling does this perfectly. In the majority of adverts over the years, the character of Mr. Kipling has been created solely through the use of a voiceover. In this simple way, the Mr. Kipling brand attached personality to the product and linked it with messages of comfort, familiarity and reassurance, which has kept the viewer engaged. Exceedingly clever.

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