The women will replace the usual Special K slimmer models in some of the cereal brand’s communications.

One ad shows a group of women with a body mass index of between 25 to 29.9, officially classed as overweight, stepping up to a giant set of scales. Instead of their weight appearing positive messages, such as “amazing”, flash up.

The campaign will focus on encouraging women to think about some of the other positives they gain when they lose weight, rather than just focusing on what they look like or what size they are.

A Special K spokesperson says: “We want to encourage a responsible attitude when it comes to body image and to show that losing weight isn’t just about the way you look or a certain size you need to conform to, but more importantly about the way it makes you feel. The fact that we are using real women for the first time of a variety of shapes and sizes is the perfect way to encourage women to think differently about losing weight and not just focus on the numbers on the bathroom scales.”

However, the iconic Special K red swimsuit woman will appear in other advertising campaigns.

Special K’s move has echoes of Unilever brand Dove’s “Campaign for real beauty” from 2004 that featured normal-sized women.

Last year Boots trumpeted the fact its Boots’ No7 cosmetics brand carried out a “mould breaking” campaign with ads starring non-airbrushed, age-appropriate models that had not had plastic surgery.