Increasingly common ads and catalogues featuring plus-size models are unlikely to work on their intended customers. That’s according to a new study by researchers at ASU, the University of Cologne in Germany and Erasmus University in the Netherlands, which demonstrates a link between model sizes in advertisements and the self-esteem of consumers looking at the ads.

“We believe it is unlikely that many brands will gain market share by using heavy models in their ads,” said Naomi Mandel, marketing associate professor in the W. P. Carey School of Business at ASU. “We found that overweight consumers demonstrated lower self-esteem – and therefore probably less enthusiasm about buying products – after exposure to any size models in ads (versus ads with no models). Also, normal-weight consumers experienced lower self-esteem after exposure to moderately heavy models, such as those in Dove soap’s ‘Real Women’ campaign, than after exposure to moderately thin models.” Download Full Image

Mandel and her colleagues performed a series of experiments based on the popular idea that looking at extremely thin models can negatively affect consumers’ self-esteem and possibly even lead to eating disorders in young girls. That belief is why fashion show organizers in Milan, Italy and Madrid, Spain, recently banned super waif models from their catwalks.

In the new study, researchers took the link between model size and self-esteem even further by factoring in the consumers’ own body size and self-esteem before looking at the ads. Although they did confirm that exposure to extremely thin models can be damaging to most women’s self-esteem, they also found some surprising effects.

“We show it is not just the size of the models in the ads, but also the relative distance between the consumer’s size and the model’s size that affects self-esteem,” Mandel said.

In the experiments, hundreds of female students were categorized as having low, normal or high body mass index (BMI) based on their heights and weights. They were then invited to a lab, but were not told the true nature of the study. They were shown a variety of ads and told to answer several questions, only some of which were truly related to the study. The questionnaires showed the participants’ self-esteem shifted based on the model sizes they saw in the ads and whether they considered themselves to be similar to or different from those sizes.

Low-BMI, thinner women tended to experience a boost in self-esteem when they viewed all models because they identified positively with the thinner models and saw themselves as different from the heavier models. Higher-BMI, heavier women dropped in self-esteem when looking at all models because they saw themselves as different from the thinner, idealized ones and similar to the overweight models.

Normal-BMI women had the most shifts in self-esteem, depending on what types of images they saw and could therefore be the most influenced by pictures in ads. For example, if they viewed a moderately thin model, they felt similar and good; if they saw a moderately heavy model, they worried they were similar and overweight.

These findings could be used to prompt changes in behavior. For example, if a normal-size woman sees moderately heavy images in ads for weight-loss products, she might feel overweight and be more inclined to buy a diet plan or gym membership. The same premise could apply to using heavy images in public service announcements aimed at fighting the obesity epidemic.

Dirk Smeesters, marketing associate professor of Erasmus University, and Thomas Mussweiler, social psychology professor of the University of Cologne, worked with Mandel on the study, which will be published in April’s Journal of Consumer Research.