PHILADELPHIA -- A particular form of diet advertisement -- the "before and after" ad -- can reinforce negative feelings about the obese and perpetuate damaging stereotypes, according to a study led by a researcher at the University of Pennsylvania.  

The findings, published in the current issue of Eating and Weight Disorders, demonstrate that "before and after" ads promote an unreasonable perception of the controllability of weight, thereby reinforcing a prevailing bias toward the obese.  

"While highlighting dramatic weight loss, before and after images ignore the reality of dieting and encourage the notion that losing weight is easy," said Andrew B. Geier, lead author and a graduate student in Penn Department of Psychology.  "When someone believes that weight is easily controlled, it reinforces the negative stereotypes that obese people are inherently lazy or lack discipline."

In the study, 59 people were either exposed to a "before and after" diet ad of an obese woman who lost weight or exposed only to the "before" or "after" picture embedded in a different ad.  The subjects' attitudes about overweight people were then assessed.  Across all subjects, a strong anti-fat bias was present.  Subjects viewing "before and after" ads indicated that weight is more easily controllable than did subjects who viewed only the "before" or the "after" pictures.  

The study also asked participants to rate pictures of the attractiveness of the "before and after" model.  The researchers found that viewers rated pictures of obese individuals (the "before" picture) as more attractive when accompanied by a picture of that same individual when thin (the "after" picture).  

"Viewers typically see positive change as a good thing.   When people notice a frog become a prince, they tend to think more highly of the frog in retrospect," Geier said. "However, subjects rated thin women as less attractive when they were allowed to view the 'before' pictures.  Seeing that a thin woman was once obese apparently detracts from her present appearance."

The overall impact of stigmas toward the obese is unknown, but the researchers believe that they may influence further weight and eating disorder psychopathology.

"We study stigmas to understand their origins in the hopes of eradicating them," Geier said.  "While obesity is a serious health problem and most people agree that stigma is wrong, few appreciate the damage that these biases can cause.  One thing that should be obvious is that shaming someone is not the same as helping them."

Kelly D. Brownell and Marlene B. Schwartz of Yale University Department of Psychology co-authored the article.