Can media images of obese people undermine health messages? An experimental study of visual representation and risk perception.

BACKGROUND: Images depicting morbidly obese models [i.e. body mass index (BMI) >40] often accompany media articles about the health risks of being overweight (i.e. BMI 25-30). Little is known about the effect of this mismatch on people's understanding of risk, and perceptions of message relevance. METHODS: In total, 563 participants (291 overweight/obese and 272 healthy weight) were randomly allocated to read a health message about the risk of heart disease posed by being overweight, presented alongside (i) a photo of an overweight model, (ii) a morbidly obese model or (iii) no photo. Between-group differences in the primary outcomes of message relevance, and the body size perceived to be 'at risk', were assessed, and the potential moderating effects of motivation, weight concern and existing risk knowledge explored. RESULTS: Overweight and obese participants in the exaggerated (morbidly obese) image condition interpreted health risks to relate to a larger body size than those who saw no image (F(2, 290) = 4.06, P = 0.02). There was no experimental effect on perceived personal relevance (F(2, 290) = 0.25, P = 0.38). No significant moderation effects were detected, and there was no effect of study condition in healthy weight participants for either outcome. CONCLUSION: The findings suggest that the use of morbidly obese models in messages regarding the health risks of being overweight may undermine the impact of these messages among those who they most aim to reach; the reader may perceive a reduced risk of being 'only' overweight, and that a higher weight is needed for the negative effects of excess weight to occur.