Endorsements play an important role in marketing communications. For international marketing communications, marketers must be cognizant of how the portrayal of body ideals and cultural background of endorsers can affect marketing communications. Two experimental studies showed that body image comparisons and the effectiveness of endorsers varies according to the type of body shapes portrayed and the body mass index (BMI) of the respondents. In the first experiment, the success or failure of endorsements was found to be influenced by their body shape and to some extent the cultural background with respect to the type of product or service promoted. In a second experiment where more realistic or medium-thin and medium-fat body shapes were used, source attractiveness was not influenced by body shape, while interest in the advertised brand increased for a thinner model. This may have occurred because body image comparisons were more obtainable for those in the second study, where more realistic body shapes were viewed in advertisements. Body mass index (BMI) was also found to influence the results, particularly if a poor body shape comparison triggers a poor body image. Counterfactually, this seems to occur with women with lower BMIs who view advertisements for fatter women. It appears that the use of body image and ethnic type of models should be carefully considered by marketers so that they are relevant for their target audience. The use of more obtainable and ethnically relevant models may provide more effective advertising copy and be more socially responsible. In order to create interest in advertised brands, marketers may not need to use ultra-thin models. Marketers must also balance the promotional effectiveness of the use of body shapes that may too thin or more realistic with the social outcomes and consider carefully the BMI of their target market.