Are some comparative nutrition claims misleading? The role of nutrition knowledge, ad claim type and disclosure conditions

As the regulator of all national food advertising, the Federal Trade Commission (FTC) has expressed concern that consumers may be misled by certain comparative nutrient content claims in advertising. To help examine this issue, primary food shoppers were recruited and interviewed in three U.S. markets according to generally accepted procedures for advertising copy tests. The study employs a 2 (ad claim type) x 2 (nutrition knowledge) x 4 (disclosure type) between-subjects design using manipulated print advertisements. Misleading generalizations for absolute levels of sodium content beyond that of control ads are found for both specific and general nutrient content claims from experimentally manipulated soup advertisements Effects of certain ad disclosure types are found to be dependent on ad claim type and on nutrition knowledge levels. Conclusions from the study and implications for advertising practice and public policy are offered.