Effect of health-promoting messages in television food commercials on adolescents' attitudes and consumption: A randomized intervention study.

Abstract

Introduction: The HAVISA plan is a Spanish government's policy for the promotion of healthy lifestyles via health messages in television food advertisements. This study evaluated the positive or negative impact (health halo effect) of health messages on food choices and predisposition towards healthy habits of Spanish adolescents. Methods: Randomized controlled study in 11-14 years old adolescents. The intervention group watched television advertisements for unhealthy foods with HAVISA health messages, while the control group watched the same advertisements without them. A self-administered questionnaire measured participants' attitudes towards the products advertised, to diet and physical activity, and recognition of messages. Afterwards they chose between fruit and unhealthy snacks. The differences between the two groups were then compared. Results: A total of 27.2% of the control group versus 29.6% of the intervention group chose fruit (p = 0.54). Both groups displayed high desire for (7.24 vs. 7.40, p = 0.29) and intention to consume (6.67 vs. 6.73, p = 0.63) the unhealthy products advertised. There were no differences in perceived healthiness of these foods (4.11 vs. 4.19, p = 0.74), or perceived importance of a healthy diet (3.17 vs. 3.12, p = 0.55) or physical activity (4.53 vs. 4.51, p = 0.73). Desire for vegetables (2.49 vs. 2.66, p = 0.08) and fruit (3.15 vs. 3.30, p = 0.09) were higher in the intervention group, but the differences were not significant. Only 47.6% of participants noticed the presence of health messages; of these, 31% correctly recalled their content. Conclusion: HAVISA health messages changed neither the attitudes nor immediate eating behaviors of adolescents. There was no immediate healthy-lifestyle promoter or adverse health halo effect, probably due to the messages' low prominence. Further research should evaluate the long-term effect of repeated exposure to health messages.