Potentially deceptive health nutrition–related advertising claims: The role of inoculation in conferring resistance

Abstract

Objective: This study sought to examine the efficacy of inoculation message treatments to facilitate resistance to health nutrition–related (HNR) commercial food advertising claims. Design: Data were collected across three phases extending across a 5-week period conducted over two semesters at a Midwest US university. A 2 × 3 between-subjects factorial design was adopted, with multivariate and univariate analyses being used to interpret the results. Setting: Pittsburg, USA. Method: Participants were emerging adult undergraduate students (aged 18–25 years) recruited from introductory communication courses. A total of 167 students participated in Phase 1 of the work, of whom 152 completed Phase 2 and 145 completed Phase 3 (resulting in an 86.8% retention rate). Among these, 45% were men. Results: The results indicated ( F(3, 129) = 9.83, p < .001, partial η2 = .18) that compared to control ( M = 5.20, standard deviation [ SD] = .84), participants who received an inoculation treatment experienced greater Phase 3 attitude strength ( M = 5.73, SD = .77) to the position that eating healthy food is necessary to maintaining a healthy life. Inoculated participants reported greater Phase 3 attitude certainty ( M = 77.15, SD = 19.21) for the above position than the control group ( M = 65.43, SD = 25.48). Inoculated participants held less favourable views towards the source of the HNR claims ( M = 4.80, SD = 1.18) relative to controls ( M = 5.73, SD = 1.36) and generated greater numbers of counter-arguments ( M = 3.90, SD = 1.74) compared to control groups ( M = 2.75, SD = 1.69), thus demonstrating resistance to persuasion. Conclusion: Inoculation was demonstrated to be an effective preemptive strategy against potentially deceptive HNR advertising claims. Hence, it may offer an effective strategy for helping to protect the health-conscious attitudes of emerging adults by providing resistance to the ‘pufferised’ appeals used by many commercial food advertisers.