Lay theories and consumer perceptions of dietary supplements

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Department or Administrative Unit


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Consumers lack awareness and concern of potential adverse reactions, interactions, and inappropriate usage associated with dietary supplements. The lack of strict governmental regulation of supplements accompanied by consumers' lack of knowledge often results in them relying on ordinary lay (naïve) beliefs and theories when making supplement‐based decisions. We use an accessibility–diagnosticity framework to explore the impact of lay theories/beliefs on consumers' perceptions and judgments of dietary supplements. Two experiments prime two lay theories relevant to dietary supplement decision making: “less is more” (LIM: Study 1) and “no‐pain no‐gain” (NPNG: Study 2). Supplement form (single‐ vs. multi‐ingredient) is also manipulated in both studies, and Study 2 includes a Food and Drug Administration disclaimer intervention. Findings show that when a LIM lay theory is primed (Study 1), supplement form is a diagnostic cue. Specifically, consumers perceive that multi‐ingredient supplements possess more severe adverse side effects compared with single‐ingredient supplements. In the presence of an NPNG mindset (Study 2), supplement form was not diagnostic in the decision process, and a disclaimer intervention that draws attention to the lack of government regulation and testing of supplements was ineffective at influencing perceived side effect severity and attitude. The data confirm that lay theories impact dietary supplement decision making and that the observed effects are consistent with an accessibility–diagnosticity framework. Implications for public policy are also discussed.


This article was originally published in Journal of Consumer Behaviour. The full-text article from the publisher can be found here.

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Journal of Consumer Behaviour


© 2019 John Wiley & Sons, Ltd.