Psychological manipulation mechanisms of false fitness and supplement information and public health risks: from information manipulation to behavioral decision-making

TL;DR

This study explores how false fitness and supplement claims on social media influence people's trust and purchasing decisions, potentially harming public health.

Contribution

The study reveals how interface cues and social validation signals, rather than content credibility, drive consumer behavior in health-related advertising.

Findings

High heuristic trust and perceived credibility are linked to lower risk perception and stronger purchase intention.

Risk perception negatively affects purchase intention, with a reliable indirect pathway through heuristic trust.

Persuasive impact is driven more by interface cues and social validation than by content credibility.

Abstract

This study investigates how false fitness and supplement claims shape judgment and behavioral intention through cue-based interface features and considers the implications for public health. In a randomized online experiment (N = 630), participants viewed simulated social-media advertisements that manipulated authority endorsement, scarcity framing, and conformity cues in a 2 × 2 × 2 design, along with a truthful control condition. Heuristic trust (M = 4.50, SD = 0.60) and perceived credibility (M = 6.54, SD = 0.44) were generally high and were closely linked to lower risk perception (M = 1.79, SD = 0.39) and stronger purchase intention (M = 5.02, SD = 0.68). Structural modeling showed that risk perception exerted a substantial negative association with intention, and the indirect pathway from heuristic trust to intention through risk perception was statistically reliable (indirect effect = 0.279, 95% CI [0.230, 0.329]). Regarding conditional effects, health literacy showed a consistent pattern in which higher literacy was associated with a stronger negative slope of risk perception on intention, although the interaction term was not statistically significant in the moderation model. Across conditions, persuasive impact was driven largely by interface cues and social validation signals rather than by the credibility of evidentiary content. These findings suggest that if persuasive cue structures remain unregulated in online health-related advertising, repeated exposure may gradually normalize low perceived risk and heighten purchase intention, posing longer-term challenges for consumer protection and public-health governance.