Background: Healthy diets are crucial for maintaining overall wellbeing and reducing risk of obesity and related noncommunicable disease. Visual cues and primes are becoming popular implicit nudging techniques for promoting healthier consumption behaviours. The present review aimed to evaluate the effectiveness of these cues and primes for nudging consumption-related behaviours.
Methods: A comprehensive search was conducted in six electronic databases for experimental studies on the use of non-marketing-based visual cues and primes on food and/or beverage consumption. Sixty-three studies from 50 articles were included, resulting in 182 comparisons which were categorised into four groups for separate meta-analyses.
Findings: Preliminary analyses indicate that, overall, nudges effectively influence consumption-related behaviours. Healthy nudges increased healthy consumption in comparison to control and unhealthy nudge conditions. Unhealthy nudges increased unhealthy consumption compared to control conditions. The effectiveness of these nudges was moderated by study setting, participant weight, and characteristics of the dependent variable (e.g., type of behaviour assessed, type and healthiness of the outcome, and measurement of hypothetical versus real-stakes outcomes). Results also demonstrated that nudges not inherently related to health also significantly influenced consumption-related behaviours.
Conclusion: The present review supports the efficacy of visual cues and primes in eliciting changes in consumption-related behaviours, potentially helping to reduce rates of obesity and related conditions. The results indicate that different forms of nudges may be more appropriate in different circumstances. Further research is needed to thoroughly comprehend the underlying mechanisms of these nudging techniques to help design more effective interventions.