Abstract
Food choices are often driven by impulsive tendencies rather than rational consideration. Some individuals may find it more difficult resisting impulses related to unhealthy food choices, and low self-control and high impulsivity have been suggested to be linked to these behaviors. Recent shifts have been made towards developing strategies that target automatic processes of decision-making and focus on adjusting the environment, referred to as nudging interventions. Therefore, the purpose of this study was to investigate the effect of impulsivity traits on food choices within a nudging intervention (increased perceived variety). A total of 83 adults participated in an experimental study consisting of a self-service intelligent buffet. Impulsivity traits were measured using the UPPS-P impulsivity scale. General linear models were fitted to evaluate the effect of the five impulsivity traits on the difference of salad consumption (g) between the control and intervention situations. Results showed that impulsivity does not affect food choices in this nudging situation, suggesting that nudging works independently of the participant’s impulsivity score. Results also showed a significantly higher consumption of salad in the nudging versus the control setting (17.6 g, p < 0.05), suggesting that nudging interventions can be effective in significantly increasing total vegetable consumption across the whole impulsivity scale.
Generated Summary
This research investigates the effect of impulsivity traits on food choices within a nudging intervention, specifically focusing on increased perceived variety. The study employed a one-factor experimental design, comparing a control setting with a nudging setting in which the presentation of mixed salad components was altered to increase perceived variety. A total of 83 adult participants were involved, with impulsivity traits measured using the UPPS-P impulsivity scale. The primary methodology involved fitting general linear models to assess the impact of five impulsivity traits on salad consumption differences between the control and intervention scenarios. Data was collected at the Evaluation Lab in the Department of Food Science at the University of Copenhagen, Frederiksberg campus, during a free lunch at a self-service buffet. Participants were not informed about the specific purpose of the study. The study lasted a total of four days spread over three weeks. Data analysis included descriptive statistics, mixed model ANOVA, and general linear regression models to test associations between impulsivity traits and salad consumption differences. The aim was to determine whether impulsivity traits affected food choices within the nudging intervention and if nudging could effectively increase vegetable intake.
Key Findings & Statistics
- A total of 83 participants were obtained, with a 16% dropout rate.
- The sample consisted mainly of females (70%).
- Participants were mostly students (84%), with the majority completing a bachelor’s degree (63%).
- Concerning diet, more than half of the sample were omnivores (55%), followed by flexitarians (24%) and vegetarians (13%).
- Impulsivity scores showed higher scores in the “sensation seeking” trait (mean = 2.8) and lower impulsive scores in the “lack of premeditation” trait (mean = 1.8).
- The scores obtained for the self-reported hunger were similar at both the first and second visit (mean of 3.5 and 3.8, respectively).
- Exposure to the nudge significantly increased salad consumption compared with the control (17.6g, p = 0.03).
- In mixed methods ANOVA, BMI affected only salad consumption (p < 0.01), while gender influenced the models for the remaining meal components consumption, total consumption, and total Kcal, but did not influence salad consumption.
- Differences in salad consumption had both positive and negative values, signifying that our nudging design was effective on some participants (those with positive values), but also had an opposite effect on other participants (those with negative values).
- None of our population sample scored high (score of 4) for the traits of Lack of Premeditation, Lack of Perseverance, and Positive Urgency.
- A few participants scored high in the Negative Urgency and Sensation Seeking trait.
- No participants scored low (score of 1) in the Sensation Seeking trait.
- The study showed that increasing perceived variety significantly increased the amount of salad consumption by 17.6 g (p = 0.03), but it did not significantly decrease any of the other meal component consumption (pasta, vegetable or meat sauces).
- No significant difference was found in total intake (g) or total energy intake (kcals) between the two settings.
Other Important Findings
- Results showed that impulsivity does not affect food choices in this nudging situation, suggesting that nudging works independently of the participant’s impulsivity score.
- The study found that increasing perceived variety significantly increased the amount of salad consumption by 17.6 g (p = 0.03).
- No significant association was found between the designed nudge and any of the impulsivity traits (Table 3); therefore, the hypothesis was rejected.
- The ibuffet used was able to record the precise quantities of food served by each participant.
Limitations Noted in the Document
- The sample population was not generalizable as it consisted mainly of students and females.
- The study’s effect size was smaller due to the weaker difference in salad consumption.
- The poor choice of serving utensils used for the different salad components during the nudge setting (regular tablespoons).
- Participants might have been conscious about being evaluated, possibly affecting their intake and influencing the results.
- The fact that food choice does not necessarily equate to food consumption, as the total amount of self-served meal components was measured.
Conclusion
The study’s primary objective was to assess the impact of UPPS-P impulsivity traits on food choices within a nudging setting. The findings indicated that nudging, in this case, increasing the perceived variety of vegetables, increased salad consumption regardless of participants’ impulsivity scores, suggesting that the nudging intervention’s effect was independent of impulsivity traits. The study’s results also indicate that increasing perceived variety can significantly increase total vegetable consumption in a student population. It suggests that it may not be necessary to design specific nudging interventions tailoring to people with higher levels of certain impulsive traits (negative urgency and lack of perseverance), but further studies are needed to validate our results. The findings support the notion that nudging interventions can be effective in promoting healthier eating behaviors across diverse levels of impulsivity. The study’s findings have implications for public health strategies aimed at improving dietary habits, indicating that interventions focusing on environmental adjustments might be successful regardless of individuals’ impulsivity levels. Future studies should focus on exploring different measures of impulsivity, and potentially combine various interventions.