Abstract
To test the impact of a nudge strategy (dish of the day strategy) and the factors associated with vegetable dish choice, upon food selection by European adolescents in a real foodservice setting. Methods A cross-sectional quasi-experimental study was implemented in restaurants in four European countries: Denmark, France, Italy and United Kingdom. In total, 360 individuals aged 12–19 years were allocated into control or intervention groups, and asked to select from meat-based, fish-based, or vegetable-based meals. All three dishes were identically presented in appearance (balls with similar size and weight) and with the same sauce (tomato sauce) and side dishes (pasta and salad). In the intervention condition, the vegetable-based option was presented as the “dish of the day” and numbers of dishes chosen by each group were compared using the Pearson chi-square test. Multivariate logistic regression analysis was run to assess associations between choice of vegetable-based dish and its potential associated factors (adherence to Mediterranean diet, food neophobia, attitudes towards nudging for vegetables, food choice questionnaire, human values scale, social norms and self-estimated health, country, gender and belonging to control or intervention groups). All analyses were run in SPSS 22.0. Results The nudging strategy (dish of the day) did not show a difference on the choice of the vegetable-based option among adolescents tested (p = 0.80 for Denmark and France and p = 0.69 and p = 0.53 for Italy and UK, respectively). However, natural dimension of food choice questionnaire, social norms and attitudes towards vegetable nudging were all positively associated with the choice of the vegetable-based dish. Being male was negatively associated with choosing the vegetable-based dish. Conclusions The “dish of the day” strategy did not work under the study conditions. Choice of the vegetable-based dish was predicted by natural dimension, social norms, gender and attitudes towards vegetable nudging. An understanding of factors related to choosing vegetable based dishes is necessary for the development and implementation of public policy interventions aiming to increase the consumption of vegetables among adolescents.
Generated Summary
This study investigated the impact of a nudge strategy, specifically the “dish of the day” approach, on vegetable dish choices among European adolescents in real-world foodservice settings. The research employed a cross-sectional, quasi-experimental design, conducting experiments in restaurants across Denmark, France, Italy, and the United Kingdom. A total of 360 adolescents aged 12-19 years were divided into control and intervention groups. The intervention group was presented with a vegetable-based dish as the “dish of the day,” and the study assessed whether this strategy influenced their meal selections compared to the control group, where the strategy was not used. Data collection involved observing meal choices and analyzing potential factors associated with the selection of vegetable-based dishes. The study also explored the association between the choice of vegetable-based dishes and factors such as adherence to the Mediterranean diet, food neophobia, attitudes toward nudging for vegetables, responses on a food choice questionnaire, human values, social norms, and self-estimated health. Statistical analyses included Pearson chi-square tests and multivariate logistic regression to identify determinants of vegetable dish choice.
Key Findings & Statistics
- In Denmark, the intervention showed no significant difference (p = 0.80) in vegetable dish choice between the control and intervention groups. Similarly, in France, the nudging strategy did not significantly impact vegetable dish selection (p = 0.80).
- In Italy, the p-value for the intervention’s effect on vegetable dish choice was 0.69, indicating no significant difference.
- The United Kingdom also showed no significant impact of the nudging strategy (p = 0.53) on vegetable dish selection.
- The mean age of the adolescents in the study was 14.8 years (SD 0.85) in Denmark, 17.1 years (SD 1.17) in France, 15.4 years (SD 0.87) in Italy, and 17.1 years (SD 0.96) in the UK.
- The percentage of females in the sample was 48.8% in Denmark, 48.7% in France, 40.0% in Italy, and 45.7% in the UK.
- In Denmark, 77.8% of the control group chose meat balls compared to 72.0% in the intervention group.
- In France, 73.4% of the control group selected meat balls compared to 77.4% in the intervention group.
- In Italy, 66.7% of the control group chose meat balls compared to 62.0% in the intervention group.
- In the UK, 50.0% of the control group chose meat balls compared to 56.5% in the intervention group.
- Adherence to the Mediterranean diet was assessed through a 14-point scale, and food neophobia was evaluated through a 10-point scale.
- The natural dimension of the food choice questionnaire was positively associated with vegetable-based dish choice (OR = 2.71, p = 0.01).
- Social norms were positively associated with choosing the vegetable-based dish (OR = 1.16, p = 0.03).
- Attitudes towards vegetable nudging were also positively associated with choosing vegetable-based dishes (OR = 1.05, p = 0.03).
- Being male was negatively associated with choosing the vegetable-based dish.
Other Important Findings
- The “dish of the day” strategy did not significantly influence the choice of vegetable-based dishes among adolescents in the study’s conditions.
- The natural dimension of the food choice questionnaire, social norms, and attitudes towards vegetable nudging were positively associated with choosing the vegetable-based dish.
- Being male was negatively associated with choosing the vegetable-based dish.
- In the univariate analysis, the health (OR: 3.30, p = 0.01), weight (OR: 1.64, p = 0.01), and natural (OR: 2.71, p = 0.01) dimensions of the food choice questionnaire were significantly associated with the choice of a vegetable-based dish.
- In the univariate analysis, the power dimension of the human values scale was negatively associated with the choice of a vegetable-based dish (OR: 0.74, p = 0.03).
Limitations Noted in the Document
- The study’s sample sizes, particularly in the UK, Denmark and Italy, were slightly below the target, which could have influenced the statistical power.
- The study offered popular alternative meat dishes as competition, potentially weakening the effect of the nudge.
- The study was conducted in diverse environments (schools, culinary schools, and colleges) which may have affected the results.
Conclusion
The study’s findings suggest that the “dish of the day” nudging strategy was ineffective in encouraging adolescents to choose vegetable-based meals in the tested settings. The choice of vegetable-based dishes was significantly predicted by factors such as the natural dimension of food choice, social norms, gender, and attitudes towards vegetable nudging. The research highlights the importance of understanding the factors that influence food choices among adolescents to develop and implement effective public health interventions. The study emphasizes the need for further research to explore alternative or combined nudging strategies, particularly targeting males and utilizing interventions in social settings to promote vegetable consumption among adolescents. The use of choice architecture to modify food choices and encourage healthier eating habits in the population has gained increasing interest, with the primary goal of making the healthier choices the easiest option. The results show the significance of the natural dimension, social norms, and attitudes towards vegetable nudging in the selection of vegetable-based dishes. The study indicated that boys were less likely to choose vegetable dishes. These conclusions could be used as crucial tools in the development and application of public policies to encourage the consumption of vegetables and cut down the intake of meat among adolescents. The integration of interventions to increase vegetable intake should consider both the broader social context and the characteristics of the adolescents to maximize impact.