Abstract
Research has consistently indicated that most children do not consume sufficient fruit and vegetables to provide them with a healthy, balanced diet. This study set out to trial a simple, low-cost behavioural nudge intervention to encourage children to select and consume more fruit and vegetables with their lunchtime meal in a primary school cafeteria.
Generated Summary
This study employed a cluster randomized design to assess the effectiveness of a low-cost behavioral nudge intervention aimed at increasing fruit and vegetable consumption among primary-age children in school cafeterias. Four primary schools in North Wales were randomly assigned to either an intervention or a control condition. The intervention schools underwent changes to their choice architecture, incorporating five behavioral nudges designed to encourage healthier food choices. Data on fruit, vegetable, vitamin C, fiber, and sugar consumption were collected at baseline and follow-up, with measurements taken over two days in each school to account for variability in children’s choices. The study aimed to determine the impact of these nudges on children’s consumption patterns, specifically focusing on fruit and vegetable intake, and to explore any associated changes in nutrient intake. The research utilized a validated photographic method to estimate individual children’s food consumption, enabling a detailed assessment of the intervention’s effects at both cohort and individual levels.
Key Findings & Statistics
- The study included 176 children, with 86 in the intervention and 90 in the control group.
- Significant increases were recorded in the intervention schools for children’s consumption of fruit, vitamin C, and fibre.
- No significant changes were observed in the control condition.
- Significant increases were found in the intervention condition for consumption of fruit (F (1, 86) = 17.21, p = .001), vitamin C (F (1, 86) = 11.39, p = .001), and fibre (F (1, 86) = 22.78, p = .001) from baseline to follow-up.
- No significant changes in consumption were identified in the intervention condition for vegetables (F (1,86) = 0.52, p = .473) and sugar (F (1, 86) = 3.52, p = .064) from baseline to follow-up.
- The intervention condition saw a significant increase in fruit consumption with a moderate effect size (r = .43), median consumption did not change in the control condition.
- Fruit consumption data:
- Baseline: Intervention median 7.88 g, Control median 12.35 g
- Follow-up: Intervention median 26.84 g, Control median 28.72 g
- Vegetable consumption data:
- Baseline: Intervention median 6.60 g, Control median 9.58 g
- Follow-up: Intervention median 9.58 g, Control median 12.58 g
- A post-hoc calorie intake analysis revealed that the two groups were matched at baseline (Intervention Median = 340.71, Control Median = 339.15, U = 3767, p = .760, r = -.02), however, calorie intake was not matched at follow-up (Intervention Median = 378.81, Control Median = 378.81, U = 3114, p = .025, r = -.17).
- In the intervention group, 46.5% of children increased fruit consumption, 44.2% showed no change, and 9.3% decreased consumption. In the control group, these figures were 18.9%, 63.3%, and 17.8% respectively.
- Vitamin C consumption increased significantly in the intervention condition (p < .001), levels of consumption were matched at follow up
- In the intervention condition, a significant increase in fibre consumption with a moderate effect size was observed over time (p < .001)
Other Important Findings
- The intervention involved five behavioral nudges: advertisements with colorful posters, attractive names for foods, food labels, attractive servings of fruit, and a change in the order of service to prioritize vegetables and fruit.
- The study utilized an independently validated digital photography method to estimate individual children’s consumption of fruit, vegetables, vitamin C, fiber, total sugars, and their overall calorie intake.
- The intervention was implemented in two schools over a period of three weeks, with data collection at baseline and follow-up.
- The intervention targeted children’s fruit choices and consumption.
- Daily selection of fruit pots ranged from 47 to 84 (out of a maximum of 132 students eating school dinners on any one day) over the course of the intervention.
- Levels of fibre were matched at follow-up.
Limitations Noted in the Document
- The study was limited by the lack of a control group and the absence of independently validated measures.
- The study acknowledges potential limitations related to the selection of nudges and the relatively low baseline fruit consumption, which might have created ceiling effects.
- The study recognizes that the effectiveness of the intervention might have been influenced by the specific nudges employed, with some potentially being more impactful than others.
- The study acknowledges that the intervention’s long-term sustainability could be influenced by factors such as the time commitment of catering staff and the need for additional resources to maintain the intervention.
- The study noted that changes to the choice architecture can only be expected to enable those children who already eat fruit and vegetables to make healthier day-to-day lunchtime choices, but nudges are unlikely to change the behavior of the remaining children who have not learned to like the target foods.
Conclusion
The study concludes that a low-cost intervention, by altering the choice architecture of school cafeterias, significantly increased fruit, vitamin C, and fiber consumption among primary-age children. The authors emphasize the implications for national and international strategies to improve children’s diets. The research highlights the effectiveness of simple yet effective behavioral nudge strategies in promoting healthier eating habits in schools. The authors state, “These results are the first to show that modest improvements to the choice architecture of school catering, and inclusion of behavioural nudges, can significantly increase fruit consumption, rather than just selection, in primary-age children.” The study underscores the importance of a close engagement with catering teams for intervention fidelity and sustainability, recognizing that their time commitment and any associated costs need to be carefully managed for wider implementation.