Abstract
Background Changing the food environment is an important public health lever for encouraging sustainable food choices. Targeting the availability of vegetarian main meals served in cafeterias substantially affects food choice, but acceptability has never been assessed. We examined the effects of an availability intervention at a French university cafeteria on students’ main meal choices, meal offer satisfaction and liking. Methods A four-week controlled trial was conducted in a university cafeteria in Dijon, France. During the two-week control period, vegetarian main meals constituted 24% of the offer. In the subsequent two-week intervention period, this proportion increased to 48%, while all the other menu items remained unchanged. Students were not informed of the change. Student choices were tracked using production data, and daily paper ballots were used to assess student satisfaction with the meal offer and liking of the main meal they chose (score range [1;5]). Nutritional quality, environmental impact, and cost of production of meal choices were calculated for each lunchtime. Food waste was measured over 4 lunchtimes during control and intervention periods. An online questionnaire collected student feedback at the end of the study. Results Doubling availability of vegetarian main meals significantly increased the likelihood of choosing vegetarian options (OR=2.57, 95% CI = [2.41; 2.74]). Responses of the paper ballots (n = 18,342) indicated slight improvements in meal offer satisfaction from 4.05 ±0.92 to 4.07 ±0.93 (p=0.028) and in liking from 4.09±0.90 to 4.13±0.92 (p < 0.001) during control and intervention periods, respectively. The end-of-study questionnaire (n=510) revealed that only 6% of students noticed a change the availability of vegetarian main meals. The intervention led to a decrease in the environmental impact of the main meals chosen, a slight decrease in nutritional quality, a slight increase in meal costs and no change in food waste. Conclusions Doubling availability of vegetarian main meals in a university cafeteria resulted in a twofold increase in their selection, with students reporting being more satisfied and liking the main meals more during the intervention
Generated Summary
This study investigates the effects of increasing the availability of vegetarian options on main meal choices, meal offer satisfaction, and liking within a French university cafeteria. A four-week controlled trial was conducted, with a two-week control period where vegetarian main meals constituted 24% of the offer, followed by a two-week intervention period where this increased to 48%. Student choices were tracked, satisfaction and liking were assessed using paper ballots, and nutritional quality, environmental impact, and cost of production of meal choices were calculated. The primary objective was to determine the impact of increased vegetarian availability on students’ main meal choices and to evaluate the acceptability of the intervention. The research also examined the effects on nutritional quality, carbon footprint, and cost of production. Statistical analyses included generalized linear mixed models to assess the impact of the intervention and the type of meal on students’ satisfaction and liking, with lunchtimes as a random effect.
Key Findings & Statistics
- Study Design: A four-week controlled experiment conducted in a French university cafeteria in Dijon.
- Participants: Data collected on 37,299 main meal choices over 17 lunchtimes, with an average of 2194 ± 324 students per lunchtime.
- Control Period: Vegetarian main meals constituted 24% of the offer.
- Intervention Period: Vegetarian main meals increased to 48%.
- Main Meal Choices: 18,094 main meal choices during the control period and 19,205 during the intervention period.
- Student Participation: 54% of students participated in the daily satisfaction and liking survey, totaling 18,342 responses.
- Vegetarian Main Meal Choices:
- Correlation between vegetarian meal availability and choice: r=0.97, p<0.001.
- Control period: 23% of participants chose vegetarian main meals.
- Intervention period: 45% of participants chose vegetarian main meals.
- Increase in vegetarian meal choices: OR = 2.57, 95% CI = [2.41; 2.74].
- Control period: 502 ± 135 vegetarian meals and 1760 ± 325 non-vegetarian meals per day.
- Intervention period: 945 ± 316 vegetarian meals and 1189 ± 397 non-vegetarian meals per day.
- Meal Offer Satisfaction:
- Slight increase in satisfaction: 4.05 ± 0.92 (control) to 4.07 ± 0.93 (intervention), p = 0.028.
- Meal Liking:
- Slight increase in liking: 4.09 ± 0.90 (control) to 4.13 ± 0.92 (intervention), p < 0.001.
- Food Waste: No significant change in food waste was observed during the intervention (p = 0.50).
- Nutritional Quality (FSA score): Decrease in nutritional quality from 4.71 during the control period to 4.93 during the intervention period for an average main meal (β = 0.25, t(37,298)=3.07, p = 0.002).
- GHGE: GHGE decreased from 1.34 kg CO2 eq in the control period to 1.06 kg CO2 eq in the intervention period for an average main meal (β = -0.24, t(37,298) = -17.6, p < 0.001), i.e., 560 kg CO2 eq saved per day for 2000 guests.
- Cost of Production: A slight cost increase from 0.95 € in the control period to 1.02€ in the intervention period for an average main meal (β = 0.08, t(37,298) = 20.3, p < 0.001), i.e., an increase of 140€ per day for 2,000 guests.
- Student Perception: Only 5.5% of students reported noticing a change in the availability of vegetarian main meals.
Other Important Findings
- The study found a strong correlation (r=0.97, p<0.001) between the availability of vegetarian main meals and the choice of these meals by students.
- The intervention led to a decrease in the environmental impact of the main meals chosen.
- The intervention resulted in a slight increase in meal costs.
- The average liking score for vegetarian main meals (4.01 ± 1.01) was slightly lower than that for non-vegetarian main meals (4.17 ± 0.85) (β=-0.14, t(17,421)=- 2.05, p=0.009).
- No effect of the interaction between the type of main meal (vegetarian or nonvegetarian) and the intervention of the study on the liking score (ß=-0.05, t(17,421)=-1.38, p=0.168), meaning that the vegetarian options chosen during the control and the intervention periods were similarly liked by the students.
Limitations Noted in the Document
- The study was limited by the number of strike actions which reduced the number of observed lunchtimes.
- Data collection relied on production and sales data, and liking and satisfaction scores were anonymous, lacking identification of individual-level changes in food choices.
- The study did not record what was available for whom at each time point during one lunchtime.
- The length of the study was limited to two weeks, and the sustainability of the observed effects over a longer duration is uncertain.
- The study was conducted in a single university cafeteria in France, which limits the generalizability of the findings.
Conclusion
This study successfully demonstrated the positive effects of increasing the availability of vegetarian main meals in a university cafeteria. The results indicate a strong association between the increased availability of vegetarian main meals and a corresponding increase in the selection of these options by students. The doubling of vegetarian options led to a significant rise in their selection, and the intervention was well-received by the students, as indicated by maintained or slightly improved satisfaction and liking scores. The study’s findings align with previous research, particularly those conducted in British university cafeterias, and highlight the practical implications for similar settings. The high acceptability of the intervention, with minimal negative feedback from participants, suggests that interventions focusing on altering the food environment are viable strategies. The observed reduction in the carbon footprint of main meals further supports the sustainability benefits of the intervention. A key strength of this study lies in its real-world setting and the high-quality data obtained from the student population. The study also reveals that there was no statistically significant increase in food waste during the intervention period. This research underscores that increasing the availability of vegetarian meals within university cafeterias is a straightforward and highly acceptable method to influence the choices of vegetarian main meals, thus promoting more sustainable food choices. Further research could explore different types of vegetarian options.