The link between meal sustainability perceptions and healthiness

By Vijay Kumar MalesuReviewed by Lily Ramsey, LLMDec 1 2023

In a recent study published in PLOS SUSTAINABILITY AND TRANSFORMATION, a group of researchers examined if the perceived association between meal sustainability and healthiness reflects reality and analyzed the impact of meal and individual characteristics on this perception.

Study: The “healthy = sustainable” heuristic: Do meal or individual characteristics affect the association between perceived sustainability and healthiness of meals? Image Credit: Jacob Lund/Shutterstock.com

Background 

One of the modern challenges is healthy and sustainable eating. Dietary decisions are largely influenced by individual understanding of foods' nature and health implications.

Although food sustainability consists of various dimensions, its ecological dimension stands out as the most important issue from the perspective of common sense. However, further research is needed. Although individuals frequently resort to “healthy equals sustainable” heuristics in choosing their foodstuff, such perceptions might not be directly associated with its true healthiness and sustainability.

Additionally, the influence of individual and meal characteristics on this heuristic is not well understood, requiring more investigation to determine how these factors affect food choice decisions in real-life contexts.

About the study 

The research was conducted in a university cafeteria, in Germany, which is popular among the university's 11,000 students and 2,400 staff members because of its location.

During the survey conducted in February 2020 the cafeteria offered a selection of four to five hot meals each day on various menu lines. Meal prices were subsidized for students, and it varied depending on the menu line and customer status.

In total, this survey covered six periods, which included a total of 29 different meals. Customers were given a paper questionnaire to fill out after purchasing and consuming their meals.

They left the completed questionnaires on their trays when they were done. The questionnaire asked participants to rate the healthiness and sustainability of their meals using a six-point Likert scale. It also collected information such as gender, age, and eating habits.

The researchers analyzed the data using NAHGAST algorithm’s standardized tool suite to calculate every meal's environmental sustainability and healthiness scores. The scores relied on ingredient type, preparation method, and environmental sustainability.

Mixed linear regression models were used to investigate the relationship between mean and self-perceived meal characteristics in individuals consuming mixed meals, with meals representing the second-level units and participants constituting the first level unit.

The study checked assumptions like normality, linearity, and absence of strong correlations among independent variables. Outliers were excluded, and data was group-mean centered or grand-mean centered as appropriate.

Initial analyses indicated a significant proportion of variance in perceived healthiness between meals, justifying the multilevel structure of the data. The models analyzed the correlation between perceived sustainability and healthiness, the effect of the discrepancy between actual healthiness and sustainability scores, the impact of meal characteristics such as content and nutritional indicators, and the influence of individual characteristics like gender, age, and eating style.

Essentially, the research looked at the interaction of real and perceived features of meals in relationship to sustainable and healthy dietary intakes among specific populations.

Study results 

The present study revealed that people’s perception of meal sustainability correlated with their view on healthiness.

Moreover, it was indicated that meal sustainability influenced the subjective assessment of meal health regardless of healthiness or environmental burden. The same trend was seen in most meals, suggesting that people generally assume that sustainable food is also healthy.

The study also delved into how personal characteristics play a role in shaping these perceptions. Factors like gender, age, and different eating habits (such as being vegan, vegetarian, gluten-free, lactose free, following energy limited diets, among others) were analyzed to see how they influence people's views on the healthiness and sustainability of meals.

It was interesting to note that while there were effects of perceived sustainability and certain eating styles (like vegetarianism) on how healthy meals were perceived, the interactions between these characteristics and perceived sustainability did not significantly impact.

This suggests that the connection between perceived healthiness and sustainability remains consistent across groups.

Age was one exception to this pattern. Older participants demonstrated a slightly stronger association between perceived sustainability and healthiness than younger participants, suggesting that age may influence reliance on the "healthy = sustainable" heuristic. However, other individual characteristics, such as gender and specific eating styles, did not significantly alter this relationship.

The study further investigated whether actual meal characteristics influenced this perception. The researchers considered actual meal healthiness, environmental sustainability, and whether the meal was plant-based or contained animal products.

They found that while plant-based meals were generally perceived as healthier than those with animal-based content, these actual meal characteristics did not significantly influence the "healthy = sustainable" association.

Conclusion

Lastly, the study revealed a strong and consistent association between perceived sustainability and health across various meals and demographic groups.

This association did not align with the actual healthiness and sustainability of the meals, indicating that consumers tend to use a heuristic approach when evaluating meal options.

The findings suggest that this heuristic is deeply ingrained and operates independently of actual meal characteristics or individual differences in demographics and eating styles.