Understanding, promoting and predicting sustainable diets: A systematic review

Understanding food choice: A systematic review of reviews

The topic of consumer food choice has received much attention among researchers and stakeholders within the food industry. However, in order to better facilitate food consumption towards a more sustainable direction, we need increased knowledge and understanding of factors that influence consumers' food choice. This study is a systematic review of reviews conducted between 2017 and 2021, summarising and synthesising reviews on food choice. The aim is to provide an update of the current knowledge on consumer food choice, point out what is already known, and identify knowledge gaps to enable a prioritisation for future research. The analysis highlights decisive factors in food choice, i.e. product, available information, price, context, personal and group influences and sensory perceptions. The synthesis of findings follows a socioecological model, integrating four different levels of the social and environmental systems: the physical food environment, the social and community level, interpersonal relations and, finally, individual characteristics such as psychological and behavioural factors. Results show that behavioural patterns, influenced by strong informal institutions, such as culture and norms, can be difficult to break; for example, changing into more sustainable food behaviour. The findings suggest that more interdisciplinary research and studies in real-life settings are needed to grasp the complexity of food choice. This would allow for us to better understand consumers as social beings shaped by, among other things, the physical environment, social interactions, and culture.

Characteristics of built food environments associated with alternative protein food choices: a systematic review

BACKGROUND

This systematic review contributes to the understanding of the characteristics of built food environments that may be associated with choices of alternative protein foods (APF). Using the built food environment typology proposed by Downs et al., we investigated various environmental structures (e.g., supermarkets, other retailers, farmers' markets, restaurants, schools, and online vendors) and the characteristics that may facilitate or hinder consumers' choices. For example, facilitators and barriers may refer to the physical characteristics of environmental structures, food presentation practices, the organizational strategies or policies operating in the setting, or the actions that retailers or consumers engage in while selling, serving, choosing, trying, or purchasing APF in these environmental structures.

METHODS

A systematic review (PROSPERO database preregistration; no. CRD42023388700) was conducted by searching 13 databases for peer-reviewed journals focusing on the fields of economics and business, agriculture, medical sciences, and social sciences. Data searches, coding, and quality evaluations were conducted by at least 2 researchers. A total of 31 papers (36 original studies) were included. The risk of bias was evaluated with the Joanna Briggs Institute quality evaluation tool, with 24 publications presenting low risk of bias.

RESULTS

The findings indicate that perceived and actual availability facilitate consumers' APF choices across a built food environment. Several barriers/facilitators were associated with APF choices in specific types of built food environments: the way food is presented in produce sections (supermarkets), consumer habits in terms of green and specialty shopping (grocery stores), and mismatches among retailer actions in regard to making APF available in one type of food environment structure (e-commerce) and consumers' preferences for APF being available in other food environment structures (supermarkets, grocery stores). The effect of a barrier/facilitator may depend on the APF type; for example, social norms regarding masculinity were a barrier affecting plant-based APF choices in restaurants, but these norms were not a barrier affecting the choice of insect-based APF in restaurants.

CONCLUSIONS

Addressing barriers/facilitators identified in this review will help in developing environment-matching interventions that aim to make alternative proteins mainstream.

TRIAL REGISTRATION

PROSPERO database registration: #CRD42023388700.

Gender and cross-country differences in the determinants of sustainable diet intentions: a multigroup analysis of the UK, China, Sweden, and Brazil

Introduction

Gender differences have been identified in both the engagement in and the determinants of sustainable diet behaviours. However, as engagement in pro-environmental behaviours varies across countries, the consistency of gender differences could follow similar patterns. Understanding the factors underlying gender and country differences in diet intentions is important for determining how to promote sustainable diets in different populations.

Methods

Using survey data from the UK, China, Sweden and Brazil (N=4,569), this paper examines the influence of subjective norms, diet-related identity, perceived status of meat consumption, environmental identity and environmental concern on sustainable diet intentions. Multigroup analysis was used to explore gender and country differences in the influence of these variables, and whether gender differences were consistent across the four countries.

Results

The findings show that there are gender differences in the influence of diet-related identity and perceived status of meat consumption, as well as cross-country differences in all factors except subjective norms. Holding a strong diet-related meat identity negatively affected sustainable diet intentions in all groups. Crucially, however, gender differences are not consistent across countries.

Discussion

These results suggest that individuals' intentions to engage in sustainable diet behaviours are influenced by nationally unique gender associations.

Who has a high level of food literacy, and who does not?: a qualitative study of college students in South Korea

BACKGROUND/OBJECTIVES

Unhealthy food choices among young adults are common globally, and the incidence of chronic diseases, such as obesity, is rising. Food literacy (FL) is important for improving and maintaining individual health in a rapidly changing food environment and can form the basis for following a sustainable diet. Therefore, it is essential to improve FL among young adults, particularly college students, who are in the formative years of their lifelong food habits. This study examined the facilitators and barriers of FL and related dietary behavior among college students in South Korea.

SUBJECTS/METHODS

This study recruited 25 college students with different residence types using convenience and snowball sampling. In-person, telephone, and video interviews were conducted from March to November 2021. The interview data were analyzed using framework analysis based on the socio-ecological model.

RESULTS

At the individual level, prior good experiences with food were the most frequently mentioned facilitator. In contrast, the major barriers were a lack of knowledge, financial hardship, irregular schedules, and academic stress. At the interpersonal level, the influences of family and peers, such as early exposure to healthy eating habits and opportunities to have easy accessibility to farms and farming, are major facilitators, but the lack of a sense of community was the major barrier. At the environmental level, the major barriers were unfavorable food environments at home and in neighborhoods, such as the absence of kitchens in housing and large packaging of produce at markets.

CONCLUSIONS

Many factors affected the students' FL and related healthy eating practices. These findings suggest that a campus-based FL program should be developed by reflecting on these facilitators and barriers.

Relationships Between Three Eating Behaviors and Nine Motives for Food Choices Among Brazilian Adults: A Structural Equation Model

We examined the relationships between three eating behaviors and nine motives underlying food choices made by Brazilian adults. Using participant responses to the short version of the Three-Factor Eating Questionnaire and the Food Choice Questionnaire, we investigated eating behaviors (cognitive restriction, uncontrolled eating, and emotional eating) and motives for food choices (health, mood, convenience, sensory appeal, natural content, price, weight control, familiarity, and ethical concern). We used a structural equation model to test relationship pathways (β), with eating behaviors as independent variables and motives for food choices as dependent variables. Participants were 1297 individuals (69.5% female) with a mean age of 25.0 years (SD = 5.8). We confirmed the validity and reliability of the questionnaires in this sample. Restrictive eating behavior was significantly related to motives of health (β = .415), mood (β = .127), natural content (β = .364), weight control (β = .681), and ethical concern (β = .161). Emotional eating behavior was related to motives of mood (β = .277), health (β = -.137), and natural content (β = -.136). Uncontrolled eating behavior was related to motives of convenience (β = .226), sensory appeal (β = .121), price (β = .153), and familiarity (β = .090). We believe these findings can now help design future research and clinical interventions for managing people's risky eating behaviors and promoting beneficial food choices.

Consumer attitudes and behaviors toward more sustainable diets: a scoping review

There is an urgent need to move toward more sustainable diets. Although this will require radical and systemic changes across food systems, altering consumer ideologies and practices is essential to garner support for such actions. In this scoping review, the evidence on consumers' attitudes and behaviors toward more sustainable diets is synthesized and a range of factors, considerations, and proposed strategies are presented that can contribute to building the societal-level support for urgent and systems-level changes. The findings suggest that consumers, insofar as they are interested in sustainability and have the capacity to engage with the concept, primarily approach the concept of sustainable diet from a human health perspective. However, the interconnectedness of human health and well-being with environmental health is poorly understood and under-researched in the context of consumer behaviors and attitudes toward sustainable diets. This highlights the need for (1) sustained efforts from public health professionals to encourage a realignment of the term sustainable diet with its multidimensional meaning by championing an ecological public health approach in all efforts aimed at promoting more sustainable consumption, from awareness raising to policy development; (2) a broader research lens focused on the multidimensional concept of sustainability in the literature exploring consumer attitudes and behaviors; and (3) the development of multidisciplinary, clear, and evidence-based sustainable-eating messages, including holistic sustainable dietary guidance, to address knowledge gaps, minimize conflicting narratives, and build consumer agency. The findings contribute to understanding how support can be generated for the necessary structural and system-level changes required to support behavior change.

"I guess it's quite trendy": A qualitative insight into young meat-eaters' sustainable food consumption habits and perceptions towards current and future protein alternatives

As the market for sustainable food continues to expand, there is a need to understand how consumers' consumption habits and perceptions are changing. Targeting the younger populations is of interest as they arguably will shape the future of food. Therefore, the present study aimed to provide in-depth consumer insights on a range of topics from current consumption habits (i.e., meat reduction, plant-based meat/seafood (PBM/S)), towards future protein alternatives (i.e., cell-based meat/seafood (CBM/S), precision fermented dairy (PFD)). Online focus groups were conducted in the UK with meat-eaters (n = 38) aged 18-34. Codebook thematic analysis was applied using the Framework Matrix as a tool for data analysis. Key themes were presented using the COM-B model (Capability, Opportunity, Motivation), which identified areas of behavioural change. Results found a trend towards meat reduction, partially initiated by moving away from home and limited food budgets. Overall, participants acknowledged the environmental impact of food, but a notable knowledge gap was apparent when quantifying the effect, especially for dairy and seafood. Compared to PBM, few participants had tried PBS products, partially due to lower availability and familiarity. Enablers for PBM/S included convenience, positive sensory experiences and the influence of others, whilst barriers related to negative health connotations and over-processing. For CBM/S and PFD, animal welfare, curiosity and optimised nutrition acted as enablers, whilst barriers related to wider consumer acceptance, affordability and unnaturalness. In general, participants felt changing food consumption habits can have an impact on climate change and were optimistic about novel technologies supporting future protein transitions. Increasing public understanding around the environmental impact of food, especially seafood and dairy, and prioritising the affordability of sustainable food are suggested as intervention strategies to encourage sustainable food consumption.

Predicting the Adoption of a Sustainable Diet in Adults: A Cross-Sectional Study in Italy

Shifting food choices towards sustainability entails the analysis of dietary behavior determinants. This study aimed to explain and predict the intention to follow a sustainable diet and its adoption in a representative sample of adults (n = 838) in Italy. An online survey based on the theory of planned behavior (TPB) was developed. The adoption of a sustainable diet was measured as self-perceived behavior, adherence to the Mediterranean diet (MD), and food consumption frequencies. Psychometric analysis and correlations between attitude, subjective norms, and perceived behavioral control (PBC) with both intention and behavior assessments were evaluated. Structural equation models were used to test whether and to what extent attitude, subjective norms, and PBC explained intention and behavior. Significant associations were found between TPB constructs and the behavior measures underlining the main role of intention and PBC in affecting behavior. The applied TPB models explained behavioral intention at most (78%). The results suggested promising interventions in narrowing the attitude-behavior gap to encourage specific adult population groups in Italy to adopt virtuous food consumption habits. Beside the implementation of price mechanism strategies, educational initiatives to increase awareness about food and diet sustainability issues and the reinforcement of the perceived control on food consumption at the individual level are recommended.

Assessing the interlinkage between biodiversity and diet through the Mediterranean diet case

The adoption of healthy and sustainable diets, and the transition to sustainable food systems is of principal importance in order to counteract the double burden of climate change and non-communicable diseases. The Mediterranean diet (MD) has been widely recognized as a biodiversity and healthy nutrition resource to support sustainable development and food security. This study explored biodiversity in terms of food plants species, subspecies, varieties and races, and also addressed food-plant diversity differences between the MD and western-type consumption patterns. It was funded by the EU BioValue Project, aiming to promote the integration of underutilized crops into the food value chains. Using a two-stage scheme, data were selected from MEDUSA and Euro+Med databases (including 449 species, 2,366 subspecies, varieties, and races). Furthermore, 12 countries from North Africa and Europe were classified in two groups according to their sub-regional attributes and their traditionally most prevalent dietary pattern (MD or western-type diets). Statistical analysis showed that the mean of the majorly cultivated food plants in the MD was significantly higher than its counterpart in the Western-diet. Furthermore, no statistical difference was detected in the averages of native food plants between the MD group and the Western diet group, implying that the higher diversity in food plants observed in the MD seems to be attributed to crop utilization rather than crop availability. Our findings indicated the interlinkage between biodiversity and prevailing dietary patterns, and further underlined that biodiversity could constitute a prerequisite for dietary diversity, and hence nutrition security. In addition, this study demonstrated that diets and nutrition should be approached in a broader way within the context of both agro-food and ecological systems.

Public interest in food sustainability: an infodemiology study of Google trends data in Europe from 2010-2021

Understanding food sustainability and healthy diets public awareness is of utmost importance since consumers are the main drivers of global consumption patterns. Using Google Trends data, from 2010 to 2021, we aim to explore the temporal dynamics of food sustainability public interest across Europe and its association with interest in sustainability, healthy diet, Mediterranean diet (MedDiet), and flexitarianism. Public interest in food sustainability has increased and is positively associated with the interest in the topic of sustainability. With few exceptions, no general association between food sustainability and healthy diet or MedDiet interest were found. Consistent associations between food sustainability and flexitarianism were found across most of the European regions and countries. Despite the growing interest, only flexitarianism seems to be associated with food sustainability. Understanding consumers' interest in food sustainability is crucial for the transition towards healthy and sustainable diets and to define educational and behavioural interventions.

COVID-19 Changes Public Awareness about Food Sustainability and Dietary Patterns: A Google Trends Analysis

The COVID-19 pandemic has not only affected healthcare systems and global economies but also directly impacted food security and purchasing behaviors. The aim of this study is to investigate if COVID-19 has induced changes in public interest regarding Food Sustainability and healthy-sustainable dietary patterns across Europe and in European regions. A Google Trends search was performed using the search terms "Food Sustainability + Sustainable Diet + Sustainable Food" (grouped as "Food Sustainability") and the topics "Sustainability", "Healthy Diet", "Mediterranean Diet", and "Flexitarianism" for the years 2010 to 2022. Data were obtained for 12 countries in Europe. The trends in interest after the COVID-19 outbreak were forecast based on previous data. After the COVID-19 outbreak, an increase in Food Sustainability interest was observed and was higher than forecast based on the previous data. A significant interest increase in Sustainability was observed; nevertheless, this increase was smaller than the forecast increase. Mixed results were obtained for dietary patterns across European regions, yet, considering the mean interest for Europe, it seems that the COVID-19 pandemic outbreak dampened the interest in dietary patterns such as the Healthy Diet and Flexitarianism and promoted an interest in the Mediterranean Diet. Understanding consumers' beliefs and behaviors toward food choices is crucial for the transition towards sustainable diets, and definitions of educational and behavioral interventions are essential to this transition.

Healthy and Sustainable Food Shopping: A Survey of Intentions and Motivations

Objectives

To determine the relationship between sustainable and healthy food shopping behavior comparing general motivation with the immediate intention to act.

Method

We conducted an online survey of 144 staff at the Cork Institute of Technology, Ireland, using a questionnaire based on the Theory of Planned Behavior and the Self-Determination Theory to compute the Behavioral Intention score and the Relative Autonomy Index in relation to healthy and sustainable grocery shopping.

Results

The intention to shop healthy food was higher (p < 0.001, Cohen's d = 0.56) than the intention to shop in a sustainable way. A significant intention-action gap was observed for both healthy (p < 0.001, Cohen's d = 0.97) and sustainable grocery shopping (p < 0.001, Cohen's d = 1.78). While there was a significant correlation (p < 0.001) between the longer-term motivations to act in a healthy and sustainable way, this association was not significant (p = 0.16) for the more short-term Behavioral Intention scores.

Conclusion and Implications

Health was identified as a more important driver for dietary behavior compared to sustainability. While longer-term motivation shows a stronger correlation between healthy and sustainable grocery shopping, short-term intentions do not follow this pattern as strongly. A significant intention-action gap exists for both, which is stronger for sustainability than for health.

Effects of Perceived Benefit on Vitamin D Supplementation Intention: A Theory of Planned Behaviour Perspective

There are many factors that affect vitamin D supplementation, including those from the theory of planned behaviour (TPB); however, how the perceived benefit acts in the model remains unknown. In the current study, we tested the efficacy of the TPB and the impacts of the perceived benefit (PBE) in the model. The subjects were 287 customers who purchased vitD from pharmacies in major cities in Taiwan. A structured questionnaire was used to collect the data. t-tests, analysis of variance (ANOVA), regression analyses, and path analysis via SPSS and AMOS were used to analyse the data. The original TPB model explained 47.5% of the variance of intention with the three variables of attitude (β = 0.261), perceived behavioural control (β = 0.183), and subjective norms (β = 0.169). The model that incorporated PBE increased the explained variance to 59.7%, and PBE became the strongest predictor (β = 0.310) and a significant mediator linking attitude, subjective norms, perceived control (ANC) with supplementation intention. PBE and attitude were the two most important variables in predicting vitD supplementation intention. We suggest that updated information regarding dietary sources of vitD and its benefits should be included in health- or nutrition-related courses in education programs for the overall health of the nation.

Exploring adults' motives for food choice of sustainable diet components: a qualitative study in Tehran Metropolis

BACKGROUND

Todays, due to the impact of human food choices on increasing greenhouse gas emissions, water consumption and environmental degradation, there is a new approach about changing the pattern of food production and consumption, including sustainable food and nutrition system related to consumption. This study aimed to explore the components of a sustainable diet among the factors that affect people's food choices.

METHODS

This qualitative study was carried out using an in-depth interview with 33 individuals aged 30-64 years old living in different areas of Tehran. Data collection, data analysis and theoretical conceptualization were performed simultaneously. MAXQDA 10 software was used for managing and organizing the data.

RESULTS

In this paper, the findings are categorized according to the key components of a sustainable diet in five themes: "Health and Nutrition", "Food and Agriculture Security", "Environment and Ecosystems", "Markets, food trade and production chains", "social, cultural, and policy factors" were categorized. Meanwhile, the components of the "Health and Nutrition" domain had the highest contribution and the components of the two domains "food and agriculture" and "environment and ecosystems" had the lowest role based on the participants' perception in this study.

CONCLUSION

Considering to the low importance of the components of a sustainable diet in food choices of the community, promoting the individual awareness of sustainable diet components, clarifying the importance of food choices in creating environmental impacts and leading the national macro policies in the field food and nutrition toward sustainable diet goals are essential.

Choice Drivers for Quality-Labelled Food: A Cross-Cultural Comparison on PDO Cheese

This study aims at examining the consumers’ preferences and drivers affecting the choice of quality-labelled food products, i.e., protected designation of origin (PDO) labelled cheese. We applied the theory of planned behaviour (TPB) to analyse the purchase of Parmigiano Reggiano PDO and Comté PDO hard cheeses in Italy and France, respectively. A cross-sectional sample of 808 consumers (400 French and 408 Italian) completed a questionnaire. Structural equation modelling (SEM) indicated perceived behavioural control (PBC) and attitude to be significant predictors of intention to purchase PDO-labelled cheese in France and Italy. Subjective and moral norms affected intention in France. Intention significantly influenced the hard cheese purchase behaviour. The results confirm that the TPB model predicted the self-reported measure of behaviour more than the observed one, measured with a discrete choice experiment, in both countries. The TPB interrelationships varied between countries, suggesting that food systems operators and public authorities should carefully target their intervention to stimulate the demand of PDO-labelled products.