Pathways to healthy and sustainable diets: identifying facilitators, barriers and unintended consequences of switching to a more plant-based diet
Project Lead
Challenges
Generally, diets in Scotland are unhealthy and damaging to the environment. One solution is moving the population to more sustainable diets that are healthy and have a low environmental impact. For instance, a more plant-based diet, which comprise only small amounts of meat. Plant-based diets can have multiple health benefits when they include more whole foods such as fruit, vegetables, pulses, nuts, and whole grains. These diets typically have a lower environmental impact than meat-heavy diets.
Sustainable diets can have multiple co-benefits for health and the climate, which line with the Scottish Dietary Goals and Scottish Government emissions reduction targets to net zero by 2045. However, little is known about the type of food and meals people eat in place of meat and how it might change an overall diet. It can’t be assumed it will always be healthier. Hence, we need to be cautious about what we eat in place of meat. Plant-based convenience foods are increasingly available, but many are classified as highly processed which tend to be high in salt, sugar and fat, and if consumed regularly, could have negative consequences for health and the environment.
To support the right sort of dietary change, we need to understand barriers – both those people perceive and those they experience in the real world. While access and affordability are commonly cited barriers, social and cultural aspects of food choices are often overlooked, including the desire for convenience and familiarity. Understanding attitudes and personal, social, and situational factors driving or inhibiting the adoption of a more plant-based diet is critical for the development of policy interventions to change consumer behaviours and consumption patterns to create a healthier population and a more sustainable food system.
Questions
Solutions
The overarching aim of this project is to identify potential pathways to achieve healthy and sustainable diets and how to avoid unintended consequences in changing diets.
This project is extremely timely and critical as the need to improve diets is pressing. However, it is essential that shifts to more plant -based diets and reduction in meat do lead to improved health and environmental sustainability, since once established it could be challenging to reverse. The depth of evidence from this project supports the development of policy-related interventions and guidance for dietary recommendations for sustainable diets.
Perceived barriers and facilitators to eating a more plant-based diet
We are using multiple methods, including surveys and focus groups, to study the perceptions of the barriers people have towards changing diets and their lived experiences of switching to a more plant-based diet and eating less meat. We explore personal, social, and situational perspectives to generate ideas for facilitating change in diverse populations. We are also exploring the types of policy and intervention options that may be most effective in helping people eat more sustainable diets.
Experience of reducing meat consumption and real barriers to dietary
We are observing how perceived barriers to switching to a more plant-based diet play out in real life when people try to reduce their meat consumption in a free-living environment. We are conducting a mixed-methods trial where habitual meat eaters introduce three meat-free days a week into their diet and will observe through the lived experience, the challenges and facilitators they encountered. The findings will inform the development of interventions that can overcome practical barriers and facilitators while avoiding unintended consequences for health or the environment.
Contextual barriers and facilitators to healthy and sustainable diets
This project quantifies how the eating context (time, location, company) influences the decision to eat meat or meat-free meals. We explore what else might change in a meal if meat is reduced using the nationally collected dietary intakes data (National Diet and Nutrition Survey). The data covers a representative sample of the population in Scotland and will allow comparisons between socio-economic groups. The findings provide a more in-depth understanding of context and consequence of reducing meat consumption.
Household purchasing habits of meat and plant-based foods and meals
We are identifying whether and what foods replace meat if meat purchases decrease in a household. Using data collected over time, we are building a picture of household-level changes in food purchasing behaviours. We also explore the potential external factors that may affect purchasing and will learn whether people changing one item in their food basket (meat or plant-based meat alternatives), trigger unexpected changes elsewhere.
Project Partners
Progress
2023 / 2024
During our second year of research we have been exploring public attitudes towards dietary changes and practical steps that could support a shift toward sustainable diets.
Exploring Attitudes Toward Meat Consumption
We conducted an online survey of 1,590 adults across Scotland to understand meat consumption habits, interest in reducing meat intake, and perceived barriers. Our findings show that most participants eat meat frequently (around five days or more each week), but that a significant portion of people —about a third—are considering cutting back in the near future. Those inclined toward reducing meat consumption believe that policy changes affecting the cost and availability of meat alternatives would be the most supportive, while those less open to change prefer policies that improve the availability of plant-based options. Across all respondents, strategies around passive information, things like celebrity endorsements or information flyers were rated as the least impactful.
In addition to our survey, we have held focus groups across the North East of Scotland with both adults and young people to delve into what people know about sustainable diets and their attitudes toward reducing meat intake. Initial insights reveal that many adults know that there are environmental impacts of food choices, but some people did question the scale of these effects compared to other. When people talked about environmental impacts, they often thought about the physical environment (e.g., packaging, plastics and waste) more than climate. The willingness to cut down on meat varies, often influenced by socioeconomic factors, with more affluent groups more inclined to reduce than less affluent groups.
Social and Situational Influences on Dietary Change
We completed a pilot for our "Lived Experience of Sustainability in Scotland Meat" (LESS Meat) project. The aim is to observe real-world experiences and obstacles faced by people attempting to have three meat-free days each week. This study will help us to understand the sorts of daily challenges and motivations of people as they try to incorporate more plant-based meals into their routines. This pilot project will help to inform how we conduct the full study.
Patterns in Meat and Non-Meat Meals
Analysis of diet data from the National Diet and Nutrition Survey highlights differences in meal composition between meat-based and non-meat meals. Evening meals, typically the most substantial meal for many, often include meat. Interestingly, meal structure varies by the type of meat – compared to other meats, beef is more often paired with pasta, poultry with rice, and non-meat meals with bread. These meal composition patterns have implications for both environmental impact and nutritional quality, as non-meat meals are less likely to include vegetables or at least smaller portions when vegetables are present.
Knowledge Exchange and Outreach
We have been busy engaging in various knowledge exchange and outreach activities. This includes presenting our findings to local organizations, national policymakers, and international conferences. We have had lots of interesting conversations and even some ideas for new work on looking how our food choices are shaped by the food environment.
2022 / 2023
This project has six objectives which is being collectively addressed by four subprojects (S). The approach to this project is therefore:
Objective 1: to identify perceived and real barriers to switching to a more plant-based diet (S1, S2 and S3)
Objective 2: to find potential facilitators to support dietary change (S1 and S2)
Objective 3: to explore meat eaters' lived experience of eating less meat (S2)
Objective 4: to characterise the foods and meals eaten and purchased in place of meat (S2 and S4)
Objective 5: to estimate the nutritional and environmental impact of dietary change (S2 and S4)
Objective 6: to ascertain personal, social and situational factors influencing dietary change (S1, S2 and S3)
Subproject 1: We have designed and launched a questionnaire to survey public understanding about reducing meat consumption and eating a more plant-based diet. This survey was run on the Qualtrics platform and data will be collected for a representative sample of 1,500 people in Scotland. Questions include beliefs around food and the environment, willingness to change diets and attitudes towards different policies meant to encourage dietary change. Pilot data suggest little has changed in public understanding of 'sustainable diets'.
Focus groups have also been incorporated into this subproject, in order to gain a more in-depth understanding of relationships between food and the environment. Focus groups will be run with both adults and young people and will be repeated in similar populations to assess if attitudes have changed. Two adult focus groups have been run in this year. The young people focus groups will start in Year 2 due to delays in gaining permissions, holidays and school strikes.
Subproject 2: An eight-week trial has been designed in which people will be asked to record their experiences of trying to reduce their meat consumption to only four days a week, while continuing with their normal lives. Some details shall be informed by the focus groups and survey.
Subproject 3: We are analysing the cross-sectional National Diet and Nutrition Survey (NDNS) data that show a year-on-year decrease in average meat consumption. A number of novel methods have been used to look at these data, including network analysis to examine how food items are consumed together and substitute made in the whole diet, not just single food swaps. Early analyses suggest that there are no direct replacements for red meat.
Subproject 4: Although not due to start until Year 3, Kantar data has been purchased this year and many of the methods to understand meals (S3) are applicable to understanding food purchases (S4). Therefore, we have analysed these data alongside the consumption data where questions about substitutions of meat for other foods overlap. Unlike consumption data, meat purchases do not appear to decrease on average.
Impact: The results of this project will inform multiple stakeholder groups about the current beliefs and attitudes of people in Scotland with regards to dietary changes, and what needs to be considered in the development of policies, including the Good Food Nation Act, to encourage dietary change. Analysis of the large datasets (NDNS and Kantar) is going beyond exploring the concept of simple swapping of food items and exploring the impact of reducing meat consumption on the whole diet. This is particularly important as people rarely simply switch just one food in a meal, more often the structure of the whole meal changes. Hence, this approach gives a more accurate understanding of what will happen to the nutritional quality of the diet and the environmental impacts when foods such as meat are reduced in the diet.
Previous Projects
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Food Culture and Dietary Choice
This research targets a number of complementary, interdisciplinary strategies to support changes in food culture, social norms and dietary choices towards ‘sustainable and healthy balanced diets’. Socioeconomic and behavioural approaches will be applied to characterise factors affecting dietary choice and behaviours in different population groups and life-stages, particularly cultural influences. The aim is to explore the potential benefit of innovative interventions to change dietary habits.