Our aim is to understand and analyse what people eat outside of the home. This evidence will create a current and comprehensive source of information about the out-of-home sector that can be used by stakeholders in this field. The evidence we gather will play a crucial role in Nesta's future projects by helping us identify key trends, interventions or opportunities to focus on where there is greatest potential for making a positive impact. By shedding light on the impact that the out-of-home sector is having on diets, this also enables us and the wider sector to consider what action may be required within the out-of-home sector to reduce obesity. This understanding will, in turn, influence the decision-making and priorities of government, industry, and other key stakeholders.

The out-of-home sector has rapidly expanded in the last 20 years with eating out going from an infrequent activity centred around special events to becoming an informal occasion within everyday life. It is estimated that in the UK 27% of adults and 19% of children consume foods outside of the home at least once a week. Existing evidence also suggests that meals offered in out-of-home settings often have excessive calorie content, likely significantly higher than meals consumed at home. While others have tried to explore the OOH sector, this has mostly relied upon data with significant underreporting of food consumed (e.g. National Diets and Nutrition Survey) or focussed on analysing menu items offered without knowledge of their sales. Without accurate evidence, we are unable to know how this is affecting diets and the solutions that could be pursued.

The focus of the project has been informed by extensive internal and external stakeholder engagement activities which have led us to shortlist several research questions. These revolve around investigating the practices and offerings in the out-of-home sector that are most likely to be drivers of high purchases of calories, the characteristics of the consumers of out-of-home food and the demonstrated behaviours that are most likely to be associated with high calorie purchases.

Nesta’s healthy life team will utilise a longitudinal dataset obtained by an international market research company capturing food and non-alcoholic drink purchases for a representative sample of around 5,000 individuals in Great Britain in 2021 alongside nutritional information for products collected either via barcodes or web scraped from restaurants’ websites. The latter source has been provided to Nesta by the University of Cambridge. The dataset we are building is generated by linking several data sources and enhanced by natural language processing methods and machine learning models.

We will draw on our data science expertise to link and enhance these data sources. The data currently lacks comprehensive nutritional info and consistent product volume records, particularly for smaller eateries. We will address this by using Natural Language Processing and machine learning models to predict calorie density and volume based on product names and other attributes. Recording product volumes is important as it will allow us to report on weighted sales in the out-of-home sector which is crucial to understand the relative contribution of the sector to diets. We will analyse the linked data employing statistical methods and more advanced unsupervised machine learning techniques, including network science to identify product groups forming meals, shedding light on the relative contribution of the out-of-home sector to diets. Additionally, we'll identify common purchasing patterns among users, crucial for targeted interventions within this sector.

The data analysis work is supported by a range of activities. We will conduct a comprehensive review of existing evidence to ensure our work is firmly rooted in the most current context. When research questions cannot be answered by evidence review or data analysis we will conduct interviews with experts in the field and potentially gather public opinion through polling to understand commonly held beliefs and perceptions about the out-of-home food and soft drinks sector. Throughout the project, we will actively engage with key stakeholders in the sector to seek consensus on the primary issues we are investigating.

In our final output we will also take stock on current and proposed policies and regulations and conclude by making suggestions regarding what factors should be prioritised by policy and industry for maximising impact on population dietary health.