What does supermarket loyalty card data reveal about food purchase behaviours?
Dr Michelle Morris, UAF LIDA
This week LIDA and CDRC researchers presented two posters at the 13th European Nutrition Conference in Dublin, showcasing some recent work with the large UK retailer: Sainsbury’s.
The first poster presents PhD results from Vicki Jenneson, a student in our Data Analytics and Society Centre for Doctoral training. Results reveal that households in Leeds purchase, on average, 3.5 portions of fruit and vegetables daily. This is higher in affluent and rural areas and with 22% of households purchasing more than 5 portions per day. Conversely in poor, urban areas 18% purchase less than 1 portion per day.
The UK recommendations are to consume 5 portions of fruit and vegetables per day per person. It may be that people get their fruit and veg at school or buy them at a work canteen. However, the transaction data offer a novel and objective measure of fruit and veg purchases.
The second piece of work, from CDRC Research Fellow Stephen Clark, reviews the UK dietary recommendations, the Eatwell Guide, compared with loyalty card purchases for Yorkshire and the Humber. As a proportion of the weight of all purchases, fruit and vegetable purchases are encouragingly close to the recommendations, with 31% purchased compared with 39% recommended. Surprisingly purchases of starchy products, such as bread and pasta, were below the recommended with 17% purchased compared to 37% recommended. Meat and plant based protein products were similar to recommendations and more than twice as many dairy products are purchased compared to recommended. Perhaps unsurprisingly, sweet and savoury snacks like chocolate and crisps exceed recommendations with 17% of purchases by weight on these food, compared to 3% recommended. For the full abstract visit here,or view the poster here.
We are excited to be collaborating with Sainsbury’s on this work and by the potential of these types of transaction data to understand the food purchasing behaviours of our population. We accept there are limitations to these data as they may not capture all food consumed and that individuals may buy from multiple retailers. However, compared to limitations of self-reported data such as recall bias, in addition to the burden of completing a food diary, limiting the scale of data collection, these novel data sources offer great potential in future research and policy making.
The work described here is in the early stages, full academic papers are forthcoming.