Can your shopping trolley secrets help science?

• Over 30,000 people visited our mock 'shop' in Open City Lab as a part of our re-opening programme.

• Researchers share how shopping data can help health research, and how visitors are helping to shape their work.

• Listen to Children of the 90s talking about their experiences of being involved in this research.

It’s lunchtime and you’re in a local supermarket trying to choose what to have for lunch that day – what do you pick? If you picked a meal deal (the classic combination of a main, drink and snack), your choice could be useful to science.

But how?

Researchers like Dr Anya Skatova and her team at the Digital Footprints Lab in the University of Bristol have been looking into people’s shopping to see what it could tell us about their health. 

For example, they’ve found that lunchtime meal deals are a surprisingly useful tool. When everything costs the same, it is easier to see what people are prioritising besides price. The team looked at how people’s calorie intake varied over time. They found that people who buy lunch earlier in the day have less calorific meals on average compared to people buying later in the day. The same applies to the time of year – as the colder months of November and December roll around people tend to buy into the ‘treat yourself’ mentality. In January the calories tail off again, as New Year’s resolutions to be healthier come into effect. The team also found that the more that someone’s calories varied, the more calories they tended to consume overall. Such insights into calorie intake could help research into how and why people change weight over time.

The researchers collect people’s loyalty card data (with their permission) to look at more than just meal deals. But even though the data is anonymised, our shopping can say a lot about us and not everyone is comfortable with that. The Digital Footprints team want to know how people feel about sharing their shopping data for health research.

So, we teamed up to create ‘Shopping Trolley Secrets’ as a part of We The Curious’ reopening programme. It's just over one year since we re-opened our doors with a mini ‘shop’ stocked with packaging donated by staff to give them a new lease of life, wooden toys, and toddler sized baskets. Visitors could ‘go shopping’ and ‘checkout’ their items to tell the researchers what they would be happy to share with them. From July 2024 until February 2025, we welcomed over 30,000 people to the Open City Lab to share their thoughts. 

Visitors wrote many, many postcards to the researchers with lots of suggestions for future research directions. The cost of living crisis was a popular topic, as were ultra-processed foods. ‘Free from’ foods were at the intersection of these, with some people concerned about both the price and level of processing that can be required for these items. 

While most people were supportive of sharing their data for health research, there were some common concerns. Among them was whether companies could use the extra information about their health to sell them more things, for example, could companies predict when someone was on their period and try to promote chocolate or period pads? 

Dr Romana Burgess who is part of the Digital Footprints Lab acknowledges these concerns; “Companies already look at what people buy for marketing purposes while our goal as researchers is on health and doing some good with that data.” Visitors also suggested new areas for research, for example, how specific health conditions and shopping habits intersect. To answer these kinds of questions, and find new connections between purchases and people’s health, linking shopping data to health records such as prescriptions or blood tests could be key.  

Some research in this area is already being done by Digital Footprints Lab with the Children of the 90s study. We sat down and talked to some of the people involved, including participants who shared their shopping data. They reflected on studies like this using their data and what researchers might see from their shopping. 

So, what’s next?

It's through insights from all of you that helps the researchers decide what to do next. Romana and others from Digital Footprints Lab have already been thinking about how to explore links between Free From food and health after reading your postcards. There are many more thoughts (over 500 postcards to read!) meaning it will take a while for the researchers to absorb everything and then complete the research. But we’re really excited to catch up with them and share what they’ve been up to.