Obesity has now overtaken smoking as the biggest cause of preventable death in England and Scotland, according to recent research. Nesta and the Behavioural Insights Team (BIT) set out below why we think making changes to the way we shop for food online could help us to live healthier lives. We also suggest actions that retailers, researchers and policy makers can take to help people make healthier online food choices.

In April 2020, one month after the UK entered its first national lockdown, online grocery sales doubled and takeaway deliveries saw a 21% rise compared with the previous year. While online grocery sales have fallen slightly from their lockdown peak, they remain high: over a four week period in July and August 2021, 20% of UK households in the UK ordered online deliveries from supermarkets. It’s not just supermarkets that offer online grocery shopping. Since the pandemic, several rapid grocery delivery services such as Weezy, Gorillas and Getir, provide cheap groceries delivered in under 20 minutes in several large cities.

Though the total amount of food purchased through online takeaways platforms is expected to be smaller than that purchased from online supermarkets, they are likely to be an important source of calories in people's diets. A 2021 survey found that 67% of adults had used JustEat, the most popular delivery platform, in the previous year. Research shows that while there are exceptions, the majority of takeaway meals exceed dietary energy, fat, sugar and salt recommendations and that exposure to takeaways is associated with higher obesity prevalence. Furthermore, the higher density of takeaways in areas of greater deprivation suggests that consumption of takeaway fast-food may contribute to health inequalities.

Retailers can have a positive impact on consumers' food choices, helping to reduce the prevalence of obesity. Research suggests that shopping online may reduce impulse purchases. In one US study, consumers spent less on sweets and desserts when shopping online, compared to shopping in-store. This may be due to reduced exposure to till point or end of aisle promotions, or because online food sites present users with a shopping list based on previous purchases, limiting the opportunity for browsing and impulse purchases. Other researchers have suggested that online shopping might be more conducive to healthy shopping by allowing customers to filter by nutrition-related attributes, such as those low in salt or sugar.

Evidence that people buy fewer unhealthy products online is based on observational evidence rather than randomised controlled trials. It is therefore not clear if it was the online shopping experience itself that led to healthier food choices. For example, it may be that people who are more likely to shop online, who tend to be younger and wealthier, are more likely to make healthier food choices regardless of where they shop.

Online shopping can be more convenient for people with physical access issues, but evidence suggests that the young and wealthy are currently the biggest users. One survey found that wealthy UK consumers are ten times more likely to order groceries online compared to lower-income groups and data suggests that people aged 25 - 54 are more than twice as likely to shop online than those over 55. This suggests that, though online food services have the potential to help more people access healthy food, steps need to be taken to make sure everyone can benefit from them. Not doing so risks exacerbating existing disparities in obesity prevalence; adults in the most deprived areas of the UK are in excess of 50% more likely to be obese than those in the least affluent areas.

One potential way to help lower-income families access online shopping services is to open up current welfare assistance schemes to online shopping. The Supplemental Nutrition Assistance Program (SNAP), a US based initiative that provides those with low incomes with monthly food benefits, allows participants to buy groceries online — uptake varied greatly between participating states. In an average month in 2020, 2% of SNAP recipients in Vermont and up to 17% in Kentucky used SNAP online. Similar schemes in the UK, like the Government's' Healthy Start voucher scheme, cannot be used online.

There are many changes that online retailers, including large supermarkets and smaller retailers, takeaways and other food delivery outlets, could make to encourage customers to make healthier choices. These changes focus on removing cues that push people towards purchasing unhealthy foods and on adding nudges towards healthier options.

Access to retailers’ data and robust evaluation can help to increase our understanding of the impact of online interventions that aim to encourage healthier eating. Nesta is keen to work in collaboration with retailers to analyse their data and test the impact of interventions in real-life shopping contexts, rather than relying on experiments using simulated shopping platforms. Research would also be advanced by the open sharing of data by retailers so that researchers could explore:

• The nature and impact of product promotions and positioning on the homepage, in search results, at checkout and in promotional emails
• The effectiveness of online nudges to encourage healthy eating. This could range from explicit promotions and suggested swaps to testing the impact of priming online shoppers with different imagery on web landing pages
• The feasibility and impact of offering a feature that automatically creates healthy shopping baskets for people
• The effectiveness of different default search filters to support healthy eating
• The impact of promotions and nudges on different types of shopper

Online food environments present opportunities to help improve the nation’s health, which government could play a leading role in shaping. For example, developing evidence-based guidelines for online food retailers on best-practice, for example in the ordering of search results. Policymakers might also explore the feasibility of implementing consistent, simple and accessible ratings for retailers, just as the Food Standards Agency does with hygiene ratings, showing which retailers promote healthy products. In addition to tipping the balance of competitive pressure in favour of healthier providers, this may serve to incentivise retailers to make adjustments to meet the threshold of the better ratings.

Online food delivery platforms, whether for groceries or takeaways, represent just some of the complex web of environmental and personal factors that come together to drive our food choices. However, the rapid rise in their popularity, coupled with the relative ease with which potentially impactful changes to the way food choices are presented can be made and tested, provides an opportunity for retailers, researchers and policy makers to make it easier for consumers to make healthier food choices.

We are interested in working with policymakers and retailers of all sizes to explore ways of making online services better for customers' health and for business. If you have any thoughts or questions, or would like to work with us, please get in touch with Jonathan Bone.