How calorie labels on food apps affect choices
Obesity is a serious health challenge. In the UK, 63% of adults are overweight or live with obesity. Out of home (OOH) meals – food consumed from restaurants, cafes and takeaways – can be a great treat but tend to contain many more calories than meals cooked at home. Food delivery apps have made it incredibly easy for people to access this calorific food.
One approach that is being considered to help people make healthier choices when eating out is to introduce calorie labels for out of home meals. The Scottish Government and the Welsh Government are consulting on proposals to introduce calorie labelling at the ‘point of choice’, including on menus and delivery apps. Regulations to make calorie labelling mandatory in the out of home sector came into force in England in April 2022.
Testing the effectiveness of calorie labelling
To understand the potential value, acceptability and risks of calorie labelling in food delivery apps, Nesta conducted two complementary studies.
The first, in partnership with the Behavioural Insights Team, was a randomised controlled trial to evaluate the effect of calorie labels on the number of excess calories purchased from delivery apps. A total of 8,780 adult participants were asked to do a simulated food order on one of eight versions of a simulated food delivery app: the first app version did not show any calorie information, while the other versions featured one of seven calorie label designs.
For the second study, we asked a diverse group of 20 food delivery app users from the UK to interact with different versions of our simulated takeaway app, each featuring a different calorie label design. As participants were using the app, we asked them to narrate their experience out loud and highlight what was driving their choices.
The main findings and insights from both studies are combined in this report. However, the full, detailed results of each study are available separately.
Randomised control trial using a simulated takeaway app
In the randomised controlled trial, we found the introduction of calorie labels to be effective at reducing the number of excess calories purchased.
- All seven calorie labelling options resulted in fewer calories being purchased compared to no calorie labels, five at statistically significant levels.
- Total calories purchased reduced the most when participants had the option to hide or show the calorie label.
- Participants in this study overwhelmingly supported the idea of including calorie labels on food delivery apps. Between 71 and 76% of people actively supported the introduction of calorie labels. Not introducing a calorie label was the least popular option with only 28% of people supporting the idea.
- Adding a summary of the total calories purchased in the shopping basket before checkout led to a greater reduction in calories purchased compared to other labelling formats.
- The position and prominence of calorie information also contributed to the total number of calories purchased on the simulated app. Of the calorie display options, labels to the immediate right of the food items and in a different font from other text resulted in the biggest reduction in total calories purchased.
Exploring users’ views on calorie labels
Users in this study identified specific features of calorie labelling and concerns that governments, industry and other public health organisations should consider when implementing calorie labels in OOH environments.
Among the positive views, users felt calorie labelling:
- empowered them to act on their existing personal intentions and goals
- supported their right to know more about the food they purchase
- helped them build nutritional knowledge over time
- were important for people on a calorie-restricted diet for medical or personal reasons; and
- informed decisions on the calorie intake in subsequent meals (not just the meals for which they were exposed to calorie labels).
Users also identified potential drawbacks to calorie labelling, including:
- interpreting ‘low-calorie’ labels as indicating small portion sizes, poor taste, and low anticipated satisfaction
- that calorie labels would invoke feelings of guilt for some people, including triggering users with disordered eating.
Users specifically identified the option to switch calorie labelling on or off as a helpful feature that could protect vulnerable people and give people agency over labelling depending on factors such as mood or occasion.
Users also suggested supplementing calorie labels with other health-related information, for example wider nutritional information, to help signal that calorie information is intended as a health-promoting initiative rather than a cosmetic one.
The inclusion of a summary of total calories ordered in the checkout basket was considered by some participants to be helpful. However, some participants thought that depending on how the summary calorie content of a basket was displayed, this feature could exacerbate the risks of triggering negative feelings.
What does this mean?
Nesta’s goal is to halve the prevalence of obesity across the UK. To reach that goal we need to help people reduce the number of excess calories they consume. We recently estimated that halving obesity prevalence could be achieved by a reduction of 216 kcal daily on average, for people living with obesity.
When it comes to eating at home, our analysis of household purchases suggests that reformulating some food categories – using new ingredients, changing recipes or adapting manufacturing processes to reduce their calorie density – would be one way of helping people to consume fewer excess calories.
From these studies, calorie labelling appears to be another effective way of doing this on takeaway delivery apps. However, consideration must be given to how the design and position of labelling and features – such as the choice to hide or show labelling and the inclusion of basket totals – affects people’s experience of using these platforms. We recommend further studies evaluating the impact of calorie labels in a real-world context.
Read the full reports for more detailed analysis and specific policy implications and recommendations.