• Scalable changes to Starbucks espresso-based drinks ordered on app led to a measurable shift towards healthier choices
• Changing the default selections and ordering of options in the app led to more people buying the healthier mochas, rising from 17% to 55%, and leading to a 14.5 kcal (4.1%) decrease in calories and a 3.3g (7.9%) reduction in sugar per mocha
• If similarly effective interventions were designed across the coffee sector it would lead to fewer people living with obesity and excess weight, potentially reducing those costs to society by around £100 million a year

London, UK - A trial on the Starbucks app has demonstrated that subtle, customer-friendly changes are effective at reducing calories in people’s beverage orders and boosting orders of healthier options.

The three-month trial by Starbucks and innovation foundation Nesta, from May to August 2024, changed default settings and positioning of products in the UK Starbucks app. The default coffee bean for core espresso-based drinks was set to ‘blonde roast’, which has a shorter roast time, resulting in a lighter roast with a naturally sweeter flavour. This allowed drinks containing syrups and sauces to be made with reduced amounts of these ingredients. Customers also had the option to switch back to the signature espresso roast.

The trial was successful at reducing the number of syrups and sauces used in a range of drinks by switching to the naturally sweeter blonde roast coffee beans as a default. In particular, customer selection of the default blonde roast coffee bean surged from 17% to 55% for mochas, suggesting customers embraced the healthier option. For mocha orders specifically, the combined changes led to a 14.5 kcal (4.1%) decrease in calories and a 3.3g (7.9%) reduction in sugar per mocha, the most significant change observed. Across espresso-based beverages as a whole the blonde roast default saw a statistically significant 2.1 kcal (1.4%) decrease in average calories per drink.

Across all products, the changes made in the trial led to a statistically significant 1.1 kcal (0.6%) drop in calories and a 0.5g (2.1%) reduction in sugar per beverage overall among app customers.

The interventions did not appear to affect sales. Daily purchases increased across both app and in-store channels during the trial, suggesting the changes were commercially viable.

Nesta will now look at whether the trial can be replicated and scaled. If the 4.1% reduction in calories purchases seen in mochas could be scaled across all coffee sold in the UK, this could lead to around £100 million in social value per year through reduced rates of obesity and excess weight, including boosted productivity and reduced costs to the NHS.

Dr John Barber, deputy director of healthy life at Nesta, said: “This trial provides compelling, real-world evidence that subtle changes to improve people’s health can be acceptable to customers and viable for business.

“Reductions to the calories and sugar in someone’s Starbucks mocha order may seem modest on an individual basis, but if the wider coffee sector were to adopt similarly simple, scalable changes, our analysis shows there is potential to unlock significant benefits in improved health. By using defaults on the app, this is also done in a way that doesn’t impact customer agency to buy the drink they want. We hope that drinks retailers and other takeaway businesses will see that using the right data and a combination of innovation to recipes and tweaks to how food and drink options are presented can make it easier for people to make healthier choices. Ultimately, we want this approach to contribute to reducing the UK’s too-high obesity rate.”

According to the British Coffee Association, 80% of people who visit coffee shops do so at least once a week and 16% visit daily.

Nesta and Starbucks formed a collaborative partnership in March 2024, as part of Nesta’s mission to halve the prevalence of obesity in the UK by 2030, including through new, innovative solutions to drive healthier choices for consumers. Nesta’s other ongoing partnerships include one with Deliveroo and restaurant chain Maki & Ramen.

Notes to editors

1. The trial analysed beverages purchased by Starbucks customers in the UK between 2 May 2024 and 7 August 2024. The blonde roast intervention was applied to core espresso beverages ordered through the Starbucks app; repositioning of healthier drinks, syrups and milk options was applied across all drinks on the menu.
2. Nesta has estimated that a 4% reduction in calories consumed scaled up for the whole coffee sector in the UK could lead to around £100 million in social value per year, through reducing obesity and excess weight at a population level by 0.15%. This is based on calculations on the financial impact of reducing obesity and excess weight in the 2023 report by Frontier Economics, commissioned by the Tony Blair Institute, “The rising cost of obesity in the UK”.
3. The Starbucks Blonde Roast coffee beans are a unique tailor-made blend by Starbucks using 100% arabica.
4. For more information on the trial or to speak to one of the experts involved, please contact Kieran Lowe, Media Manager, on 020 7438 2576 or [email protected]. Spokespeople are available for broadcast interviews.
5. To contact Starbucks about the trial, please email [email protected].

About Nesta

Nesta is a research and innovation foundation that designs, tests and scales solutions for the biggest challenges of our time.

Driven by a vision to improve the lives of millions of people, our focus up to 2030 is on three missions: breaking the link between family background and life chances, halving obesity and cutting household carbon emissions.

We work with partners to develop high-potential solutions and test them as they evolve, drawing on expertise in qualitative and quantitative research, data science, behavioural science and design.

Once confident in the effectiveness of a solution, we take it to scale. We create national policy proposals, develop consumer-facing products and services, build and spin out commercial ventures and harness the power of the arts.

We work with two specialised units: BIT applies a deep understanding of human behaviour to help clients achieve their goals. Challenge Works designs and runs challenge prizes to spark innovation in science, technology and society. Find out more at nesta.org.uk