It takes four to 12 seconds to decide what to buy at the supermarket shelf.

Shoppers don’t have the time, knowledge or bandwidth to weigh up their carbon footprints. They are thinking about budget, wellbeing, convenience and quality.

That insight sits at the heart of CarbonTrac – an AI-powered tool built by Yasmine Abdu when she was an chemical engineering student, to help people make better food choices that are also better for the planet.

Food systems account for around a third of global greenhouse gas emissions, so what people buy and eat matters.

“The data supports the fact that people want to make better choices,” she said.

To test that, Yasmine and a team of volunteers stood outside supermarkets and interviewed more than 1,000 shoppers across the UK.

Her research confirmed while 80% of Gen Z and millennials say they want to make more sustainable choices, only 12% actually do. Good intentions were there but something was getting in the way.

“We have got a cost of living crisis. Nobody is going to think, ‘I want to pick this for the planet first .’ You are going to think about your wallet. In those four to 12 seconds, it is all about health, convenience and quality,” Yasmine said. “If you put carbon in the mix, it doesn’t stand a chance, because the cognitive load is already too much.”

Around 95% of people in Britain aged 16-75 have at least one supermarket loyalty card. A personal health issue prompted Yasmine to look at that data differently, and she realised this could be the way to turn good intentions about the environment into better actions by appealing to personal interests.

“You can’t get to sustainability without getting to nutrition. I had a folate deficiency. Supermarkets already know exactly what I’m buying every week, why couldn’t they tell me?” she said.

CarbonTrac is designed to integrate directly into supermarket loyalty apps, working in the background without adding extra steps. It analyses a shopper’s basket and personal profile, flags potential nutritional gaps and suggests practical swaps that are cheaper, healthier and lower in carbon - all surfaced through a simple, easy-to-understand dashboard.

Yasmine believes this approach will benefit supermarkets as well as shoppers. If customers are getting useful prompts and realistic swaps, supermarkets can increase basket value and loyalty at the same time as helping people eat better and cut carbon.

In 2025, CarbonTrac won the UK Green Startup of the Year and has opened doors for Yasmine to contribute to wider conversations on food systems, health and technology, including work informing public health innovation at WHO/Europe and the future of food systems at the UN FAO World Food Forum.

“It’s always been my dream to work with the UN,” she said. “Now I have worked with six different UN entities. It is a massive responsibility but to change the system, I believe you have to be in the system.”

Yasmine has been backed by an £8,000 Starting Up Millennium Awards Trust Award from UnLtd: “I was looking for support that understood social impact,” she said. “You need an anchor like UnLtd, somewhere that holds you accountable to keep going.

“My mentor Amjid has been fantastic. He checks in on how things are progressing, asks how I’m managing, and has already offered to make some really helpful introductions. “Having that extra direction is so important, particularly when you’re young and don’t have experience in every area.”

This willingness to move, test, adapt and keep going is one of the things that gives social entrepreneurs their power. Now, with support from UnLtd, Yasmine is focused on her biggest challenge yet: persuading supermarkets to pilot her technology.

“Industry will never move as fast as we can as startups,” Yasmine said. “We can change direction tomorrow. We can adapt to any change in AI tomorrow. It is up to the social entrepreneurs to reshape the system.”

Described as ‘infrastructure that changes behaviour at scale’, there is huge ambition for CarbonTrac:

“I think it would only really hit me when we can quantify and say we helped detect cholesterol levels before they became an issue, highlighted 20,000 deficiencies, or reduced the carbon footprint at scale,” said Yasmine.