Case Study: The proof is in the basket: How smart legislation can make healthy the easy choice

The UK’s food system is under pressure to deliver healthier, more sustainable diets - and fast. With obesity rates rising and public health costs soaring, the government’s HFSS (high fat, salt, sugar) placement legislation was a bold attempt to shift shopping habits. But does it actually work? 

For the first time, independent researchers at the University of Leeds answered that question. Their findings are a wake-up call for the whole industry: change the environment, and behaviour follows. 

What the research did 

The Nutrition and Lifestyle Analytics team at Leeds worked with sales and product data from Asda, Morrisons, Sainsbury’s and Tesco, analysing millions of transactions before and after the legislation came into force in England in October 2022. 

The team also surveyed almost 2,000 shoppers and interviewed retailers, enforcement officers and the British Retail Consortium. They mapped results against the Priority Places for Food Index, a tool that identifies neighbourhoods where access to affordable, healthy food is most urgent. 

This wasn’t theory. It was a rigorous, real-world look at how regulation reshapes what goes in our baskets.  

What they found 

• Two million fewer HFSS items were sold every day. 
  Before legislation, 20 out of 100 supermarket items sold were HFSS; afterwards, it dropped to 19. A small shift, but at scale, hugely significant. 

• It was a step change, not a slow drift. 
  The decline happened right after the legislation, not gradually, showing the law, not inflation, caused the effect. 

• The impact was equitable. 
  Results were consistent across richer and poorer neighbourhoods, countering fears that vulnerable groups would be left behind. 

• Retailers adapted fast. 
  Some replaced HFSS promotions with healthier products, while others filled gaps with alcohol, baby food or digital ads. Reformulation accelerated too, as brands raced to bring products under the threshold. 

• Shoppers supported it. 
  Most saw the legislation as positive, even if 73% claimed it wouldn’t affect them personally. In reality, their behaviour shifted regardless. 

So, what does this mean for the food industry? 

The message is clear: design the food environment and you shape demand. Shoppers may not notice changes to shelf layouts or reformulation, but their baskets reflect them. And when healthier products are more visible and less healthy options less convenient, healthier choices become the default. 

The research also highlighted that legislation with loopholes is less effective. Without guidance on what should replace HFSS products in prime spots, retailers filled space in wildly different ways. Stronger rules could accelerate change and create a level playing field.  

Why food businesses should care 

This research is more than proof of policy impact; it’s a roadmap for industry action. Food businesses don’t need to wait for regulation. The opportunity is to: 

• Design for defaults: Make healthier options prominent, convenient and irresistible. 

• Balance price with purpose: Reformulate without compromising taste or cost competitiveness. 

• Build trust: Show the data, tell authentic stories and demonstrate tangible outcomes. 

• Act ahead of policy: Use this evidence to shape your own standards and guardrails now. 

The future of food is choice by design 

The Leeds University research proves that when you change the rules of the game, consumer behaviour follows. For businesses, it’s a powerful reminder: don’t wait for demand - create it. 

Healthier, sustainable diets won’t scale on consumer intent alone. They will scale when the industry makes them the easy, affordable and the default. 

Explore the outputs of the research in more detail here: https://www.sciencedirect.com/science/article/pii/S0306919225001460