The latest research from Which? has unveiled the supermarket items experiencing the fastest price surges. Fish prices saw the most significant increase at 9.7% year-on-year in May, followed by energy drinks at a 5.9% rise. On the contrary, butters, spreads, and chocolate were the only categories to witness a decline, with a decrease in inflation by 0.8%.
Overall, Which? reported a cooling trend in food price hikes, with annual inflation for supermarket food and drink dropping to 3.1% in the three months leading up to May 2026, down from 4.1% in February. This marks a notable decrease from the peak of 17% recorded in the three months until April 2023. Additionally, food inflation fell to 2.4% on a monthly basis in May.
Waitrose stood out with the highest inflation levels, showing a 3.8% annual price increase in May, while Aldi had the lowest at 0.8%. A Waitrose spokesperson mentioned investing over £20 million in reducing prices across their product range to maintain quality and high welfare standards.
Which? highlighted that supermarkets lack access to its full list of 25,000 items included in the inflation tracker. Own-label budget groceries faced a 4% range-based inflation, while branded groceries experienced a milder increase at 2.2%.
Separate research from Worldpanel by Numerator revealed a decrease in UK grocery inflation to 3.1% for the four weeks ending May 17, 2026, down from 3.8% in April. Data from the Office for National Statistics (ONS) indicated a 3% rise in food and non-alcoholic beverage prices in the 12 months leading up to April 2026, compared to 3.7% in the 12 months until March.
Reena Sewraz, Which? Retail Editor, emphasized that although food price inflation seems to be easing, consumers are still feeling the impact of years of climbing grocery costs. With expectations of rising inflation in the future, shoppers are keen on finding ways to reduce their weekly shopping expenses.
Andrew Opie, Director of Food & Sustainability at the British Retail Consortium, acknowledged retailers’ efforts to offer value to customers amid challenges such as increased energy and commodity costs due to geopolitical tensions and government policies.
In conclusion, the data for May 2026 shows varying inflation rates among supermarkets, with Waitrose at 3.8% and Aldi at 0.8%. Furthermore, Aldi emerged as the most budget-friendly supermarket overall, highlighting the benefits of price comparison and shopping around for consumers.