Market researcher Kantar said the four week period was the busiest in store for grocers in more than a year, and the number of trips made in April increased by 4% compared to March.
"With much of the over-65 community now vaccinated, older shoppers accounted for nearly half of the increased footfall," said Fraser McKevitt, head of retail and consumer insight at Kantar.
In contrast, the number of people shopping online fell for the second consecutive month. Digital orders accounted for 13.9% of grocery spend, down from a peak of 15.4% in February.
Kantar said the return to sales growth in the latest four-week period also reflected what was happening in April 2020.
After the initial rush to stock up before Britain's first lockdown, this time last year was comparatively quiet. Shoppers chose to buy locally and minimize their trips to stores where possible, which is reflected in strong growth a year later.
"While the market may fluctuate between growth and decline in the months ahead, depending on the year-on-year comparison being made, the fact that trip numbers are up and basket sizes down suggests that habits are slowly returning to normal," said McKevitt.
Over the 12 weeks to April 18, Asda, with sales growth of 8.0%, was the fastest growing of Britain's big four grocers for the first time in nearly two and a half years.
Market leader Tesco's sales rose 6.4%, with Sainsbury's up 6.0% and Morrisons up 7.2%.
Kantar said grocery prices fell 0.3% over the 12 week period.
It said prices are rising fastest in markets such as chilled fruit juices and drinks, canned colas, and chocolate, while falling in bacon, vegetables, and toilet tissue.
(Reporting by James Davey, Editing by Rosalba O'Brien)
