The June survey said that 79% of shoppers expect food and grocery prices to rise in the year ahead, with 14 % expecting significant rises. That figure is up from 8% in April.
The expectation of price rises follows slight increases in inflation already, together with warnings from the Bank of England of further inflationary pressure to come.
Despite this, the IGD said that shopper confidence remains “relatively stable”, with more people expecting to be better off than worse off in the next year.
Lower-income households have a higher proportion of people (21%) concerned about rising prices than higher-income households (11%).
Simon Wainwright, director of global insight at the IGD, said: “Whilst it remains quite strong, the last month shows us that shopper confidence is fragile due to the relative uncertainty, as we begin to move forward from the pandemic.
“Concerns surrounding inflation are to be expected, but it’s reassuring to see that the rise in Covid-19 cases and delayed lifting of restrictions has not significantly impacted confidence levels, perhaps indicating that the UK population is ready to move forward in a post-pandemic world.”
Wainwright added that the key focus for retailers now will be on retaining shopper spending levels.
He said: “Focusing on quality and meeting the needs of shoppers who are economising are both key priorities.”