The boss of Sainsbury’s has warned shoppers are "watching every penny and every pound" as food prices continue to rise.
Chief executive Simon Roberts said life is “tough for millions of households” who are also battling against sky-high energy bills.
The supermarket revealed its pre-tax profits fell by 8% to £340million after being hit by higher costs and higher wages.
Sales rose by 4.4% to £16.4billion in the six months ending in September.
Mr Roberts said: "We know [customers] are relying on us to keep food prices as low as we can.
“We will have invested more than £500million by March 2023 in keeping prices lower by cutting our costs at a faster rate than our competitors, meaning we have more firepower to battle inflation.
“Over the past year and a half we have consistently passed on less price inflation than our competitors and I am confident we have never been better value.”
Retailers are being hit by higher costs for ingredients, energy and transport, with the price being passed on to consumers.
The war in Ukraine has also disrupted supplies of goods such as grain, oil and fertiliser from the region.
It comes as overall inflation - the rate at which UK prices rise - surged to 10.1% in September and is now at a 40-year high.
When inflation is high, it means the cost of living has increased and you’re getting less for your money than you did before.
Food was one of the biggest contributors behind the latest rise - along with rising energy costs - with prices up 14.5% in the 12 months to September.
The Bank of England has been raising interest rates to try and cool inflation, with the base rate now sitting at 2.25%.
Analysts suggest interest rates could be hiked to 3% this afternoon, in what would be a 33-year high.
Which? head of food policy Sue Davies said that soaring food prices "are a real concern" for shoppers.
"Millions of consumers are already skipping meals or struggling to put healthy meals on the table due to the cost-of-living crisis," she added.
"It is vital that households get the support they need from the government and businesses."
