Prime minister Gordon Brown has urged supermarkets to scrap 'three for two' deals on food that encourage shoppers to buy more than they need.
He also called on shoppers to stop wasting food after research showed that Brits were binning 4m tonnes of food each year.
Speaking as he arrived in Japan for the G8 summit, Brown said that "unnecessary" purchases were contributing to the rising cost of living, adding £420 to a family's annual food bill.
The food policy study also found the average UK household throws away £8-worth of leftovers a week, yet spends 9% of its income on food. It also showed a significant gap between the poorest 10th of the population, who spend 15%, and the wealthiest, who pay out 7%.