The average family with children throws away £680 of food a year, according to research.
The sum, which equals £13 a week, makes a total of £12 billion across the nation.
The study found that the average household spends £68 a week on food but that 91% of households with children admit to throwing some of that food away.
Researchers said that the value of wasted food was heavily underestimated by families. In a poll of 2,116 adults, average families estimated wasting more than £270 a year (£5.20 a week) on discarded food.
The survey carried out by Birds Eye with research by Wrap (Waste & Resources Action Programme) found that the figure was actually £680.
Vegetables topped the list of the most commonly wasted food group, followed by bread and fruit, and 40% of those polled felt guilty for wasting food.
The main reason cited for wasting food was buying too much (37%), with 22% doing so because of supermarket offers including buy one get one free deals or similar. Lack of meal planning prior to shopping was another issue, with one in three people admitting to not planning.
Families with children at home proved more savvy, with 37% saying they planned more than before the recession. The news comes as a report by the Fabian Society and Birds Eye, looking at consumer attitudes to food waste, is discussed in Parliament.
Waste Minister Lord Taylor of Holbeach said: "Wasting perfectly good food is bad for household budgets and bad for the environment, which is why we are taking action to help people cut down on what they throw away.
"Through Wrap's Love Food Hate Waste campaign we are helping households to waste less and save money, while our new guidance on food date labelling has cleared up confusion about when food is safe to eat."