One in three consumers does not know the difference between the "best before" and "use by" date labels on foods, according to new research by Safefood.
It also found that 30% of purchased food is thrown away, with bread (43%), fruit (15%) and dairy products (12%) being disposed of the most.
To reduce food waste, consumers are advised to treat "best before" dates as a guideline and "use by" dates as a deadline.
Safefood and the Environmental Protection Agency have joined forces for a Stop Food Waste programme as part of the European Week for Waste Reduction, which began on Saturday.
Its aim is to encourage consumers to check the dates on food labels.
A "use by" date indicates the length of time that a food will remain safe to eat if properly stored. Food should be eaten by this date at the latest.
A "best before" date is about food quality rather than safety.
Food may lose flavour and texture after the specified date, but it does not mean that it will be harmful.