Young people are the least likely to recycle food waste, a campaign group has said.
Research conducted by Recycle for Wales shows 43% of 18-24-year-olds and 34% of 25-34-year-olds put leftover food in the rubbish bin.
In contrast, 95% of over-65s claim to recycle their food waste.
The group, which is funded by the Welsh Government, said the most common reason for not recycling food was that it was "too messy or smelly".
Around 350,000 tonnes of food waste from Wales ends up in landfill annually.
The research also reveals that single people in Wales are the most likely to put food in the waste bin - with 18% of single households admitting they rarely recycle food, compared to 7% of couples.
Angela Spiteri, from Recycle for Wales, said: "People who are put off food recycling because they think it may smell don't realise that recycling it rather than putting it in the bin can create less smells.
"Food waste gets collected weekly and in-home food caddies are recommended to be emptied more often than regular bins."