Australia has a dirty little secret and it could be making us sick.

According to the Food Safety Information Council, one in five Australians don't wash their hands after going to the toilet.

In the video above: Sunrise GP Dr Ginni Mansberg on the adverse effects of not washing hands

"The faecal-oral route is the number one cause of spreading diseases," Dr Ginni Mansberg told Weekend Sunrise.

The data reveals that men are the worst offenders, while two in five people don't always wash our hands before handling food.

"Apparently 76 per cent of blokes do wash their hands after the bathroom...86 per cent of women wash their hands," Dr Ginni said.

More from 7NEWS.com.au:

Younger people were also less likely than older age groups to wash their hands after using the toilet.

"Good handwashing, using running water, soap and drying hands thoroughly is a basic public health message that people seem to be forgetting," says the Food Safety Information Council's Lydia Buchtmann.

"This behaviour could be contributing to the estimated 4.1 million cases of food poisoning each year, not to mention spreading viral infections such as cold, influenza and norovirus," Ms Buchtmann said.

The Food Safety Information Council advises people wash and dry hands:

before handling, preparing and eating food

after touching raw meat, fish, shell eggs or poultry

after using the toilet and changing nappies

after blowing your nose

after touching a pet

after gardening

The best technique to avoid spreading disease is to:

Wet hands and rub together well to build up a good lather with soap for at least 20 seconds, washing between fingers and under nails.

Rinse well under running water to remove the bugs.

Dry hands thoroughly on a clean towel for at least 20 seconds. Touching surfaces with moist hands encourages bugs to spread from the surface to hands

If no running water is available, use an alcohol gel.

More information is available here.