Most of us have done it - picked up food that we have dropped on the floor and eaten it, while telling ourselves that it doesn't matter because of the ‘five-second rule'. Now a new study suggests that such a rule may actually exist.

According to UK scientists, while many people follow this ‘rule', it is largely considered to be an urban myth, therefore they decided to investigate whether there was any scientific basis to it.

They monitored the transfer of the bacteria E.coli and Staphylococcus aureus to four types of food - sticky sweets, biscuits, toast and pasta - which had been dropped onto the floor for between three and 30 seconds. A range of different floors were considered, including laminate, tiles and carpet.

The study found that time is a major factor when it comes to the transfer of bacteria from the surface of a floor to a piece of food. Food picked up after only a few seconds is less likely to contain bacteria than food left on the floor for longer.

The study also found that the type of floor was important. Overall, bacteria were least likely to transfer from carpet, and most likely to transfer from tiles or laminate floors, to moist foods which had made contact for more than five seconds.

"Consuming food dropped on the floor still carries an infection risk as it very much depends on which bacteria are present on the floor at the time, however the findings of this study will bring some light relief to those who have been employing the five-second rule for years, despite a general consensus that it is purely a myth.

"We have found evidence that transfer from indoor flooring surfaces is incredibly poor, with carpet actually posing the lowest risk of bacterial transfer onto dropped food," noted lead scientist, Prof Anthony Hilton, of Aston University in Birmingham.

Meanwhile a survey of people by the scientists revealed that ‘a large majority of people are happy to consume dropped food'.

"Women are the most likely to do so. But they are also more likely to follow the five-second rule, which our research has shown to be much more than an old wives tail," Prof Hilton added.