Motorists munch their way through nearly one billion portions of junk food a month, a new study shows, writes David Duffy.

Drivers now eat so much chocolate while at the wheel that if all the bars eaten were laid end to end they would go around the 119-mile M25 153 times.

More than half (53 per cent) of those questioned admitted to eating and drinking beverages while driving, said the study, from the Autoglass company.

The study showed:

*Favourite items consumed while on the move include chocolate, crisps, canned drinks and burgers

*Londoners are the top car slobs, with 66 per cent admitting eating and drinking while behind the wheel

*The least-guzzling area is East Anglia, where three in five motorists prefer not to eat or drink at all while driving * Men tend to consume more in cars than women but both go for chocolate in a big way

*Young drivers are more likely to snack-and-drive.

Bad eating habits pose a threat to road-users and long-term damage to the nation's health, said Autoglass spokesman Karen Tovey.