More than three in five drivers admitted to eating at the wheel in the past year, a survey by road safety charity Brake and insurance company Direct Line showed.
Based on responses from 1000 drivers, the survey showed that in the past 12 months, 29% have opened and eaten food at the wheel while 33% have eaten food that was unwrapped and passed to them.
Some 5% have shaved, combed hair or applied make-up in free-flowing traffic, while 15% have carried out personal grooming while their vehicle was stationary.
Brake deputy chief executive Julie Townsend said: "Driving is the most complicated and risky thing most of us do on a regular basis, so it is vital we give it our full and undivided attention.
"We can't afford to treat our cars as an extension of our kitchen or bathroom.
"Eating at the wheel dramatically increases your chances of crashing and killing or seriously injuring someone."