Wairarapa Road Safety Council manager Dave Ryan said restaurant drive-throughs may be part of the problem, as they encouraged people to keep driving as they ate.
He had heard anecdotal evidence of incidents involving eating, such as hot pies falling on laps, but said they weren't specifically defined in their road-crash statistics.
"It's probably not the best thing to do," he said.
Wairarapa Police Senior Sergeant Carolyn Watson said while it wasn't illegal to eat while driving, it could still lead to charges.
"If you're distracted by eating and you cause a crash you could be facing careless driving charges," she said.
A study by researchers at England's University of Leeds found drivers' reaction times were slowed by 44 per cent while eating, and by 22 per cent while drinking.
A 2011 AA Insurance Drivers Index survey also found eating while driving was among the 10 most common distractions for drivers.
AA Insurance head of operations Martin Fox said analysis of New Zealand claims showed most motor accidents were caused by driver distraction.
"Whether it's a cup of coffee, or unwrapping a sandwich or a pie ... anything that means you have to take your eyes off the road is very dangerous," Mr Fox said. "We do see some really upsetting accidents, where drivers have unfortunately been distracted and not been able to slow down and a collision has occurred, and those are some very bad accidents."
The top distractions were texting, talking on the phone, having children in the car, and using a GPS, changing the radio station, talking on a hands-free mobile, other passengers, eating while driving, people outside the vehicle and billboards or advertising.
