One in five workers does not take a lunch break, according to research by pollster YouGov.
The survey, conducted for business services firm Croner, questioned 1,234 people.
It found that 19% of respondents do not take any time off in the middle of the day.
It follows a similar survey undertaken by the same team, which found that nearly one-quarter of British employees enjoy an alcoholic drink during their lunchbreak.
Gillian Dowling, employment technical consultant at Croner, said employers are required by the Working Time Regulations to ensure that workers take a rest break.
“We all know that working long hours affects our ability to cope with our day-to-day roles, and as such we are starting to see more people question their work-life balance and taking appropriate action.
However, what some employees are failing to realise is that not taking time out in the working day can, in the long-term, also affect their health and their ability to do the job,” she said
Under the regulations, workers who work more than six hours a day are entitled to a rest break of not less than 20 minutes, which must be uninterrupted and should be spent away from the work station.