An estimated 12 million British workers who do not eat their five-a-day are reducing their ability to work effectively, according to vielife.
Respondents with poor nutrition scores reported 50% more sickness absence than those with good nutrition scores. It is costing the average UK organisation an extra 576 days for every 1000 people employed.
Those with low scores were 15% less productive equating to 2.8 hours each week difference and 16 days of lost productive time each year per employee.
Tony Massey, chief medical officer at vielife, said: "UK firms cannot afford to ignore the impact of bad nutrition which is not only rivalling but also contributing to rises in other big personal and work life issues like sleep and stress."
One in ten people said they eat recommended six portions of fibre each day, while less than one in five people managed to eat their five portions of fruit and vegetables.
High stress levels were experienced in 38% of people with poor nutrition compared to 19% of people with good nutrition.
And those with good nutrition had 6% higher job satisfaction and 15% higher mood scores.
The data was recorded for 40,000 working UK adults from vielife online health and wellbeing assessments. It showed 36% had poor nutrition.
The nutrition score allocated indicated the overall quality of the individual's dietary habits. It was part of a wider ‘wellbeing score' used to help people identify and improve health issues.
