British businesses are losing an average 23.5 days of productive time per employee as workers take time off sick and underperform in the office due to ill health, according to Britain's Healthiest Company (BHC).

This is equivalent to eachworker losing more than an entire working month of productive time a year, translating into £57 billion across the country.

The survey of more than 32,000 workers revealed that 36% have a chronic condition, such as heart disease or diabetes, which are strongly associated with their lifestyle. The survey also revealed that many employees mistakenly believe they are healthy. Nearly two-thirds (61%) have at least two health risk factors. And a third are suffering from three or more. Around 60% of those with three or more risk factors believe their health to be good or very good, which makes them less likely to change their behaviour. Risk factors occur when people register as outside the 'healthy' range for a lifestyle or clinical health factor, due to lack of exercise or poor diet, for instance.

Encouragingly, however, the data shows that workplace wellness programmes can support employees to improve their health. Average time lost per employee due to absenteeism and presenteeism at the top five ranked companies in the BHC list was over a week less than the average firm. As companies increase their investment in health promotion, the proportion of employees in good or excellent health grows, while the costs to productivity associated with absenteeism and presenteeism decrease. The 25% of companies with the largest health promotion budgets saw an 8% annual improvement in the proportion of employees in good or excellent health, and a 16% annual reduction on productivity loss.

Shaun Subel, director at VitalityHealth, said: "The findings of the Britain's Healthiest Company research should serve as a wake-up call for UK firms to do more to improve the health and wellbeing of their staff. The data shows that organisations with an authentic and positive culture of wellness see increased productivity from their employees. We would therefore urge all companies, big or small, to protect their bottom line by taking an active role in improving employee wellbeing."