Businesses have been warned to take more interest in the weight of their employees if they want to avoid increased insurance premiums and producitivy losses.

The advice comes after research carried out in the United States revealed US employers were currently losing more than $12 billion (£6.4 billion) a year due to the consequences of obesity, such as increased absenteeism and rocketing health and disability premiums.

Indeed, the US has witnessed a staggering ten-fold increase in the incidence of disability claims attributed to obesity over the past decade.

According to Dr Michael O'Donnell, chief medical officer for group income insurer UnumProvident, which commissioned the research: "In the UK, it has been estimated that obesity costs the NHS £500m a year in in-patient care and that the cost to the wider UK economy through sickness absence is already £2 billion.

"Considering the impact obesity has on US employees, we feel strongly UK businesses should act now to help their workforce control this life-threatening condition, which is caused not only by diet but a more sedentary lifestyle."

Research also showed US employees diagnosed as obese enjoyed a significantly higher number of medical services than their slimmer colleagues for example, obese employees required 36 times more medical services due to problems with their circulatory systems than non-obese employees.

Added Dr O'Donnell: "The implementation of strategies by businesses could be a valuable part of an overarching public health approach for the prevention and treatment of obesity."

Dennis Grant, chief executive of Swindon Chamber of Commerce, agreed employers should do more to ensure their staff stayed healthy.

He said some businesses could even be contributing to the obesity crisis.

He said: "Employers have a duty of care toward their employees and so should try and help them avoid such health conditions as obesity.

"Because, in a way, they have contributed to the problem.

"British workers work such long hours, they rarely have the opportunity to put enough time aside to exercise.

"That doesn't mean employers have to nanny their staff, but maybe introduce initiatives that encourage their staff to stay fitter."