The latest research is suggesting that obese workers are more costly to their employers.
It seems they use more workers' compensation claims for injuries on the job, and are more likely to go on to become disabled.
Workers' compensation plans vary from state to state but all require employers to have insurance policies which cover their employees should they be injured on the job.
The insurance pays for the employee's medical costs, compensation for loss of current or future wages, or compensation for pain and suffering.
The research also found that obese workers in high-risk jobs incurred the highest costs, both economically and medically.
According to two reports published in the Archives of Internal Medicine, employers need to consider offering advice not only on safe work practices, but on healthy eating and exercise.
Dr. Truls Ostbye and colleagues at Duke University Medical Center in North Carolina studied 11,728 health care and university employees who completed at least one health risk assessment questionnaire between 1997 and 2004.
Currently a person is considered technically obese if he or she has a body mass index (BMI) of 30 or above; BMI is calculated as weight in kilograms divided by height in meters squared.
Obesity is known to increase the risk of cancer, heart disease and diabetes.
The researchers found that over an average of three years, workers with higher BMIs tended to file more workers' compensation claims, while those with BMIs of 40 or more had twice the rate of claims as people at recommended weights.
Those claims were especially related to back, wrist or arm, neck or shoulder, knee, foot or hip injuries.
Dr. Ostbye, a professor of community and family medicine, says the number of lost workdays was almost 13 times higher, medical claims costs were seven times higher and indemnity claims costs were 11 times higher among the heaviest employees, compared with those of recommended weight.
Ostbye says given the strong link between obesity and workers' compensation costs, maintaining healthy weight is not only important to workers but should also be a high priority for employers.
In the second study, Dr. Soham Al Snih of the University of Texas Medical Branch in Galveston and colleagues studied 12,725 adults 65 years or older.
At the start of the study in 1982 none were disabled; the study ended in 1993.
On a yearly basis the researchers questioned the volunteers about health conditions, demographics and psychosocial characteristics; blood pressure, height, weight and physical function were also measured.
Over the 11 year period, 3,570 of the volunteers became disabled, and 2,019 died.
The researchers say those with BMIs of lower than 18.5 (underweight) or 30 or higher (obese) at baseline were significantly more likely to experience disability during the follow-up period.
However the team say that being simply overweight did not cause health trouble as those with BMIs of 25 to 30, 150 pounds to 180 pounds (68 to 82 kilograms) measuring 5 feet 5 inches, lived longer than people who weighed less.
The researchers say the disability-free life expectancy is greatest among subjects with a BMI of 25 to less than 30.
This result supports other studies which have also found underweight and normal weight older adults may have a lower immediate risk of death.