Having a body mass index in the overweight or obese
range increases the risk of traumatic workplace injury,
according to researchers at the Johns Hopkins Bloomberg
School of Public Health's
Center for Injury Research and Policy. Because of this,
the researchers say, employer-sponsored weight loss and
maintenance programs should be considered as part of a
well-rounded workplace safety plan. The study was an
Advance Access paper published May 7 by the American
Journal of Epidemiology.
Body mass index, known as BMI, is a measure of body
fat based on an adult's height and weight. It is used to
screen for weight categories that may lead to health
problems. According to the Centers for Disease Control and
Prevention, a BMI below 18.5 is considered underweight,
18.5 to 24.9 is normal, 25 to 29.9 is overweight, and over
30 is obese.
"Clearly, limited resources for workplace injury
prevention and control should target the most prominent and
modifiable risk factors, but we cannot neglect the fact
that our study and other recently published studies support
an association between BMI and the risk, distribution and
prevalence of workplace injury," said Keshia M. Pollack,
lead author of the study and an assistant professor in the
Bloomberg School's Department
of Health Policy and Management.
The researchers used medical and injury surveillance
data on hourly workers employed in eight plants of the same
aluminum manufacturer to determine whether increased BMI
was a risk factor for workplace injury. The plants were
scattered across the United States. BMI was calculated
using National Institutes of Health criteria. Employees
were grouped into five categories: underweight, normal,
overweight, obesity levels I and II and obesity level
Of the 7,690 workers included in the study, 29 percent
were injured at least once between Jan. 2, 2002, and Dec.
31, 2004. Approximately 85 percent of the injured workers
were classified as overweight or obese. More than 28
percent of injuries occurred among employees classified as
overweight, 30 percent in the obese I and II category and
almost 34 percent in the obese III category.
The severely obese group who had a BMI of greater than
40 also had the most injuries to the hand/wrist/finger (22
percent) when compared to the same injuries in the other
weight categories. Almost 10 percent of all injuries in the
obese III group were to the leg/knee, compared to 7 percent
of workers classified as overweight, which was the next
highest injury rate.
"We know that obesity prevention policies and programs
in the workplace are important simply because of likely
improvements in employee health," said Pollack, the Leon S.
Robertson Faculty Development Chair in Injury Prevention.
"What we do not know is if obesity prevention in the
workplace will also have the added benefit of improving
injury rates and reducing lost work time. Evaluations of
worksite health promotion and obesity prevention efforts
should measure changes not only in employee health but also
The researchers say that more work will be needed to
test the effectiveness for reducing weight among hourly
(nonoffice) employees who face a number of barriers to
participating in worksite physical activity programs, such
as the need to remove protective clothing for midday
exercise and a lack of time because of additional
employment or home responsibilities.
Pollack and Gary S. Sorock, both with the Johns
Hopkins Bloomberg School of Public Health; and Martin D.
Slade, Linda Cantley, Kanta Sircar, Oyebode Taiwo and Mark
R. Cullen, all of Yale University, co-authored the study.
The study was supported by grants from the National
Institute of Diabetes and Digestive and Kidney Diseases,
National Institute of Occupational Safety and Health, NIOSH
Education and Research Center for Occupational Safety and
Health at the JHSPH, Donaghue Foundation and John D. and
Catherine T. MacArthur Foundation Research Network on
Socioeconomic Status and Health. Support was also provided