Costs of treating patients increase with body mass index
28 January 2014
A study by US healthcare provider Duke Medicine has found that
health care costs increase in parallel with body mass measurements,
even beginning at a recommended healthy weight. Pharmacy and medical
costs may even double for obese people compared with those at a
The researchers found that costs associated with medical and drug
claims rose gradually with each unit increase in body mass index
(BMI). Notably, these increases began above a BMI of 19, which falls
in the lower range of the healthy weight category. The study was
published in the journal Obesity.
“Our findings suggest that excess fat is detrimental at any
level,” said lead author Truls Østbye MD PhD, professor of community
and family medicine at Duke and professor of health services and
systems research at Duke-National University of Singapore.
A 2013 study published in the Journal of the American Medical
Association, using death data from several large population studies,
concluded that while higher degrees of obesity were associated with
higher mortality rates, being overweight or even slightly obese was
actually linked with lower mortality. Since these findings
questioned the general belief that high body mass leads to poor
health outcomes, Østbye and his colleagues sought to better
understand the rates of obesity-related disease, or morbidity, by
measuring health care utilization and costs.
Using health insurance claims data for 17,703 Duke employees
participating in annual health appraisals from 2001 to 2011, the
researchers related costs of doctors’ visits and use of prescription
drugs to employees' BMIs.
BMI is a measurement of a person’s weight adjusted for his or her
height, and can be used to screen for possible weight-related health
problems. A normal BMI, which suggests a healthy weight, is 19-24,
while overweight is 25-29 and obese is 30 and above. For example, a
5-foot-6-inch person who weighs 117.5 pounds has a BMI of 19, while
a person of the same height weighing 279 pounds has a BMI of 45.
Underweight individuals (who reported a BMI less than 19) were
excluded from this analysis, as very low weight may be a result of
Measuring costs related to doctors’ visits and prescriptions, the
researchers observed that the prevalence of obesity-related diseases
increased gradually across all body mass levels. In addition to
diabetes and hypertension — the two diseases most commonly
associated with being overweight or obese — the rates of nearly a
dozen other disease categories also grew with increases in BMI.
Cardiovascular disease was associated with the largest dollar
increase per unit increase in BMI.
Chart showing how medical care and pharmacy
costs (vertical axis)
increase with BMI units (horizontal axis)
The average annual health care costs for a person with a BMI of
19 was found to be $2,368; this grew to $4,880 for a person with a
BMI of 45 or greater. Women in the study had higher overall medical
costs across all BMI categories, but men saw a sharper increase in
medical costs the higher their BMIs rose.
The study did not find a change in the relationship between
levels of obesity and healthcare costs from 2001 to 2011. In
contrast to the recent evidence relating to mortality, which
concluded that only more obese people were at a higher risk of
death, the current findings suggest that the occurrence of
obesity-related illnesses and related costs begin increasing at a
Given the growing healthcare costs associated with excess weight,
the researchers stressed the importance of implementing effective
health and weight-loss programs.
“The fact that we see the combined costs of pharmacy and medical
more than double for people with BMIs of 45 compared with those of
19 suggests that interventions on weight are warranted,” said
Marissa Stroo, a co-investigator on the study.
The researchers also noted that the workplace is a good setting
for implementing weight loss programs, given that employers can
target the more than 100 million Americans who spend most of their
waking hours at work. The Affordable Care Act recognizes this
advantage, and has created new incentives to promote employee
“Employers should be interested in these findings, because,
directly or indirectly, they end up paying for a large portion of
these healthcare costs,” Østbye said.
The researchers are currently working to evaluate the impact of
employer-sponsored health management and weight loss programs on