Several researchers have examined the costs of obesity. The World Bank has
estimated the cost of obesity in the U.S. at 12 percent of the national health
care budget, according to the Worldwatch
Institute.
The American Obesity Association commissioned a cost study in 1999 by the Lewin
Group, a respected health economics consulting firm. The Lewin Group examined
the costs of fifteen (15) conditions causally related to obesity. They included:
arthritis, breast cancer, heart disease, colorectal cancer, type 2 diabetes,
endometrial cancer, end-stage renal disease, gallbladder disease, hypertension,
liver disease, low back pain, renal cell cancer, obstructive sleep apnea, stroke
and urinary incontinence. Utilizing the National Health Interview Survey in
1995 and the third National Health and Nutrition Examination Survey (NHANES
III) databases, they established prevalence rates of each comorbid condition.
For each condition, the percentage of the cost of each disease was determined
through the scientific literature or professional associations and were computed
according to the percent of the costs attributed to obesity. This method established
the direct health care costs of obesity at $102.2 billion in 1999. See Table
1. This study did not examine indirect costs. It should be noted that the study
relied on published data on the costs of the specific comorbid diseases. There
is probably some amount of double-counting in the figure which could not be
adjusted.
Table
1. Obesity Costs in Relation to the Co-Morbidities
(1999 dollars in billions) |
| Disease |
Direct Cost
of Obesity |
Direct Cost
of Disease |
Direct
Cost of Obesity as a Percentage of Total Direct Cost of Disease |
| Arthritis |
$7.4 |
$23.1 |
32% |
| Breast Cancer |
$2.1 |
$10.2 |
21% |
| Heart Disease |
$30.6 |
$101.8 |
30% |
| Colorectal Cancer |
$2.0 |
$10.0 |
20% |
| Diabetes (Type
2) |
$20.5 |
$47.2 |
43% |
| Endometrial Cancer |
$0.6 |
$2.5 |
24% |
| ESRD |
$3.0 |
$14.9 |
20% |
| Gallstones |
$3.5 |
$7.7 |
45% |
| Hypertension |
$9.6 |
$24.5 |
39% |
| Liver Disease |
$3.4 |
$9.7 |
35% |
| Low Back Pain |
$3.5 |
$19.2 |
18% |
| Renal Cell Cancer |
$0.5 |
$1.6 |
31% |
| Obstructive Sleep
Apnea |
$0.2 |
$0.4 |
50% |
| Stroke |
$8.1 |
$29.5 |
27% |
| Urinary Incontinence |
$7.6 |
$29.2 |
26% |
| Total
Direct Cost |
$102.2 |
$331.4 |
31% |
Source: The Lewin Group, 1999.
The Lewin study confirmed results from other studies in finding a direct correlation
between increases in Body Mass Index (BMI) and increases in the prevalence of
comorbid conditions, especially type 2 diabetes, hypertension, heart disease,
stroke and arthritis. See Table 2.
Table
2. Increased Risk of Obesity Related Diseases
with Higher BMI |
| Disease |
BMI
of
25 or less |
BMI
between
25 and 30 |
BMI
between
30 and 35 |
BMI
of
35 or more |
| Arthritis |
1.00 |
1.56 |
1.87 |
2.39 |
| Heart Disease |
1.00 |
1.39 |
1.86 |
1.67 |
| Diabetes (Type
2) |
1.00 |
2.42 |
3.35 |
6.16 |
| Gallstones |
1.00 |
1.97 |
3.30 |
5.48 |
| Hypertension |
1.00 |
1.92 |
2.82 |
3.77 |
| Stroke |
1.00 |
1.53 |
1.59 |
1.75 |
Source: Centers for Disease Control. Third National Health and Nutrition Examination
Survey. Analysis by The Lewin Group, 1999.
Researcher KA Heithoff found that health care expenditure among both underweight
and overweight individuals increased in relation to ideal weight. In 1998, researchers
Wolf and Colditz concluded that the total direct costs attributable to obesity
were $51.64 billion in 1994. However, Wolf and Colditz had fewer comorbid conditions
with economic data than were available to the Lewin Group.
Read the abstract about these studies:
Wolf and Colditz did estimate $47.56 billion in indirect costs in 1994, which
included lost productivity, restricted activity days. Their study concluded
obesity was responsible for about 5.7% of national health expenditures. The
Lewin Group figures would equate to about 9.8% of national health expenditures.
The cost of obesity to U.S. business in 1994, according to a study by David
Thompson and colleagues, was $12.7 billion, including $2.6 billion as a result
of mild obesity and $10.1 due to moderate to severe obesity. Health insurance
expenditures constituted $7.7 billion of the total, representing 43% of all
spending by U.S. business on coronary heart disease, hypertension, type 2 diabetes,
hypercholesterolemia, stroke, gallbladder disease, osteoarthritis of the knee
and endometrial cancer. Obesity-attributable business expenditures on paid sick
leave, life insurance and disability insurance amounted to $2.4 billion, $1.8
billion and $800 million respectively. Given methodological differences, these
findings are consistent with numerous other studies.
Read the abstract about these studies:
Global studies reflect results from more local settings. In a study by Quesenberry
and colleagues of members of a large HMO, an association was found between BMI
and additional annual inpatient days and costs of outpatients visits, costs
of outpatient pharmacy and laboratory and total costs. Findings from a study
by Tucker and Friedman found that obese employees were more than 1.74 as likely
to experience high-level absenteeism and 1.61 times more moderate absenteeism
than were lean employees. These findings were similar to that of Burton and
colleagues.
Read the abstract about these studies:
Burton and his colleagues also found that as BMI increased so did the number
of sick days, medical claims and health care costs. The mean annual health care
costs were $2,274 for individuals above a BMI of 27 and $1,499 for workers below
that level. The researchers suggest, "Employers may benefit from helping employees
achieve a healthier weight."
Effectiveness of weight loss interventions
Weight loss interventions work and will result in the reduction of many of
the comorbid diseases associated with obesity. Weight loss involves more than
a choice of foods. Research indicates that effective weight loss interventions
including surgery and pharmacology, use behavior modification to promote healthier
lifestyle.
In 1998, the National Institutes of Health (NIH) issued comprehensive Clinical
Guidelines on the Identification, Evaluation, and Treatment of Overweight and
Obesity in Adults. The NIH recommended treating overweight and
obesity based "not only on evidence that relates obesity to increased mortality
but also on RCT (randomized clinical trials) evidence that weight loss reduces
risk factors for disease. Thus weight loss not only may help control diseases
worsened by obesity, it may also help decrease the likelihood of developing
these diseases."
Based exhaustive reviews of numerous studies, the NIH made several recommendations
including the following:
- "Weight loss is recommended to lower elevated blood pressure in overweight
and obese persons with high blood pressure.
- Weight loss is recommended to lower elevated levels of total cholesterol,
LDL-cholesterol and triglycerides and to raise low levels of HDL-cholesterol
in overweight and obese persons with dyslipidemia.
- Weight loss is recommended to lower elevated blood glucose levels in overweight
and obese persons with type 2 diabetes.
- The combination of a reduced calorie diet and increased physical activity
is recommended, since it produces weight loss, decreases abdominal fat, and
increases cardiorespiratory fitness.
- Behavior therapy is a useful adjunct when incorporated into treatment for
weight loss and weight maintenance."
A study by Noel and colleagues of primary care physician practices in Michigan
confirmed that "a modest weight loss of 15 pounds per person would markedly
reduce the prevalence of overweight and severely overweight in our patients
from 53% to 38% and from 28% to 18%, respectively."
Cost effectiveness of weight loss interventions.
At this point, we have a clear understanding that:
- obesity causes many major health conditions, such as type 2 diabetes and
heart disease,
- obesity causes high level of both direct and indirect health care expenditures,
and
- weight loss interventions are effective in both reducing weight and in the
reduction of comorbid conditions.
The next question is, "Do those reductions in weight and comorbid conditions
translate into reductions in cost?" While the answer to this question appears
straightforward, it has not been studied in detail and assumptions may be mitigated
by the difficulties in sustaining weight loss over time.
However, Oster and colleagues developed an encouraging model based on the relationship
between BMI and the risks and costs of five obesity-related diseases. The researchers
then calculated the lifetime health and economic benefits of a sustained 10%
reduction in body weight from men and women, aged 35 to 64 with mild, moderate
and severe obesity. They found that a sustained 10% weight reduction would:
- reduce the expected number of years of life with hypertension by 1.2 to
2.9 years, with hypercholesterolemia by 0.3 to 0.8 year, and with type 2 diabetes
by 0.5 to 1.7 year,
- reduce the expected lifetime incidence of coronary heart disease by 12
to 38 cases per 1000,
- reduce stroke by 1 to 13 cases per 1,000,
- increase life expectancy by 2 to 7 months, and,
- reduce expected lifetime medical care costs of these five disease by $2,200
to $5,300.
Surgical treatment of obesity results in a reduction of sick leave and disability
pension according to a study by Narbro and colleagues, who compared gastric
bypass surgery patients to a control group in Sweden. The researchers found
that before surgery, the number of sick-days plus disability pension was similar
between controls and subjects. After surgery, the patients had more sick days
in the first year but fewer days of sick leave in the second, third and fourth
years in which they were followed.
