Ali H. Mokdad, Barbara A. Bowman, Earl S. Ford, Frank Vinicor, James S. Marks, Jeffrey P. Koplan. The Continuing Epidemics of Obesity and Diabetes in the United States. JAMA. 2001;286(10):1195–1200. doi:10.1001/jama.286.10.1195
Author Affiliations: Data Management Division, National Immunization Program (Dr Mokdad); Division of Diabetes Translation (Drs Bowman and Vinicor), Division of Nutrition and Physical Activity (Dr Ford), and Office of the Director (Dr Marks), National Center for Chronic Disease Prevention and Health Promotion; and Office of the Director (Dr Koplan), Centers for Disease Control and Prevention, Atlanta, Ga.
Context Recent reports show that obesity and diabetes have increased in the
United States in the past decade.
Objective To estimate the prevalence of obesity, diabetes, and use of weight control
strategies among US adults in 2000.
Design, Setting, and Participants The Behavioral Risk Factor Surveillance System, a random-digit telephone
survey conducted in all states in 2000, with 184 450 adults aged 18 years
Main Outcome Measures Body mass index (BMI), calculated from self-reported weight and height;
self-reported diabetes; prevalence of weight loss or maintenance attempts;
and weight control strategies used.
Results In 2000, the prevalence of obesity (BMI ≥30 kg/m2) was
19.8%, the prevalence of diabetes was 7.3%, and the prevalence of both combined
was 2.9%. Mississippi had the highest rates of obesity (24.3%) and of diabetes
(8.8%); Colorado had the lowest rate of obesity (13.8%); and Alaska had the
lowest rate of diabetes (4.4%). Twenty-seven percent of US adults did not
engage in any physical activity, and another 28.2% were not regularly active.
Only 24.4% of US adults consumed fruits and vegetables 5 or more times daily.
Among obese participants who had had a routine checkup during the past year,
42.8% had been advised by a health care professional to lose weight. Among
participants trying to lose or maintain weight, 17.5% were following recommendations
to eat fewer calories and increase physical activity to more than 150 min/wk.
Conclusions The prevalence of obesity and diabetes continues to increase among US
adults. Interventions are needed to improve physical activity and diet in
Obesity and diabetes are major causes of morbidity and mortality in
the United States.1,2 Evidence
from several studies indicates that obesity and weight gain are associated
with an increased risk of diabetes.3,4
Each year, an estimated 300 000 US adults die of causes related to obesity.5 Obesity also substantially increases morbidity and
impairs quality of life.6- 8
Overall, the direct costs of obesity and physical inactivity account for approximately
9.4% of US health care expenditures.9 The direct
and indirect costs of health care associated with diabetes in 1997 were an
estimated $98 billion.10
We recently reported that the prevalence of obesity among US adults
(body mass index [BMI; calculated as weight in kilograms divided by the square
of height in meters] ≥30 kg/m2), based on self-reported weight
and height, increased from 1991 to 1999, and that the prevalence of diagnosed
diabetes based on self-reported data increased from 1990 to 1999.11- 14 We
used data from the Behavioral Risk Factor Surveillance System (BRFSS) in 2000
to examine whether these increases in obesity and diabetes are continuing,
the prevalence of attempting to lose or maintain weight, and the strategies
used by the US adults to lose or maintain weight.
The BRFSS is a cross-sectional telephone survey conducted by the Centers
for Disease Control and Prevention and state health departments. The BRFSS
questionnaire consists primarily of questions about personal behaviors that
increase risk for 1 or more of the 10 leading causes of death in the United
States. The BRFSS uses a multistage cluster design based on random-digit dialing
methods of sampling to select a representative sample from each state's noninstitutionalized
civilian residents aged 18 years or older. Data collected from each state
are pooled to produce nationally representative estimates. A detailed description
of the survey methods has been previously published.15,16
We used data on self-reported weight and height to calculate BMI. Participants
were classified as obese if their BMI was 30 kg/m2 or more.17 Extreme obesity (obesity class III) was classified
as a BMI of 40 kg/m2 or more.18
Self-reported weight and height were assessed by asking respondents, "About
how much do you weigh without shoes?" and "About how tall are you without
shoes?" Diagnosed diabetes was assessed by asking respondents, "Have you ever
been told by a doctor that you have diabetes?" The answer was coded "yes"
or "no;" to parallel the methods in our previous reports, respondents who
answered yes include those with gestational diabetes. Classification of diabetes
(type 1 or type 2) was not assessed. The questions on self-reported weight
and height and self-reported diabetes did not change from 1991 to 2000.
Participants were asked to report the type, duration, and frequency
of the 2 leisure-time physical activities they had participated in most frequently
in the past month. These questions were used to create a leisure-time physical
activity score: (1) inactive; (2) irregularly active; (3) regular, not intense;
and (4) regular, intense.19
Respondents were asked, "Are you trying to lose weight?" Those who responded
"no" were asked, "Are you trying to maintain weight?" Respondents who answered
"yes" to either question were asked the following: (1) "Are you trying to
eat fewer calories or less fat to lose weight?", (2) "Are you using physical
activity or exercise to lose weight or keep from gaining weight?", and (3)
"In the past 12 months, has a doctor, nurse, or health professional given
you advice about your weight?"
The 2000 BRFSS questionnaire included the fruit and vegetable module.
We used these questions to classify participants into 4 groups based on fruit
and vegetable daily consumption: (1) less than once or not at all, (2) 1 to
less than 3 times, (3) 3 to less than 5 times, and (4) 5 or more times.
To account for the complex sampling design, SAS and SUDAAN software
programs were used in the analyses.20,21
The 2000 BRFSS is based on responses from 184 450 participants
in 50 states. In 2000, the prevalence of obesity was 19.8% among US adults
(Table 1), which reflects a 61%
increase since 1991.11 A total of 38.8 million
US adults were obese (19.6 million men and 19.2 million women), and approximately
2.1% (1.5% of men and 2.8% of women) of all participants had a BMI of 40 kg/m2or more, compared with 0.9% in 1991 (data available from the author).
In 2000, most US adults—approximately 56.4% (65.5% of men and 47.6%
of women) of all participants—were overweight (BMI ≥25 kg/m2), compared with 45% in 1991 (data available from the author).
In 1991, 4 of the participating states had obesity rates of 15% or greater,
whereas by 2000, all participating states except Colorado had rates of obesity
of 15% or greater (Figure 1 and Table 2). In 1991, none of the participating
states had obesity rates of 20% or greater; however, by 2000, 22 of the participating
states had rates of obesity of 20% or greater. In 2000, Mississippi had the
highest (24.3%) and Colorado had the lowest (13.8%) rate of obesity. Among
races, blacks had the highest rate of obesity (29.3%) (Table 1).
The prevalence of a self-report of diagnosed diabetes increased from
4.9% in 199013 to 7.3% in 2000 (Table 1), a 49% increase. In 2000, approximately 15 million US adults
aged 18 years or older had diagnosed diabetes (6.3 million men and 8.7 million
women). In 1990, 4 states had diabetes rates of 6% or greater, whereas by
2000, 43 of the 50 participating states had diabetes rates of 6% or greater
(Figure 2). In 2000, Mississippi
had the highest rate (8.8%) and Alaska had the lowest rate (4.4%) of diagnosed
diabetes. Blacks had the highest rate of diagnosed diabetes (11.1%) among
all race groups, and participants with less than a high school education had
the highest rate (12.9%) among the educational levels (Table 1). In 2000, 2.9% of US adults both were obese and had diabetes,
compared with 1.4% in 1991 (data available from the author).
Weight control practices varied by BMI. While most participants were
trying to lose or maintain weight, 20.1% of overweight participants and 13.5%
of obese participants were not trying to lose or maintain weight (Table 3). About 27% of US adults did not
engage in any physical activity, and another 28.2% were not regularly active.
Only 24.4% of US adults ate fruits and vegetables at least 5 times a day.
Among obese participants who were trying to lose weight, only 42.8% had been
advised to lose weight by a health professional, and 15.6% of overweight participants
had received such advice.
Among participants who were trying to lose or maintain weight, 72.9%
reported dieting, and 59.5% were increasing physical activity (Table 4). However, among participants attempting to lose or maintain
weight, only 17.5% were following the 2 key recommendations: to eat fewer
calories and to increase physical activity. Similarly, only 24.9% of these
participants were consuming the recommended 5 servings of fruits and vegetables,
while 40.6% were achieving the recommended physical activity levels (30 minutes
of moderate activity 5 times/wk).
During the 1990s, epidemics of obesity and diabetes developed among
US adults. Our current findings indicate that most US adults (>56%) are overweight,
about 1 in 5 is obese, and 7.3% have diabetes. However, if undiagnosed diabetes
is considered, it is likely that almost 10% of US adults have diabetes based
on a previous report that estimated the prevalence of diagnosed diabetes in
1988-1994 to be 5.1% for US adults aged 20 years or older; in this study,
the prevalence of undiagnosed diabetes was 2.7%.22
Our estimates of the extent of the 2 epidemics of obesity and diabetes
in US adults are conservative. In validation studies of self-reported weight
and height, overweight subjects tend to underestimate their weight, and all
participants tend to overestimate their height.23- 25
Moreover, persons without telephones are likely to be of lower socioeconomic
status, a factor associated with increased risk for both obesity and diabetes.22,26
Both BMI and weight gain are major risk factors for diabetes.27,28 Body mass index is one of the strongest
predictors of diabetes, and previous studies have shown that changes in BMI
at the population level foreshadow changes in diabetes.3,4,29- 32
For every 1-kg increase in measured weight, the risk of diabetes increased
by 4.5% in a national sample of adults.3 In
our previous BRFSS analysis for 1991-1998, every 1-kg increase in average
self-reported weight was associated with a 9% increase in the prevalence of
diabetes.13 From 1999 to 2000, the average
weight of US adults increased by 0.5 kg (data available from the author),
and the prevalence of diagnosed diabetes increased by about 6%.14
Both obesity and diabetes are largely preventable. Previous studies
have demonstrated that changes in lifestyle are effective in preventing diabetes
and obesity in selected groups of adults who are at high risk.33- 35
In a recent clinical trial from Finland, lifestyle changes significantly reduced
the risk of diabetes in middle-aged, overweight subjects.35
After a modest (4.7%) weight loss, those in the intervention group had a 58%
reduction in incidence of diabetes over 4 years.35
Moreover, blood pressure, triglycerides, and high-density lipoprotein cholesterol
levels also improved significantly.35 Therefore,
increasing physical activity, improving diet, and sustaining these lifestyle
changes can reduce the risk of both diabetes and increased weight.
The weight-related behaviors of US adults are clearly linked to these
continuing epidemics. We found that 27.0% of US adults in 2000 did not engage
in any leisure-time physical activity, and another 28.2% were not regularly
active. These rates are similar to those reported for 1998 (28.6% inactive
and 28.2% irregularly active).11 In 2000, 38.5%
of US adults were trying to lose weight, 35.9% were trying to maintain weight,
and 25.6% were doing neither. In 1996, these rates were 36.6%, 34.4%, and
29.0%.36 Furthermore, only 24.4% of US adults
met recommendations for fruit and vegetable consumption in 2000 vs 22.7% in
our previous report on BRFSS participants from 16 states in 1996.37
Strategies that US adults use to lose or maintain weight contribute
to their failure to achieve their weight control objectives. In 2000, 72.9%
of US adults reported that they had changed their diet to achieve their weight
goal, and 59.5% reported that they had increased their physical activity.36 These rates have not changed substantially since
1996. Furthermore, in the year 2000, only 17.5% of US adults were following
guidelines for increasing physical activity and lowering energy intake. Although
this percentage has increased from 15.0% in 1996, it is still far below what
will be needed to attain goals for healthy weight.
Our finding that only 42.8% of obese persons who had had a routine checkup
in the past year had been advised by health care professionals to lose weight
is disturbing. In 1996, this percentage was 42.4%, which prompted a call for
physicians to be more involved in weight counseling.38,39
Persons who receive advice from a health care professional to lose weight
are more likely to attempt to lose weight than those who do not receive this
advice.38 Health care professionals should
assess overweight and obesity and recommend weight loss (using the combination
of a low-calorie diet and increased physical activity) to overweight and obese
patients and weight maintenance to patients with normal weight.18
While overweight and obese individuals need to reduce their energy intake
and increase their physical activity, many others must play a role to help
these individuals and to prevent further increases in obesity and diabetes.
That is, health care professionals must counsel their overweight and obese
patients; workplaces must offer healthy food choices in their cafeterias and
provide opportunities for employees to be physically active on site; schools
must offer more physical education that encourages lifelong physical activity;
urban policymakers must provide more sidewalks, bike paths, and other alternatives
to cars; and parents need to reduce their children's television and computer
time and encourage active play. In general, restoring physical activity to
our daily routines is crucial to the future reduction of diabetes and obesity
in the US population.
Unfortunately, the prevalence of obesity and diabetes has increased
despite previous calls for action40; it is
likely to continue to increase in the years ahead unless effective interventions
are implemented. In the past 25 years, several promising approaches have been
identified as targets for clinical and public health action. To control these
dual epidemics, now is the time for implementing multicomponent interventions
for weight control, healthy eating, and physical activity.