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December 19, 2000-11
Copyright © 2001 Earth Policy
Institute
Obesity Epidemic Threatens
Health
in Exercise-Deprived Societies
Lester R. Brown
Obesity is reaching epidemic proportions, afflicting
a growing number of people in industrial and developing countries
alike. It is damaging human health, raising the incidence of heart
disease, stroke, breast cancer, colon cancer, arthritis, and adult
onset diabetes. In the United States, the Centers for Disease Control
(CDC) estimates that 300,000 Americans now die each year from obesity-related
illnesses.
Reducing obesity has traditionally focused on
lowering caloric intake by dieting, but there is growing evidence
that exercise deprivation is also a major contributor to obesity.
With metabolic systems shaped by 4 million years of highly active
hunting and gathering, many people may not be able to maintain a
healthy body weight without regular exercise.
For the first time in history, a majority of adults
in some societies are overweight. In the United States, 61 percent
of all adults are overweight. In Russia, the figure is 54 percent;
in the United Kingdom 51 percent; and in Germany 50 percent. For
Europe as a whole, more than half of those between 35 and 65 years
of age are overweight.
The number who are overweight is rising in developing
countries as well. In Brazil, for example, 36 percent of the adult
population is overweight. Fifteen percent of China's adult population
is overweight.
Not only are more people overweight than ever
before, but their ranks are expanding at a record rate. In the United
States, obesity among adults increased by half between 1980 and
1994. Among Americans, 20 percent of men and 25 percent of women
are more than 30 pounds (13.6 kilograms) overweight. Surveys in
China showed that during the boom years between 1989 and 1992, the
share of adults overweight jumped from 9 percent to 15 percent.
Juvenile obesity is rising rapidly. In the United
States, where at least 1 out of 10 youngsters 6 to 17 years of age
is overweight, the incidence of obesity among children has more
than doubled over the last 30 years. Not only does juvenile obesity
typically translate into adult obesity, but it also causes metabolic
changes that make the disease difficult to treat in adulthood.
Obesity is concentrated in cities. As societies
urbanize and people adopt sedentary lifestyles, obesity increases.
In both China and Indonesia, the share of people who are obese in
cities is double that in the countryside. In the Congo, obesity
is six times higher in cities.
In a Worldwatch Paper, Underfed and Overfed, Gary
Gardner and Brian Halweil report that the number who are overnourished
and overweight has climbed to 1.1 billion worldwide, rivaling the
number who are undernourished and underweight. Peter Kopelman of
the Royal London School of Medicine summarizes the thinking of the
medical community: “Obesity should no longer be regarded simply
as a cosmetic problem affecting certain individuals, but [as] an
epidemic that threatens global well being.”
Damage to health from obesity takes many forms.
In addition to the illnesses noted earlier, heavier body weight
increases resistance to the heart's pumping of blood, elevating
blood pressure. It also raises the stress on joints, often causing
lower back pain. Those who are obese are four times as likely to
have diabetes as those who are not.
As weight goes up, life expectancy goes down.
In analyzing this relationship for Americans between the ages of
30 and 42, one broad-based study found that the risk of death within
26 years increased by 1 percent with each additional pound (0.45
kg) of weight.
The estimated 300,000 Americans who die prematurely
each year as a result of being overweight is nearing the 400,000
who die prematurely from cigarette smoking. But there is one difference.
The number of cigarettes smoked per person in the United States
is on the decline, falling some 42 percent between 1980 and 1999;
whereas obesity is on the rise. If recent trends continue, it is
only a matter of time before deaths from obesity-related illnesses
overtake those related to smoking.
Gaining weight is a result of consuming more calories
than are burned. With modernization, caloric intake has climbed.
Over the last two decades, caloric intake in the United States has
risen nearly 10 percent for men and 7 percent for women. Modern
diets are rich in fat and sugar. In addition to sugars that occur
naturally in food, the average American diet now includes 20 teaspoons
of added sugar a day, much of it in soft drinks and prepared foods.
Unfortunately, diets in developing countries, especially in urban
areas, are moving in this same direction.
While caloric intake has been rising, exercise
has been declining. The latest U.S. survey shows that 57 percent
of Americans exercise only occasionally or not at all, a number
that corresponds closely with the share of the population that is
overweight.
Economic modernization has systematically eliminated
exercise from our lives. Workers commute by car from home to work
in an office or factory, driving quite literally from door to door.
Automobiles have eliminated daily walking and cycling. Elevators
and escalators have replaced stairs. Leisure time is spent watching
television. In the United Kingdom, the two lifestyle variables that
correlate most closely with obesity are television viewing and automobile
ownership.
Children who watch television five or more hours
a day are five times as likely to be overweight as those who watch
less than two hours a day. Time spent playing computer games and
surfing the Internet in lieu of playing outside is also contributing
to the surge in obesity.
A common impulse of those who are overweight is
to go on a diet of some sort, attempting to reduce caloric intake
to the level of caloric use. Unfortunately, this is physiologically
difficult given the abnormally low calorie use associated with our
sedentary lifestyles. Ninety-five percent of Americans who attempt
to achieve a healthy body weight by dieting alone fail.
Another manifestation of diet failures is the
extent to which people are turning to liposuction to remove body
fat. Resorting to this risky surgical procedure, which quite literally
vacuums fat from under the skin, is a desperate last measure for
those whose diets have failed. In 1998, there were some 400,000
liposuction procedures in the United States.
For many of those who are overweight, achieving
a healthy body weight depends on both reducing caloric intake and
burning more calories through exercise. Metabolically, we are hunter-gatherers.
Given our heritage, exercise may be a genetic imperative.
Restoring exercise in our daily lives will not
be easy. Today's cities, designed for automobiles, are leading to
a life-threatening level of exercise deprivation. Our health depends
on creating neighborhoods that are conducive to walking, jogging,
and bicycling.
The challenge is to redesign communities, making
public transportation the centerpiece of urban transport, and augmenting
it with sidewalks, jogging trails, and bikeways. This also means
replacing parking lots with parks, playgrounds, and playing fields.
Unless we can design a lifestyle that systematically restores exercise
to our daily routines, the obesity epidemic — and the health
deterioration associated with it — will continue to spread.
Copyright
© 2001 Earth Policy Institute
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FOR ADDITIONAL INFORMATION
From Worldwatch Institute
Gary Gardner and Brian Halweil, “Underfed
and Overfed: The Global Epidemic of Malnutrition,” Worldwatch
Paper 150, (Washington, DC: Worldwatch Institute, 2000).
From Other Sources
William H. Dietz, “Battling Obesity: Notes
from the Front,” National Center for Chronic Disease Prevention
and Health Promotion Chronic Disease Notes & Reports, vol.
13, n. 1, Winter 2000, 2.
J. M. Friedman, “Obesity in the New Millennium,” Nature,
vol. 404, 6 April 2000, 632.
Peter G. Kopelman, “Obesity as a Medical Problem,” Nature,
vol. 404, 6 April 2000, 635.
Jeffrey O. Koplan and William H. Dietz, “Caloric Imbalance
and Public Health Policy,” JAMA (The Journal of the American
Medical Association), vol. 282, n. 16, 27 October 1999, 1579.
National Center for Chronic Disease Prevention and Health Promotion,
“Preventing Obesity Among Children,” Chronic Disease
Notes & Reports, vol. 13, n. 1, Winter 2000, 1.
Ali H. Mokdad et al., “The Continuing Epidemic of Obesity in
the United States,” JAMA, vol. 284, n. 13, 4 October
2000, 1650.
Barry M. Popkin, “Urbanization and the Nutrition Transition,”
Brief 7 in Focus 3: Achieving Urban Food and Nutrition Security
in the Developing World, International Food Policy Research
Institute (IFPRI), August 2000.
World Health Organization, Obesity: Preventing and Managing the
Global Epidemic, Report of a WHO Consultation on Obesity, Geneva,
1997.
LINKS
American Obesity Association
http://www.obesity.org
Centers for Disease Control and Prevention (CDC): Obesity and Overweight hhttp://www.cdc.gov/
nccdphp/dnpa/obesity/
International Obesity Taskforce
http://www.iotf.org/
The New York Times, Health: The Fat Epidemic
http://www.nytimes.com/
library/national/ science/
health/obesity-health.html
World Health Organization (WHO)
http://www.who.int/
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