Food, Soil, and Pest Management - Environmental Science - page 219

Other nutritional deficiency diseases are caused by
a lack of minerals. Too little iron —a component of the
hemoglobin that transports oxygen in the blood—
causes anemia. According to a 1999 survey by the WHO,
one of every three people in the world—mostly women
and children in tropical developing countries—suffers
from iron deficiency. This condition causes fatigue,
makes infection more likely, and increases a woman's
chances of dying in childbirth and an infant's chances
of dying of infection in its first year of life.
Elemental iodine is essential for proper functioning
of the thyroid gland, which produces a hormone that
controls the body's rate of metabolism. Iodine is found
in seafood and crops grown in iodine-rich soils.
Chronic lack of iodine can cause stunted growth, men-
tal retardation, and goiter—an abnormal enlargement
of the thyroid gland that can lead to deafness. Accord-
ing to the United Nations, 26 million children suffer
brain damage each year from lack of iodine. Approxi-
mately 600 million people—mostly in South and
Southeast Asia—suffer from goiter.

Overnutrition occurs when food energy intake exceeds
energy use and causes excess body fat. Too many calo-
ries, too little exercise, or both can cause overnutrition.
People who are underfed and underweight and
those who are overfed and overweight face similar
health problems: lower life expectancy, greater susceptibil-
ity to disease and illness, and lower productivity and life
quality. We live in a world where 1 billion people have
health problems because they do not get enough to eat
and another 1.2 billion worry about health problems
from eating too much. According to 2004 study by the
International Obesity Task Force, one of every four
people in the world is overweight and 5% are obese.
In developed countries, overnutrition causes pre-
ventable deaths, mostly from heart disease, cancer,
stroke, and diabetes. According to the U.S. Centers for
Disease Control and Prevention (CDC), almost two-
thirds of Americans adults are overweight or obese—
the highest overnutrition rate in any developed coun-
try. The $40 billion that Americans spend each year
trying to lose weight is 1.7 times more than the $24 bil-
lion per year needed to eliminate undernutrition and
malnutrition in the world.
A study of thousands of Chinese villagers indi-
cates that the healthiest diet for humans is largely veg-
etarian, with only 10-15% of calories coming from fat.
This stands in contrast to the typical meat-based diet,
in which 30-40% of calories come from fat.
In 2004, the WHO urged governments to discour-
age food and beverage ads that exploit children; tax
less-healthy foods; and limit the availability of high-fat
and high-sugar foods in schools.

Solutions: Reducing Hunger
and Malnutrition
There are several ways to reduce childhood deaths
from nutrition-related causes.
Studies by the United Nations Children's Fund
(UNICEF) indicate that one-half to two-thirds of child-
hood deaths from nutrition-related causes could be
prevented at an average annual cost of $5-10 per child
by the following measures:

■ Immunizing children against childhood diseases
such as measles
■ Encouraging breast-feeding (except for mothers
with AIDS)
■ Preventing dehydration from diarrhea by giving
infants a mixture of sugar and salt in a glass of water
■ Preventing blindness by giving children a vitamin
A capsule twice a year at a cost of about 75¢ per
child, or fortifying common foods with vitamin A and
other micronutrients at a cost of about 10¢ per child
annually
■ Providing family planning services to help moth-
ers space births at least 2 years apart
■ Increasing education for women, with emphasis
on nutrition, drinking water sterilization, and child
care

Science: Environmental Effects
of Producing Food
Modern agriculture has a greater harmful
environmental impact than any human activity, and
these effects may limit future food production.
Modern agriculture has significant harmful effects on
air, soil, water, and biodiversity, as Figure 10-18 (p. 220)
shows. According to many analysts, agriculture has a
greater harmful environmental impact than any hu-
man activity!
Some analysts believe these harmful environmen-
tal effects can be overcome and will not limit future
food production. Other analysts disagree. For exam-
ple, according to environmental expert Norman My-
ers, a combination of environmental factors may limit
future food production. They include soil erosion, salt
buildup and waterlogging of soil on irrigated lands, water
deficits and droughts, and loss of wild species that provide
the genetic resources for improved forms of foods.
According to a 2002 study by the UN Department
for Economic and Social Affairs, nearly 30% of the
world's cropland has been degraded to some degree

Science and Affluence: Eating Too Much
Unhealthy Food
Overnutrition is a cause of poor health and
preventable deaths.