Transcript Feeding the World

Feeding the World
 Famine is the widespread malnutrition and starvation
in an area due to a shortage of food, usually caused by
a catastrophic event.
 Modern agriculture practices provide most of the
world’s population with enough food to survive.
 However, some of these practices can cause
environmental damage that eventually makes growing
food crops more difficult.
Humans and Nutrition
 The human body uses food both as a source
of energy and as a source of materials for
building and maintaining body tissues.
 The amount of energy that is available in
food is expressed in Calories. One Calorie is
equal to 1,000 calories or one kilocalorie.
Humans and Nutrition
Humans
and
Nutrition
 Malnutrition is a disorder of nutrition that results when a
person does not consume enough of each of the nutrients
that are needed by the human body.
 Humans need to get 8 essential amino acids from proteins.
This is easily done if a variety of foods is eaten. However, in
some parts of the world, the only sources of food may be
corn and rice, which contain protein, but lacks one of the
essential amino acids. Amino acid deficiency can result
from such a limited diet.
Sources of Nutrition
 Diet is the type and amount of food that a person eats.
A healthy diet is one that maintains a balance of the
right amounts of nutrients, minerals, and vitamins.
 The foods produced in the greatest amounts
worldwide are grains, plants of the grass family whose
seeds are rich in carbohydrates.
 Besides eating grains, most people eat fruits,
vegetables, and smaller amounts of meats, nuts, and
other foods that are rich in fats and proteins.
Your Diet
 Record your diet.
 What did you eat all last week?

Is it Organic?
 What could you change in your diet to be more health?
 What could you supply for yourself at your home with a
garden?
 How much food (percent) do you waste off of your
plate?
Sources of Nutrition
Diets Around the World
 People worldwide generally consume the same major
nutrients and eat the same basic kinds of food.
 Diets vary by region.
 People in more developed countries tend to eat more
food and a larger proportion of proteins and fats than
people in less developed countries.
Diets Around the World
The Ecology of Food
 As the human population grows, farmland
replaces forests and grasslands.
 Feeding everyone while maintaining natural
ecosystems becomes increasingly difficult.
 Different kinds of agriculture have different
environmental impacts and different levels
of efficiency.
Farming
 Should farms produce crops for food or for energy.
 Groups of 4 (write down pros to your side of the
argument)
Food Efficiency
 The efficiency of a given type of agriculture is a
measure of the quantity of food produced on a given
area of land with limited inputs of energy and
resources.
 An ideal food crop is one that efficiently produces a
large amount of food with little negative impact on the
environment.
Food Efficiency
 On average, more energy, water, and land
are used to produced a Calorie of food from
animals than to produce a Calorie of food
from plants.
Food Efficiency
 Thus, a given area of land can usually produce
more food for humans when it is used to grow
plants than when it is used to raise animals.
 The efficiency of raising plants for food is one
reason why diets around the world are largely
based on plants.
 However, meat from animals generally provides
more nutrients per gram than most food from
plants.
World Food Problems
 More food is needed each year to feed the
world’s growing population.
 World food production has been increasing
for decades, but now food production is not
increasing as fast as the human population
is increasing.
World Food Problems
The Green Revolution
 Worldwide, between 1950 and 1970, increases
in crop yields resulted from the use of new
crop varieties and the application of modern
agriculture techniques.
 These changes were called the green
revolution. Since the 1950s, the green
revolution has changed the lives of millions of
people.
The Green Revolution
 In addition, the green revolution had a
negative impact on subsistence farmers, or
farmers who grow only enough food for local
use.
 Before the green revolution, subsistence
farmers worked most of the world’s farms.
 But they could not afford the equipment,
water, ad chemicals needed to grow new
crop varieties.