1. Feeding the World
CHAPTER 14

2. Human Nutrition
Humans need energy to grow, move, and repair our bodies.
All humans belong to one species – so our dietary requirements are the same.
Nutrients are divided into two groups:
Macronutrients
Micronutrients

3. Nutrients
Macronutrients provide the energy (fuel) our bodies need to function (proteins, carbohydrates and fats)
Micronutrients are small amounts of chemicals needed for our body’s biochemical reactions
kcal kilocalories is how macronutrients are measured
1 kcal = the amount of energy needed to raise 1 kilogram of water 1 degree Celsius

4. Carbohydrates Made of carbon (C), hydrogen (H) and oxygen (O)
Ratio of 1C:2H:1O
Ex: glucose (sugar) = C6H12O6
Basic Building block is sugar or simple carbohydrate
Many sugars put together are called starches or complex carbohydrates
All carbs provide 4 kcal/gram energy

5. Proteins Made of amino acids Amino acids have Nitrogen
Proteins are very large molecules
Hair, skin, blood, muscle, nails
All the proteins in your body are made of just 20 amino acids in different combinations
We can make 12 amino acids – the other 8 we get from our food
Protein gives 4 kcal per gram of energy

6. Lipids Lipids are 3 fatty acids with an alcohol molecule
Lipids make up all cell membranes and lining for all our nerves
Two kinds of lipids:
Solid or hydrogenated at room temperature – butter lard (animal- based fats)
Liquid or dehydrogenated at room temperature – olive oil, canola oil, corn oil (plant-based fats)
Lipids provide 9 kcal of energy per gram

7. Vitamins and Minerals Vitamins and Minerals are Micronutrients
Important in biochemical reactions that release energy in our bodies
Most micronutrients are found in minimally processed fruits and vegetables

8. Nutritional Deficiency
Average adult requires kcalories per day
Adults that receive 90% or less of this requirement are undernourished
Adults that receive less than 80% of the 2500 kcal per day are seriously undernourished
Children that receive less than 90% can suffer permanent damage to bones, teeth, brain function

9. World Food Supply
Research and development in agriculture have increased the amount of food produced
Economics is the driving force behind agricultural production
More crops = more money
Green Revolution (1960’s) new strains of wheat and rice
Wheat and rice are the diet basis for most of the world

10. Green REVOLUTION
New strains of wheat and rice were disease resistant and could adapt to many climates
Designed to help feed underfed nations
Used modern machinery to plant and harvest r- giving 4X the crops from the same farmland
PROBLEMS: poorest nations didn’t have money for machines, fuel or fertilizers – so only developed countries used the technology

11. Cash Crops More wheat and rice mean lower prices
Poor farmers were paid even lower prices for their small harvests
ANSWER: grow more expensive crops that can be exported to richer countries who will pay for them
CASH CROP – crops grown only for sale – not to feed the farmer or the community

12. Aquaculture
Food doesn’t just come from the land – the hydrosphere produces 200 billion tons of biomass each year
Commercial fishing has endangered over 40 of 280 fish species
ANSWER: aquaculture – raising fish and shellfish in salt or freshwater pools or ponds
PROBLEMS: water becomes contaminated with run-off and chemicals used to feed fish

13. Hydroponics
Water isn’t just used for fish – plants can also be grown in water
Hydroponics – plants grown without soil
In the produce section of the supermarket: tomatoes, lettuce, peppers, radishes, cucumbers, herbs and flowers grown without soil in controlled conditions using nutrient solutions and recycled water
Usually pesticide free because grown in controlled conditions indoors

14. Modern Farming Techniques
Huge farm machinery has replaced man and animal labor
Middle of 20th century-began to use machines powered by fossil fuels
Called “Industrialized Agriculture”
Efficient and productive
Require large amount of energy, pesticides, fertilizers.
Often run by corporations (agribuisinesses).

15. Agribusiness Problems
Use of pesticides
Increase in resistant insects and other pests.
1992-California white fly infestation
DDT and decline in bald eagle population
Monoculture
Farms growing only the 1 or 2 crops that bring in the most money.
Crops genetically identical = more vulnerable to disease
Soil depleted of minerals = soil loses ability to produce healthy crop.
Ex: Russet Burbank potatoes

16. “Ancient” Grains Quinoa New grains Not adapted to local conditions
Looking to use local grains in many areas
Ex: quinoa – grows better than wheat or rice in mountainous areas, high in protein, can be made into flour, cereal, beverages and livestock feed.
Faro, Spelt, Flax, Buckwheat

17. Sustainable Agriculture
Modern agriculture has resulted in: soil erosion, deforestation, desertification, hunger, war, and environmental damage.
Sustainable agriculture-called regenerative farming; based on crop rotation, reduced soil erosion, pest management, and minimal use of soil additives.

18. Crop Rotation
Crop Rotation- changing the type of crop grown in an area on a regular cycle.
Usually 1 to 6 years per cycle
Prevent soil from becoming depleted of nutrients (nitrogen).
Avoid use of synthetic fertilizers.
Cover Crop- nonfood plants grown between grown seasons on land usually left empty.
Restore nitrogen to the soil and help to reduce erosion

19. Reducing erosion
Erosion- process where soil is lost, transported, and reformed. Caused by wind and flowing water.
When topsoil removed, loss of nutrients= useless for farming.
Can be reduced by irrigation and soil management.
Irrigation-watering of fields; use systems that deliver less water, but directly to the roots reduces erosion.
Tilling-turning the soil so lower layers are brought to the surface.
Destroys weeds and other pests, brings nutrients to the surface, improves drainage, and aerates the soil.
Wastes water, uses energy, can increase erosion.

20. Irrigation

21. Tilling

22. Pest Management We LOVE Ladybugs! Integrated Pest Management (IPM)
Reduce pesticide use by 90%
Use natural predators to manage pests (ex: wasps, ladybugs, viruses and bacteria, etc)