Factors Affecting Demand for Food

Text extracted fromThe World Food ProblemLeathers & Foster, 2004

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Age Structure

• Population Pyramids – indicate age structure

• Developing countries – have much higher

percentage of young people

• Developed countries – have even distribution

of age groups

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Momentum• Changes in age

structure affect population for decades– Example: Baby Boom

• If a developing country achieves replacement fertility rates for adults– Population growth

continues for decades – Because there are more

childrenBaby boom age pyramid

Age structure for China (1990)

Great Leap Forward Famine, 1959-1960

http://www.iiasa.ac.at/Research/LUC/ChinaFood/images/charts/p_19a_m.gif

Dependency Ratios• Ratio of dependents to

working adults• Burden of dependent

children per adult greater in developing country– Developed nation ex:

• 0.21 children/adult– Developing nation ex:

• .77 chlidren/adult

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Age Structure determines future calorie needs

• Calorie needs are different at different ages

• Age structure allows prediction of future calorie needs – as current population grows up

• Need for food can grow faster than the population – if more adults than children

• Adults require more food

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Other factors affecting future food needs

• Number of Pregnant women• Amount of physical activity• Height of population

– indicates nutrition level

• Population + demand/person + more meat– Huge synergistic effect

Sierra Leone 8 year old girl

More Meat• As incomes rise, people eat

more meat– less cereals

• Meat production requires plant calories

– Average 6:1 conversion ratio

• Developing countries eat 4,224 Calories from plants– 2,255 directly from plants– Plus 315 meat calories

(12.5%)• Requires 1,969 plant calories

to produce meathttp://images.jupiterimages.com/common/detail/20/63/23036320.jpg

More Meat

• If people in developing countries ate 15% meat– Would increase total

plant calories required • to 4,591/person

– Equivalent increase in demand to 8.7% increase in population

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More Meat

• If people in developing nations ate amount of meat eaten in developed nations (27% calories)– Would require 6,200

plant-derived calories– 47% increase

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Optimistic Future Scenario: Next 50 yrs

• Per capita income increases• Population growth of 50%

– Fertility declines• Food supplies keep pace with

demand• Life expectancy increases• Average height increases• Age structure changes toward

fewer children• Food demand grows by 101%Morocco: middle income

country

Same impact if pessimistic future• Self-Correction on impact

with lower quality of life:– If prosperity declines

• Food supply doesn’t keep up with demand

• Population grows more rapidly • Less decline in fertility rates

– But need less food because• Age structure: more children• Average height: less change• Calories per capita low

– Undernutrition• Dietary diversification small

– Impact: 98% growth in food demandSierra Leone mother

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