Factors Affecting Demand for
Food
Text adapted from
The World Food Problem
Leathers & Foster, 2009
ttp://www.amazon.com/World-Food-ProblemToward-Undernutrition/dp/1588266389
Age Structure
• Population Pyramids
– indicate age structure
• Developing countries
– have much higher
percentage of young
people
• Developed countries
– have even distribution
of age groups
http://www.scalloway.org.uk/images/poppy1.jpg
http://www.scalloway.org.uk/images/poppy2.jpg
Momentum
• Changes in age
structure affect
population for decades
– Example: Baby Boom
• If a developing country
achieves replacement
fertility rates for adults
Baby boom age pyramid
– Population growth
continues for decades
– Because there are more
children
Age structure for China (1990)
Great Leap
Forward
Famine, 19591960
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
http://www.scalloway.org.uk/images/poppy1.jpg
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
http://www.scalloway.org.uk/images/poppy2.jpg
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 meat
http://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
http://delishfood.files.wordpress.com/2007/10/img_4381.JPG
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
http://i157.photobucket.com/albums/t49/cinzia326/7025.jpg
Optimistic Future Scenario:
Next 50 yrs
• Per capita income increases
• Population growth of 50%
– Fertility declines
• Food supplies keep pace with
•
•
•
Morocco: middle income
country
•
demand
Life expectancy increases
Average height increases
Age structure changes toward
fewer children
Food demand grows by 101%
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
Sierra Leone mother
http://www.voices-unabridged.org/photo_gala/gala_dec_2006_pt_18.jpg
• Dietary diversification small
– Impact: 98% growth in food
demand