Peter Stevenson

Feeding nine billion: how much extra food do we need to produce?

By : Peter Stevenson
Jun 13, 2013

Experts regularly argue that, in order to feed the anticipated world population in 2050 of nine billion, food production must increase by 60%-70% or more.  And on the basis of these figures we are told that further intensification of agricultural production is essential.

But are these figures accurate?  Do we really need to produce so much extra food? writes Peter Stevenson.

Studies suggest that on average we need 2,500 kilocalories (kcal) each per day.  A UNEP report cites research showing that the world’s total edible crop harvest could supply 4,600 kcal per person per day.[i]  However, of this 1,400 kcal is lost or wasted.

A further 1,700 kcal is used as animal feed.  But – crucially – the resultant meat and dairy products only provide 500 kcal for human consumption.  In effect, 1,200 kcal is lost in the poor return achieved by feeding human-edible crops to animals.  Only 30% of the calories fed to animals in the form of human-edible crops is returned for human consumption as meat or dairy products. 

UNEP also produced its own even more disquieting calculations.  It estimates that each kilo of cereals contains 3,000 kcal.  It calculates that 3 kg of cereals are needed to produce 1 kg of animal products and that each kilogram of animal product contains half the calories provided by 1 kg cereals (roughly 1,500 kcal per kg meat).  Accordingly, each kilo of cereals used for animal feed will produce 500 kcal for human consumption, whereas if used for direct human consumption it will give 3,000 kcal. 

How many more people could be fed if human-edible crops used as animal feed were reallocated for human consumption?

UNEP calculates that the cereals that, on a business-as-usual basis, are expected to be fed to livestock by 2050 could, if they were instead used to feed people directly, provide the necessary food energy for more than 3.5 billion people. If we halved the amount of cereals that would be used for feed by 2050, an extra 1.75 billion people could be fed.

How many more people could be fed if food waste were halved?

The FAO has concluded that “roughly one-third of food produced for human consumption is lost or wasted globally.”[ii]   If we halted this loss or waste an extra two billion people could be fed.  If we halved loss and waste an extra one billion people could be fed. 

How many more people could be fed if EU consumers reduced food intake to recommended levels?

EU consumers generally have a higher food intake than recommended by nutrition experts.  Overconsumption is a form of food waste.

Eurostat data show that EU citizens consume 3,450 kcal each per day - 950 kcal more than is needed.[iii]  This means that the average EU citizen over-consumes 346,750 kcal per year.  As the average calorie need is about 1 million kcal each per year, the food that would be saved if the EU’s population of 500 million were to reduce calorie intake to recommended levels would feed around 170 million additional people. 

The UN estimates that world population will reach 9.3 billion by 2050, an increase of 2.3 billion on today’s figure.  Feeding the extra 2.3 billion people does not necessarily require a 60%-70% increase in food production.  The extra food needed could be made available by:

  • Halving the amount of cereals that, on a business-as-usual basis, would be used for animal feed by 2050; this would enable an extra 1.75 billion people to be fed
  • Halving food losses and waste; this would allow an extra one billion people to be fed
  • Reducing the food intake of those who over-consume.

The challenge of feeding nine billion does not primarily centre around increasing food production but on restructuring the way in which we use the food that we produce.


Peter Stevenson is Chief Policy Advisor, Compassion in World Farming.


[i] Nellemann, C., MacDevette, M., Manders, et al. (2009) The environmental food crisis – The environment’s role in averting future food crises. A UNEP rapid response assessment.  United Nations Environment Programme, GRID-Arendal,

[ii] Jenny Gustavsson Christel Cederberg Ulf Sonesson, et al. (2011) Global food losses and food waste: extent, causes and prevention, FAO, Rome ,

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