Sir

The existence of malnourished and hungry people has been used repeatedly in this journal and elsewhere as a justification for biotechnology and for the production of more food1,2. This assumption supports a main policy plank of the Rockefeller Foundation food biotechnology programme2 and other major international and charitable institutions.

Yet there are good reasons to be sceptical of the equation “more food equals less hunger”.

The world produces more than enough food at present to feed everyone, but nevertheless many people still starve or are malnourished1,2,3. As economist and Nobel laureate Amartya Sen has pointed out, it is poverty, not a physical shortage of food, that is the primary cause of hunger in the modern world4.

The political and economic reasons don't change: the amount of food that Ireland, for example, exported to Britain during the potato famine of 1845–46 would have been sufficient to feed those who starved. The root cause of the 1974 Bangladesh famine was a flood that displaced people from their jobs; more food was produced that year in Bangladesh than in surrounding years, yet — unable to earn money to buy it — up to 1.5 million people starved to death4.

Partial solutions such as local production of food, as suggested by Conway and Toenniessen2, cannot circumvent economic reality. Even the World Bank has concluded that the problem of hunger can only be solved by “redistributing purchasing power” to the hungry5.

What about the state of food supplies in, say, 2040, when it is predicted that there will be ten billion people compared with today's six billion? In absolute terms, the world already produces enough food to feed ten billion people — it's just that most of it is fed to animals (this accounts for 80% of all arable crops in the United States, a figure close to the world average6). If the area of arable land devoted to crops for human consumption were doubled to 40%, this need not drastically affect supplies of meat or dairy produce, since farm animals also eat other, non-crop foods such as grass in the summer, silage and hay in the winter.

Clearly, what is missing is the “purchasing power” of the poor.