The following article is from a slightly unusual source – the Institution of Mechanical Engineers in the UK. A slightly technical view, but well worth the read, specially if you are interested in FoodTech.
Today, we produce about four billion metric tonnes of food per annum. Yet due to poor practices in harvesting, storage and transportation, as well as market and consumer wastage, it is estimated that 30–50% (or 1.2–2 billion tonnes) of all food produced never reaches a human stomach. Furthermore, this figure does not reflect the fact that large amounts of land, energy, fertilisers and water have also been lost in the production of foodstuffs which simply end up as waste. This level of wastage is a tragedy that cannot continue if we are to succeed in the challenge of sustainably meeting our future food demands.
Original source: http://www.imeche.org/knowledge/themes/environment/global-food
Global Food Report (PDF): http://www.imeche.org/docs/default-source/reports/Global_Food_Report.pdf