Food waste or food loss is food that is discarded or cannot be used. The causes of food waste or loss are numerous, and occur at the stages of production, processing, retailing and consumption.
As of 2013, half of all food is wasted worldwide, according to the British Institution of Mechanical Engineers (IME).Loss and wastage occurs at all stages of the food supply chain or value chain. In low-income countries, most loss occurs during production, while in developed countries much food – about 100 kilograms (220 lb) per person per year – is wasted at the consumption stage
The 2011 SIK study estimated the total of global food loss and waste to around one third of the edible parts of food produced for human consumption, amounting to about 1.3 billion tons per year. As the following table shows, industrialized and developing countries differ substantially. In the latter, more than 40% of losses occur at the postharvest and processing stages, while in the former, more than 40% of losses occur at the retail and consumer levels. The total food waste by consumers in industrialized countries (222 million tons) is almost equal to the entire food production in sub-Saharan Africa (230 million tons).