A widely quoted figure of one third of all food available for human consumption lost or wasted is made up of both food lost before it reaches the consumer and food wasted once it arrives in the kitchen.
Reducing food waste is a key challenge in fighting climate change; wasted and lost food accounts for almost 10% of all our greenhouse gas emissions, according to the UN.
Common estimates for global food waste are too low. The FAO estimated food waste to be 214 calories per day per person in the world in 2015 (214 kilocalories/day/capita - a kilocalorie is another word for what's commonly called a calorie). Dutch research, using data from the FAO, World Bank and World Health Organization (WHO) and published in 2020 in the journal, Plos One, suggests every person in the world is wasting over 500 calories of food a day (not including food lost in the production process before it gets to the consumer). Food waste is more of a problem in richer countries; and started to rise above a daily income of about seven dollars per day.
In 1998, the Brazilian Ministry of Agriculture estimated that around 14 million tonnes of food are wasted annually in Brazil. In financial terms this is around US$ 4 billion per annum in fruit, greens, vegetables and other perishable food. Specifically 10-15% of oranges are wasted; 30% of vegetables and peppers; 30% of grains; 21% of rice; 25% of chicken; 15.8% of tubers and 75% of milk. Another 20% of corn, soy beans and other beans are spoilt due to errors in the operation of agricultural machinery; the grains rot in warehouses due to excessive humidity and because they are stored in sacks and other unsuitable packaging. Contributing to food wastage are: householders throw out 20% of certain foods, such as skins and leaves with high nutritional value; restaurant customers leave 20% of the food they order; badly-planned packaging accounts for 30% of road transport insurance claims for damaged food; the retail trade buys more food than needed, taking into account losses in stocking and exhibition of produce. In the case of bananas, the retailer offers 1.66 kg for each kilo sold which, added to the 20% lost in production accounts for a wastage of almost 60%; the same happens with avocados, tomatoes and papayas, with an estimated wastage of 40% in the total amount of fruit produced in Brazil.