Considering that 1 in 9 people on earth do not have enough food for a healthy life as of 2014, food should be used wisely. However, roughly half of all food is wasted annually in the world.
According to a 2013 report by the Institution of Mechanical Engineers in London, 2 billion tons of food -- about half of all produced -- goes to waste in the world. Food wastage occurs in both developing and developed countries. Consumers in developed countries, such as the US, throw away around 30% to 50% of the perishable foods they have purchased. Food wastage also occurs at the farming, transportation and processing levels of food production. Wasting food also means the resources used to produce the food, such as land and water, are being wasted.
More about food and hunger:
This guess is off the top of my head, but more than half of the food wasted in the USA is probably due to FDA regulations!