How much food do you throw out of your fridge each week?
All those leftovers, milk and lettuce that are left to spoil add up.
According to a new report by a London-based professional engineering institution, the world produces around four billion metric tonnes of food a year. But as much as 50 per cent of it winds up being wasted.
The report by the Institution of Mechanical Engineers blames ineffective harvesting and poor storage and transportation practices, as well as market and consumer behaviours for the staggering amount of food that never ends up being eaten.
With the United Nations expecting the world will need to feed 9.5 billion people by 2075, the report warns, "This level of wastage is a tragedy that cannot continue to succeed in the challenge of sustainably meeting our future food demands."
In newly developing countries, primarily in Africa and Southeast Asia, the bulk of the waste happens on farms or during storage and transportation at the start of the supply chain, the report says. But in developed countries, much of the food is wasted due to retail and consumer habits.
Every year, it says, 30 per cent of the United Kingdom's vegetable crop is never harvested because the vegetables do not meet supermarkets' criteria for what consumers expect. Carrots may be too crooked, cucumbers too small, and radishes not round enough.
But a significant amount of waste also occurs at home.
"Overall between 30 per cent and 50 per cent of what has been bought in developed countries is thrown away by the purchaser," the report says.
Food and personal finance websites offer plenty of advice on how to do one's part to reduce food waste, however.
The Kitchn suggests keeping a food waste diary to track how much you throw out to help you make the most of leftovers and create better shopping lists.
TLC Home offers ways of turning vegetable scraps, like squash seeds and trimmed carrot ends, into snacks and meals.
AOL's DailyFinance encourages people to plan what they need before shopping and to actually store and eat leftovers.
How much food do you think your household wastes?