The more scientists study the issue of food waste - and its worrying implications for both the environment and global food security - the clearer it becomes how much of a problem it is.
Now, new research is giving us a few more reasons to clean our plates.
A study just out in the journal Environmental Science and Technology concludes that we're already producing way more food than the world actually needs - but a lot of it is being wasted, instead of used to feed people who need it.
That's a big problem for global food security as well as for the climate, given the huge amounts of greenhouse gases that go into producing the extra food - and the study suggests that the problem will only get worse in the future.
Scientists are already aware of how bad food waste is for the environment. The UN's Food and Agriculture Organisation reported that, in 2007, the emissions required to produce all the food that went to waste in the world amounted to at least 3.3 billion tons of carbon dioxide equivalent, more than most countries emitted.
The researchers used UN data to calculate the difference between the amount of food available in each country and the amount its citizens require in order to be healthy. For each country, there was either more food available than was needed to supply the nation's requirements - a food surplus - or not enough.
The researchers considered food surplus to be equivalent to food waste, as it represents food that was not needed but produced anyway. Presumably, the majority of a food surplus is wasted, although the researchers noted in the paper that some of it is likely used for animal feed or is consumed by humans through overeating.
The study found that the global food surplus increased overall between 1965 and 2010 from 310 extra kilocalories per person per day to 510 extra kilocalories, with the greatest surplus growth rates generally observed in developed nations. As of 2010, 20 per cent more food was being produced worldwide than was actually needed to feed the world's population, and overall the researchers estimated that the global surplus could be used to feed an extra 1.4 billion people.
The UN estimates that about 800 million people worldwide suffer from undernourishment, meaning there's currently enough wasted food in the world to solve the world's hunger problem nearly twice over - it just isn't reaching the people who need it.
The study highlights several important problems in the current global food system. First, the finding that there's more food than necessary in the world, while undernourishment still remains a global problem, implies that there are serious failings in the distribution of food worldwide.
"So much of poverty and famine aren't about a lack of resources overall - they're just distributional [problems]," said Emily Broad Leib, an assistant clinical professor of law and director of the Harvard Food Law and Policy Clinic. "It's not surprising to see that, and both across countries and within countries this challenge of the food markets really being attainable for certain segments of the population and not for others."
Read the full article here.