The major source of North America's massive food waste is easily-remedied home everyday behavior -- a family of four loses up to $2,000 per year to discarded food.

Last week, I went on vacation. Before leaving, I tried to stretch out my cooking so that I ran out of groceries on exactly the morning of my trip. Anyone who's tried doing the same knows there's something deeply satisfying about that. 

One reason cleaning out your fridge feels like such an accomplishment is that it's actually very hard to do. New research by the Natural Resources Defense Council shows that 40 percent of the country's food supply gets wasted. At every step along the supply chain, some amount of food is being redirected away from its intended destination (someone's stomach), but by far the most significant point of waste is at the consumer level. We spend a stunning amount on items that don't make it to our mouths. A family of four can lose more than $2,000 per year in uneaten food. Here's a breakdown of food waste across the levels from farm to mouth:

NRDC

What are we doing with all that if we aren't eating it? About two-thirds of consumer food waste is due to spoilage, according to a recent survey of British citizens. Cooking too much food was largely responsible for the remaining third. In the United States, households toss out roughly a quarter of all the food they buy.

The proportions are mostly flipped when it comes to dining out. Restaurants have an economic interest in minimizing spoilage, so they've evolved very sophisticated ways of predicting how much they'll need to buy. But they can't speak to how much an individual diner is liable to eat at a meal, which is why on average, 17 percent of meals are left on the table. Inexplicably, more than half of these "potential leftovers" aren't boxed up; they're just thrown out.

The report suggests some ways to limit food waste, particularly at home, including being wary of buying in bulk, freezing an saving whatever you can, and finding creative ways to use aging food. In recipes, that is.  

In a country where overeating is basically a national pastime, the fact that the United States grows more than its citizens can eat, drink, or trade away is remarkable. But it's heartening to see how much of the waste can be avoided with some simple conscientious behavior and adjustments to routines.