Global food waste stands at 2.8 trillion pounds a year -- created by farmers, supermarkets and humans alike -- all along the food chain, according to an article this month in National Geographic.

In the U.S. more than 30 percent of the food isn't eaten, Elizabeth Royte said, author of "The High Cost Of Food Waste."

"I was trying to shrink my garbage footprint, and so I started composting my food, and I learned about the vast quantities of food that go into landfills and my take on it from an environmental perspective. When we bury food in landfills it generates methane, which is a very potent greenhouse gas," Royte told Latin Post.

"But as I learned more I realized the economics of this, and it is tied into hunger. And most of this food is good and beautiful. It is not eaten because the supermarkets are culling and they are competitive with each other and take healthy, nutritious and pretty good looking food off the shelf because sometimes a zucchini is too curvy or a cucumber or a banana doesn't have enough life left in it and so it goes into a dumpster."

That routine behavior at supermarkets contributes to a third of our food being wasted, at a value of $162 billion annually or 133 billions pound of edible food. If you pile all that food on a football field, it would be five miles high. It would fill 100 Empire State buildings each year. While this does seem shocking and wasteful, she said this represents an opportunity. There are 49 million Americas who are food insecure, which means they don't always know where their next meal is coming from. Though they might receive government subsidies through food stamps and other benefits, the amount comes to $1.20 a meal. Royte said there are systems in place for farms to distribute to food banks and gleaning groups -- Scouts groups, church groups -- who organize to pick up produce to get it to the people most in need.

Royte thinks we are wasteful because food is cheap. We only spend about 10 percent of our income on food in the U.S. It is also abundant, and we pay no price for putting it in the trash. 

One of the problems is both supermarkets and consumers tend to throw away produce that is perfectly nutritious but has passed it "sell by" or "best by" dates. The Natural Resource Defense Council is urging the U.S. government to standardize the confusing terms. Scholars and academics are trying to influence home economics classes in schools to teach young people to embrace oddly-shaped produce, learn how to store food properly, savor leftovers and compost what remains.