Throwing out a pound of boneless beef effectively wastes 24 times more calories than throwing out a pound of vegetables or grains. Egg and dairy products fall somewhere between the two extremes. Morgan Walker/NPR hide caption

itoggle caption Morgan Walker/NPR

Europeans throw away 90 million tons of food each year, including these vegetables pulled from waste bins of an organic supermarket in Berlin. A new German website aims to connect surplus food with people who want it. Fabrizio Bensch/Reuters /Landov hide caption

itoggle caption Fabrizio Bensch/Reuters /Landov

The digester eggs at Newtown Creek Wastewater Treatment Plant in Brooklyn contain millions of gallons of black sludge. Courtesy of New York City Department of Environmental Protection hide caption

itoggle caption Courtesy of New York City Department of Environmental Protection

Roger Gordon (left) is offered a box of bananas from a worker who was throwing away the lightly speckled fruit at Mexican Fruits in Washington, D.C. Gordon's startup, Food Cowboy, works with truckers to divert edible produce from landfills to food charities. Serri Graslie/NPR hide caption

itoggle caption Serri Graslie/NPR

Tristram Stuart, founder of Feeding the 5000, is helping to organize several disco soup events across Europe for World Food Day. /Courtesy of Feeding the 5000 hide caption

itoggle caption /Courtesy of Feeding the 5000

Doug Rauch wants to take wholesome food that grocers have to throw away and cook and sell it as low-cost, prepared meals. Bunnyhero/Flickr hide caption

itoggle caption Bunnyhero/Flickr

At her bakery in Costa Mesa, Calif., Rachel Klemek sells cabernet brownies made with a flour substitute derived from grape pomace, a byproduct of winemaking packed with nutrients known as polyphenols. Mariana Dale/NPR hide caption

itoggle caption Mariana Dale/NPR

Compost bins at the Grand Army Plaza Greenmarket in Brooklyn, N.Y. are part of a pilot program to get New Yorkers to recycle their food waste. Courtesy of Grand Army Plaza Greenmarket hide caption

itoggle caption Courtesy of Grand Army Plaza Greenmarket

A worker dumps a bucket of tomatoes into a trailer in Florida City, Fla. Much of the lost and wasted weight in fruits and vegetables is water, according to a report by the World Resources Institute. Joe Raedle/Getty Images hide caption

itoggle caption Joe Raedle/Getty Images

Got spaghetti? Dogs digest starch more efficiently than their wolf ancestors, which may have been an important step during dog domestication. Lauren Solomon/iStockphoto.com/Nicholas Moore /Courtesy of Nature hide caption

itoggle caption Lauren Solomon/iStockphoto.com/Nicholas Moore /Courtesy of Nature

A 1,000-pound butter sculpture is unveiled at the 97th Pennsylvania Farm Show in Harrisburg last week. Bradley C. Bower/AP hide caption

itoggle caption Bradley C. Bower/AP

The Austrians behind Waste Cooking want to show the culinary possibilities of food that ends up in the trash. Courtesy Wastecooking.com hide caption

itoggle caption Courtesy Wastecooking.com

Charlotte Douglas International Airport has deployed an army of 1.9 million worms to eat through its organic waste. The airport has reduced the trash it sends to the landfill by 70 percent. Julie Rose hide caption

itoggle caption Julie Rose

Glen Osterberg (right) and another line cook at Lupa learn how to use the LeanPath waste tracking software. Eliza Barclay/NPR hide caption

itoggle caption Eliza Barclay/NPR

The National Restaurant Association says getting restaurants to focus on the food waste problem is a big challenge. Justin Sullivan/Getty Images hide caption

itoggle caption Justin Sullivan/Getty Images

Most of the gleaming steel tanks outside Fage's yogurt factory hold milk. One, however, holds the yogurt byproduct whey. Dan Charles/NPR hide caption

itoggle caption Dan Charles/NPR

Tim Opper, of Cabot Cheese, inspects equipment that separates whey protein from sugar in the company's whey processing plant. Dan Charles/NPR hide caption

itoggle caption Dan Charles/NPR