Leftover food is the single largest contributor of waste (by weight) in the United States, according to the U.S. Environmental Protection Agency. Americans throw away 96 billion pounds of food waste each year, from home and commercial establishments. What’s more, when food decomposes without oxygen it produces methane, a greenhouse gas 21 times more potent than carbon dioxide.

One way to reduce food waste is to ditch those hard-plastic cafeteria trays, an approach colleges and universities across the country are taking. In a student-run survey at the University of Vermont, college students reduced their daily food waste by 44% when cafeteria trays weren’t available. Other schools are doing the same: on Earth Day 2008, 300 college campuses served by the food-service company Sodexo went trayless and the company estimated that for every 1,000 trayless meals served, 200 gallons of water are saved by not washing the trays. “My students found that the benefits were trifold: the first is reduced energy, water and detergent consumption, the second is you’re wasting less food and the third, which we didn’t study, but are assuming, is that people are eating less,” explains Sylvia Geiger, EatingWell dietitian and adjunct professor at the University of Vermont.

If eco-consciousness isn’t at the forefront of your mind, consider dining trayless as an uncomplicated diet: with less room to carry food (you only have two hands!), chances are there’s less food to eat.