It had to happen: slapping the greedy hand reaching out to sup at the trough of plenty. This CNN report details a new way colleges around the country are cutting down on food and water waste, while at the same time helping keep students hungry.

It's a simple idea really: Stop stocking college food halls with the common food tray. Colleges around the country have excised the trays from their larders and are seeing some pretty green results.

Two nationwide surveys conducted by Aramark, the country's largest university and college food servicer, found a 25-30% reduction in food waste per person when trays were not available. Makes sense -- especially when your eyes are bigger than your stomach during the lunch hour. Basically this means making students eat only what they can carry. You can imagine the cost savings for university and college food service providers.

And you can imagine the grumblings of hungry college students. Maybe they haven't learned about "going back for seconds" yet.

You know that old dieter's trick of putting your food on a smaller plate? The food looks bigger and you eat less. Colleges around the country are trying out a modified version of the plan by getting rid of cafeteria trays. Kids are taking less food and throwing out less food. And nobody has to stock and wash all those trays. Aramark, which runs cafeterias at 500 campuses, says removing trays cuts food waste by 25 to 30%.

The cafeteria giant thinks half of its customers will get rid of trays. They've done a white paper on schools that have tried to go trayless. Every time you use a tray someone back in the kitchen uses one-third to one-half gallon of water to clean it. Trayless eaters waste 1.2 to 1.8 ounces less food per meal, or somewhere in the neighborhood of 50 pounds a year. Food waste isn't defined in the paper, but I assume it means just what you throw out after the meal. The University of Maine at Farmington removed trays in February, 2007 and thinks they've saved $57,000 since then.

It's unclear, though, whether the schools are saving the money or Aramark is. Perhaps a mixture of both since the school would be the one supplying water and power. The study doesn't go into if going trayless actually cuts overall food consumption. That could offer some real health benefits. And it could mean that Aramark's costs come down significantly (or at least lessened the impact of rising food costs). The company has done some great work pointing out how accepting this simple inconvenience can save food, water, time and energy. I just hope the colleges will get to share in that bounty.