Photo: VirtualErnThe answer is:
People buy less food and subsequently eat less and throw away less. For the customer, it’s good for the budget and the waistline; for the cafeteria (and the environment), it substantially cuts down on waste. Sounds like a win-win situation, unless you are the party who profits most from selling a high volume of food. Here, from an article in Restaurants and Institutions, are some details:
Foodservice managers find that when trays are eliminated from all-you-can-eat dining halls, diners take less food and therefore waste less. In a study released this summer, Philadelphia-based Aramark Higher Education reported that schools saw a 25 percent to 30 percent drop in food waste per person when trays were removed.
In addition, the move cuts back on overhead, because there are no purchase or ongoing replacement costs for trays, says Tom Post, president of campus dining for Gaithersburg, Md.-based Sodexo, which manages foodservice programs on more than 600 campuses. Many Sodexo campus accounts already have retired their trays.
Hat tip goes to Josh Friedland, who blogged about this at The Food Section. For further reading, see earlier posts on the Dutch university cafeteria that’s set up as a behavioral lab and the notion of whether a rise in plumbing facilities encourages a rise in food consumption.
I also wonder if trayless cafeterias might see a spike in shoplifting. It might begin accidentally. Since roughly 83 percent* of college undergrads wear sweat pants to breakfast, I can see them using a big, baggy pocket to hold the orange juice or breakfast burrito that they can’t comfortably carry, only to discover they’ve gone past the checkout without paying for it, thus realizing how easy it would be to do it again and again. This would of course be hard to do with scrambled eggs or a salad.
*Made-up statistic.

You forget that college cafterias are typically all you can eat and therefore you don’t have to pay for what you get. I’m guessing that making students actually pay for their meals would lead to even less waste.
Can’t we just make the trays smaller?
83% seems low.
I think the most notable savings would be to those college cafaterias that offer all you can eat services. I know when i was in college i loaded up my tray with as much as possible, just so that I didnt have to walk back to the end of the line to get more food. kids lazyness add to the problem and who knows, maybe waist sizes will drop in the US if kids have to keep getting out of their chair to go get more food.
I think its a great idea. Save more, spend less, and get some fat kids walking to get their next meal in the hopes of burning a calorie or two.
Apparently Paul Franceus hasn’t been on many college tours… At the campuses I’ve been to in recent years, all you can eat is the is the exception, not the rule these days.
As someone who goes to a college that just eliminated trays, it really isn’t a win-win situation. It might make people eat less food and waste less, but it substantially increases the hassle when you have to carry a plate or two plus a drink and silverware. All that isn’t easy to carry without a tray.
I imagine the vast majority of cases where food service providers go trayless are in buffet-style cafeterias, not pay-per-item snack bars. Honest people tend not to take more than they will eat when they are actually paying for each item, which for most people works out to be less food than they are able to carry. No need to stuff a breakfast burrito in a cargo pocket. I suspect the theft rate from a la carte campus eateries would be the same with or without trays.
Several all-you-can-eat Korean BBQ buffets that I have visited have an ingenious method of cutting down on waste: a tax on uneaten food. There are prominent signs claiming that uneaten food will incur a penalty of $X per pound. I’ve never seen this penalty actually applied, but I do find myself only taking what I can eat.