BOSTON — Harvard is the world's richest university, yet it recently pulled whole grain pasta from the dining service menu, replaced cherry tomatoes with wedges and even started using more chicken thighs in lieu of breasts.

Harvard junior Daniel Demetri was outraged when he noticed the changes.

"It was like, who are they kidding?" he said.

Actually, the university with the roughly $35 billion endowment was just doing what many other schools are doing in these tight times. The nation's rising food costs are stirring up problems for dining halls, cafeterias and public school systems, and institutions serving thousands of people a day are trying to find ways to cut costs while maintaining quality.

At Harvard, it didn't last. In the face of outraged students demanding their whole grains it restored most of the items. But other places have stuck with the changes, or found more affordable ways to feed students.

Several schools have eliminated trays, on the theory that students will grab less if they have to carry the food in their hands. Still other schools, which charge students by the item, are increasing the cost of healthier choices.

Food prices rose more than 4 percent in the United States last year, the biggest jump since 1990, according to the U.S. Department of Agriculture. A similar increase is predicted this year.

Food costs globally are being driven up by a variety of factors, including the rising price of petroleum products, used not just for transportation, but for fertilizers and processing. Grain prices are increasing as they are used to produce biofuels and to feed livestock to satisfy a growing demand for meat in developing countries.

Dealing with food price spikes is made more difficult by the fact schools generally set their dining hall budgets well before the start of the school year.

"We don't want to compromise quality, and we're not going to compromise nutrition," said Scott Berlin, director of dining and hospitality services at the University of California, Santa Cruz, which experimented briefly with going trayless.

San Diego State University also has done away with trays at its dining room in the Cuicacalli resident hall, a traditional "all-you-care-to-eat" facility. The move, started in September, saved the facility 4.2 percent on food costs, said Paul Melchior, director of dining services, and actually allowed an expansion of the menu.

In addition, no trays mean less washing, cutting energy and soap costs. Stephanie Savoian, a sophomore accounting major at San Diego State, ate at the facility before it went trayless.

"People would tend to grab as much stuff as they could so they didn't have to go up again, and I know from experience people would waste a lot of food that way," she said.

The University of Massachusetts in Amherst, which has the third largest on-campus dining operation in the country, serving 40,000 meals per day to 13,600 students, has instituted a "small plate/big flavor" program, said Ken Toong, executive director of dining services.

Instead of a 6-ounce piece of chicken, students now get 4 ounces. Instead of 4-ounce bagels, students now get 3-ounce bagels. Students are welcome to get seconds if they are still hungry, Toong said, but the smaller portions of higher quality food has reduced waste.

Higher food prices are not just a problem for colleges.

School systems that operate their own dining services are also looking at ways to save, said Jean Saunders, wellness director at the Chicago-based Healthy Schools Campaign.

Schools must meet federal government minimum nutrition standards, so changing menus is often not an option, she said. Instead, many school food service operations are trying to boost revenue with increased sales of supplemental items, including juices, energy bars and other snacks.

She also expects many school systems to look hard at their contracts this summer and try to negotiate better deals for the new school year.

Schools are going to have to become more creative at saving money as food prices continue to rise, said UC Santa Cruz's Berlin. "This is a hot topic throughout the hospitality industry that's not going to go away," he said.