As students increased their water intake, teachers noticed fewer students reporting headaches. Discipline problems also dropped, and students appeared more attentive than when they ate sugary snacks all day.

The deal, brokered the William J. Clinton Foundation, expels all soda from elementary and middle schools and allows only diet sodas to be sold at high schools. It also caps the number of calories per drink at 100, and it limits portion sizes.

It comes a year after legislators in 40 states considered more than 200 bills targeting junk food and soda sold in the nation's schools. Those sales rake in tens of thousands of dollars in school funding, which is spent on everything from athletic department supplies to school field trips.

Getting those foods -- and their funds -- out of classes is a sticky ordeal.

Noticeable Changes in Students

Tom Scullen, superintendent of the Appleton Area School District in Wisconsin, said he was pleased at the new soft drink deal, but it "was not the attitude of the pop industry a year ago."

The Appleton district met stiff resistance from the industry three years ago, when it banned all soda sales at its schools. One company "went so far as to bring in a nutritionist to extol the virtues of pop," Scullen said. "It was hard not to laugh at them."

Now, Appleton students carry water bottles to class and buy 100 percent fruit juice and low-fat milk from the vending machines. The district had expected its three high schools to lose $20,000 a year in funding from vending contracts but broke even after students began buying the healthy snacks, Scullen said.

As students increased their water intake, teachers noticed fewer students reporting headaches, Scullen said. Discipline problems also dropped, and students appear more attentive than when they ate sugary snacks all day, he said. The district and Lawrence University in Appleton are doing research into the connections between the healthier foods students now eat and the changes educators have noticed.

Such attempts have gotten the attention of lawmakers, who have made schools a hotbed in the nation's debate over childhood obesity.

Double Standard

"That's where children spend many of their waking hours," said Margo Wootan, director of nutrition policy at the Center for Science in the Public Interest. "Parents aren't there to guide their choices, and there's a lot of soda and junk food in schools. It just doesn't make sense to sell anymore."

California, Maine and New Jersey have limited or eliminated such sales, and Congress is weighing a bill that would require that currently unregulated food sold in student stores, vending machines and a la carte lines meet national nutritional standards. In Wisconsin, state Rep. Chuck Benedict (D-Beloit) introduced a bill this year that would have allowed only diet sodas to be sold in schools, but the measure stalled in committee.

But such laws can be a tough sell.

The soft drink industry rallied against a Connecticut law that banned sales of both soda and sports drinks in schools, Wootan said. Legislators said to expect "hand-to-hand combat" over the measure, which narrowly passed last month.

In Illinois last month, legislators blocked the state Board of Education's move to eliminate junk food and soda in schools.

Colorado's governor vetoed a bill that would have required half of school vending-machine choices to meet some nutritional standards partly because he said students visiting the Capitol might note legislators imposing tougher restrictions on students than themselves. Vending machines at the state Capitol offer chips, candy bars, cookies, pastries, crackers and nuts, he said in a statement.

Those foods also are abundant in schools.

In the Northern Ozaukee School District, officials next school year will remove a Little Debbie cart from the lunchroom, as the district steps up efforts to encourage healthy student eating. The changes result from a federal rule requiring districts that participate in the National School Lunch Program -- 98 percent of public and private schools in the state -- to enact policies on wellness and nutrition the start of next school year.

The new soda agreement "may just help us get more quickly where we'd like to be, anyway," Superintendent William Harbron said.

"There's always that motivation that someone says here is what you need to do," Harbron said. "Then you're more likely to get it done. And it's the right thing to do."

Students May Bring Their Own

The number of unhealthy options has increased in recent years -- 99 percent of high schools, 97 percent of middle schools and 83 percent of elementary schools sell food in vending machines, school stores or a la carte lines, according to a report the Government Accountability Office.

But students said the new agreement probably won't change the appetite for sugary food and could prompt students to bring it themselves.

Crystal Lipek, a senior at the Milwaukee High School of the Arts in Wisconsin, said many students already bring their own drinks -- ranging from bottled water to soda -- and more will do so if soda isn't stocked in vending machines.

"If we didn't have that [in vending machines], I don't think anyone would get up in arms," Lipek said.

That's the same reaction as Rosemary Andino, a junior at Milwaukee's South Division High School. Andino said students will have plenty of access to soft drinks on their way to school.

"There's a gas station over there, there's a store over there," she said. "Or else we're probably going to drink more when we get home because we didn't have it all day."

Only Diet in High Schools

Under the agreement with Cadbury Schweppes, Coca-Cola, PepsiCo and the American Beverage Association, the companies will sell only water, unsweetened juice and low-fat milks in elementary and middle schools. Diet sodas would be available only in high schools. The deal also would limit portion sizes, to 8-ounce drinks at elementary schools, 10 ounces at middle schools and 12 ounces for high schools.

Diana Garza, a spokeswoman for the Atlanta-based Coca-Cola Co., said "these voluntary guidelines escalate ... the shift to lower calorie, more nutritious beverages."

But the agreement won't take effect for several years, and critics questioned the enforceability of the group's promise to implement changes at 75 percent of the country's schools the 2008-'09 school year.

Some also said the industry isn't making enough concessions because most elementary schools already prohibit soda sales and middle school sales are minimal.

Enforceability in Doubt

The bulk of vending sales occurs at high schools, and the agreement allows companies to continue selling sports drinks, which also have come under fire for their high sugar content.

Gary Ruskin, executive director of the non-profit consumer group Commercial Alert, said he'd like to see Congress enact a law to hold the industry accountable to its promise.

"If there were a law, then the law would be enforceable," Ruskin said. "But it doesn't appear there's any enforceability here.... The agreement itself might not be worth the paper it's printed on."

In Milwaukee Public Schools, officials said the deal would likely only prompt one change -- swapping 16-ounce drinks at high schools for 12-ounce ones. MPS already forbids schools from operating vending machines during lunch hours, but Michelle Nate, chief of finance and operations for the district, said it will have to step up enforcement of healthy choices after its new nutrition policy goes into effect.

Right now, that's left to individual schools, which use proceeds from all sales for athletic and activity funds, among other things.

"I think everyone is focused on the importance of nutrition and decreasing the incidence of childhood obesity," said Sandy Procopio, another of the district's supervising dieticians. "But I think we're in for a bit of a battle."