Redheaded birthday boy Jake Balcom, newly 11, walked into the principal's office at Centennial Lane Elementary School in Ellicott City ready for his big surprise. His name had been announced over the loudspeaker moments earlier. Today was going to be special.

Back in the day -- like, before fifth grade -- Jake's parents would bring cupcakes to school in his honor. But this year, for the first time, his Howard County school has forbidden parents from bringing "edible treats" for students' birthdays. That means no more cupcakes, brownies, chocolate chip cookies, cake, ice cream, Rice Krispies treats or pizza.

Instead, Jake got a handshake from Principal Robert Bruce. And a colorful pencil and card.

"We hope that you have a terrific birthday," the card read.

Jake just smiled. And went back to class.

Centennial Lane is part of a movement across the Washington area and the country to take the battle against childhood obesity to one of education's most beloved functions: the school party. But some are worried that the fight is going one step too far -- and taking some of the fun out of being a kid.

Schools, where many children eat two of their day's meals, are being pushed to the front lines of the battle against kiddie bulge. A federal law requires schools to create wellness policies that encourage students to be more active and eat more healthfully. Some schools in Virginia have started exercise clubs. In Maryland, schools are cracking down on vending-machine junk food.

Now, there is a focus on school parties, said Margo Wootan, a policy director at the Center for Science in the Public Interest, a Washington-based nutrition advocacy group. The birthday party, the Halloween party, the Valentine's Day party, the end-of-the-year party -- all are centered on junk food, according to the advocacy group.

"There is this good-food movement sweeping the country where schools are really looking at their policies in new ways and bringing them in line with concerns about childhood obesity and children's poor diets," she said.

Wootan's daughter is a second-grader at Janney Elementary in Northwest Washington. Wootan said some celebrations at the school have gotten out of hand. Last year, for example, one mother brought pizza and Cheetos for lunch, plus cupcakes and ice cream for snacks, for her child's birthday.

"Parties are no longer a special treat for kids. Parties happen all the time," Wootan said. "And each party has just escalated to the point where the amount of junk food at just one party has really gone overboard."

Administrators usually plan at least two school parties -- one before winter holidays and one at the end of the school year. But on top of that are several holidays, numerous birthdays and any number of other occasions for celebration.

Tomorrow, it's Halloween. At Centennial Lane, each class can have only one "cupcake item" and one "candy item" for this year's Halloween party, the principal said. He noted that the policy also is designed to protect students who have food allergies: Twenty-six students have EpiPens, used to treat severe reactions, at the school health office -- just in case.

"We're looking for a better balance than there's ever been," he said. "We want the students to certainly have fun."

At Burning Tree Elementary School in Bethesda, Principal Helen Chaset said that the school takes a more liberal approach to birthday celebrations but that some classes combine students' birthday parties into one celebration a month. Last year, Louise Archer Elementary School in Vienna replaced its Friday pizza parties with "reward walks."

According to the Centers for Disease Control and Prevention, the proportion of overweight children ages 6 to 11 has skyrocketed in recent decades, from 7 percent in 1980 to 16 percent in 2002. Among 12- to 19-year-olds, the rate of obesity more than tripled, from 5 percent to 16 percent. Health officials have called obesity a pandemic.

Joyce Cimbalista, a parent at Cedar Lane Elementary School in Ashburn, said she has taken the initiative at her school.

Last year, during a party for third-graders, Cimbalista and several other parents brought fruit in addition to the traditional muffins and doughnuts the school had requested. The children ate a watermelon, she said, as well as grapes, cantaloupe and bananas.

"I personally am tired of all the sweets in the schools," Cimbalista said. "Each person that hands out a treat doesn't realize how many treats [children] get in one week."

Diane Mikulis celebrated her son's birthday last year at Triadelphia Ridge Elementary School in Ellicott City with carrots and dip and apple slices with caramel. The school's health policy "discourages" cakes and cupcakes.

"It's a little bit of a treat," Mikulis, who serves on the Howard school board, said of her healthful alternative. "Some parents would really go overboard."

Some, however, say that well-meaning efforts to raise healthier children are turning into draconian mandates.

"Getting rid of birthday treats is absolutely absurd," said Dan Mindus, senior analyst for the Center for Consumer Freedom, an advocacy group funded by the food industry.

"The occasional treat is not going to cause what has been termed an obesity epidemic. . . . This is a hysterical response to a legitimate problem," Mindus said.

Susan Combs, agricultural commissioner of Texas, last year implemented rules banning junk food in schools and forbidding elementary-age students from sharing unhealthful snacks from home with other students, effectively putting the kibosh on school birthday parties.

But a backlash was so strong that Combs soon issued a clarification that allowed students to bring cupcakes and other sweet treats for their classes on their birthdays. Texas legislators drove the point home by unanimously passing a bill, dubbed the "cupcake amendment," which ensured that baked goods remained legal.

At Centennial Lane, the principal said some parents have complained about the school's new policy, and others have adapted by bringing in nonfood treats -- such as rulers or erasers.

"They're only children once. I can certainly relate to that," Bruce said. "But it's really bigger than cupcakes for birthdays."

Jake Balcom said he misses bringing treats to school. But he wasn't too bothered by their absence because he had celebrated his birthday with friends. They went to see the movie "Wallace & Gromit: The Curse of the Were-Rabbit" and hung out on his porch -- where they feasted on sloppy Joes and birthday cake.

For their birthdays, Austin Johnson, 8, left, and Jake Balcom, 11, receive pencils and cards from Principal Robert Bruce at Centennial Lane Elementary School in Ellicott City.Austin Johnson holds gifts from Centennial Lane Elementary School Principal Robert Bruce. "It's really bigger than cupcakes for birthdays," Bruce says.