WASHINGTON — Redheaded birthday boy Jake Balcom, newly 11, walked into the principal's office at Centennial Lane Elementary School in Ellicott City, Md., 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 country to take the battle against childhood obesity to one of education's most beloved functions: the school party.

But some worry 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 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," she 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.

Some, however, think 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 while 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 was not too bothered by their absence because he had celebrated his birthday with his friends.

They went to see the movie "Wallace & Gromit: The Curse of the Were-Rabbit" and hung out on his front porch — where they feasted on sloppy Joes and birthday cake.