By SARAH LYALL

Published: October 18, 2006

ROTHERHAM, England � Five months after the celebrity chef Jamie Oliver succeeded in cajoling, threatening and shaming the British government into banning junk food from its school cafeterias, many schools are learning that you can lead a child to a healthy lunch, but you can抰 make him eat.

The fancy new menu at the RawmarshSchoolhere?

揑t抯 rubbish,� said Andreas Petrou, an 11th grader. Instead, en route to school recently, he was enjoying a north of Englandspecialty known as a chip butty: a French-fries-and-butter sandwich doused in vinegar.

揥e didn抰 get a choice,� he said of the school food. 揟hey just told us we were having it.�

The government抯 regulations, which took effect in September, have banished from school cafeterias the cheap, instantly gratifying meals that children love by default: the hamburgers, the French fries, the breaded, deep-fried processed meat, the sugary drinks.

Now schools have to provide at least two portions of fresh fruit and vegetables a day for each child, serve fish at least once a week, remove salt from lunchroom tables, limit fried foods to two servings a week and cut out candy, soda and potato chips altogether.

The rules apply to schools in Englandand Wales; Scotlandhas a separate healthy lunch program.

But weaning children who consider French fries a major food group is not easy. There is no nicotine patch equivalent for chicken nuggets.

And many parents object to being lectured by Londoners like Mr. Oliver, whose angry television show 揓amie抯 School Dinners� first alerted the nation to the horrors of school food like 揟urkey Twizzlers� � minuscule bits of meat processed with many nonmeat products, molded into shapes and deep-fried.

揘o matter how healthy it is, if kids don抰 like it they抮e not going to eat it,� said Julie Critchlow, a parent at Rawmarsh, a high school set between a sprawling housing project and the south Yorkshirehills. She mentioned the school抯 new low-fat pizza and tagliatelle and meatballs as being particularly unappetizing to her children and said the cooks were so overworked that the baked potatoes were being served half-cooked.

The fact that Rawmarsh now bans children who do not go home for lunch from leaving school has made things worse, she said, leading to an overcrowded cafeteria and the elimination of the old fast-food-down-theroad option.

揟hey shouldn抰 be allowed to tell the kids what to eat,� Mrs. Critchlow said of the school authorities. 揟hey抮e treating them like criminals.�

Mrs. Critchlow has become a notorious figure in Britain. In September she and another mother � alarmed, they said, because their children were going hungry � began selling contraband hamburgers, fries and sandwiches to as many as 50 students a day, passing the food through the school gates.

The mothers closed their business after they were vilified in the national news media as 搈eat pie mums.� Mrs. Critchlow now feeds her children lunch at home.

Shaken by the bad publicity, the school says that the two women represent a small minority and that most children are happy with the healthier menus, which include two hot choices every day � entrees like haddock provençal, beef curry and navarin of lamb � as well as baked potatoes for the unadventurous.

If the children really hate the food, Rawmarsh argues, they can bring brown-bag lunches.

揑 t doesn抰 happen overnight; it takes an effort,� said Sonia Sharp, a local government official, speaking of the campaign to win the children over. 揥e have the responsibility for ensuring the health of our children. We want to teach them how to make the right choices for themselves.�

The menu changes at Rawmarsh are being replicated across Britain, which, much like the United States, is grappling with the issue of how to regulate school food to improve children抯 health. Although Britons collectively are not yet as fat as Americans, they are the fattest people in Europe. If current trends continue, the British Medical Association says, by 2020 some 30 percent of boys and 40 percent of girls here will be clinically obese.