America's schoolchildren will eat healthier lunches if schools lock up the candy and soda machines and put more fruits and vegetables - and fewer fatty foods - on the cafeteria menu, a panel of experts said.

The unofficial Citizens Commission on School Nutrition also urged a sharp increase in funding for the school lunch program, which feeds about 24 million children a day.In addition, the commission called for efforts over several years to limit the fat content in those foods to a level accounting for no more than 30 percent of the calories in a school lunch.

Many health authorities, as well as the new edition of the government's Dietary Guidelines for Americans, recommend a 30 percent ceiling on fat. A recent federal study indicated fat accounts for 37 percent of the calories consumed by children.

Congress appropriated $3.38 billion for the school lunch program this fiscal year. The program provides free or reduced-cost meals to low-income children.

The commission, sponsored by the Center for Science in the Public Interest, unveiled its recommendations this week. Unlike calls for reform from other consumer groups, it came with support from the school lunch industry.

"We are delighted to lend our support to and endorse the . . . publication" of the recommendations, said Vivian Pilant, a leader in the American School Food Service Association. "It is important to note this report establishes flexible goals and recommendations for the national school lunch program."

As an example, the recommendations called for reaching, over the next two to four years, a 35 percent limit on calories from fat, averaged over a month. Schools would aim for a 30 percent limit by the end of this decade.

The report suggested the government could help by adopting rules that set nutritional standards for lunches, allowing only low-fat milk to be sold and helping to train cafeteria workers and students about healthful foods.

One of the four major suggestions by the panel was for a ban on the sale of candy, soda, fried chips, sodas and other relatively non-nutritious foods on school property during school hours. Some schools use the sales as a way to raise money for special projects.

The experts said a switch to higher-fiber and lower-fat meals should be accompanied by explanations to students about what is best to eat.