In the past 20 years, childhood obesity rates have more than doubled in the U.S. One out of four Arkansas high school students is overweight, according to state House Speaker Herschel Cleveland, who sponsored the new law. According to the American Academy of Pediatricians, 15% of Americans between the ages of 6 and 19 are obese.

The reports also calls parents' attention to severely underweight pupils.

School districts in Pennsylvania, Florida, Massachusetts, Michigan and South Dakota have established programs similar to Arkansas' in the last several years.

Critics complain that grading students for fat will expose children to taunts and strain schools' limited resources, and question whether overweight students or their parents need schools to point out the problem. Critics also assert that the schools provide insufficient physical education and are prime purveyors of fattening junk food. School officials and legislators around the country have begun reacting to the latter criticism.

This fall, vending machines were banned in Arkansas elementary schools under the new childhood obesity law. New York and Los Angeles have prohibited sales of soda and candy in schools. California recently passed a law banning soft drink sales to elementary and junior high school students and requiring school board approval of other junk food vending contracts. Officials in Massachusetts, Pennsylvania, Texas and New York City are working on proposals to cut down on junk food in schools. Such efforts often encounter resistance because many school districts receive a share of vending-machine revenue.

During the next year, a new Arkansas child health advisory committee will review school lunch programs, nutrition education, physical education, and vending machine contracts to determine whether schools are encouraging healthy life-styles. A hefty 69% of Arkansas children do not participate in any physical education classes at school.

Illinois is the only state in the nation that requires physical education through high school, and local school districts are generally free to experiment with more nutritious foods. Students returning to Mundelein High School in Illinois this fall were welcomed with bananas, apples and sugar-free muffins. Sodas, chips and candy bars were replaced with water, juice, granola bars, fruits and nuts. Hamburgers, chicken patties and chicken nuggets are now baked instead of fried. Burgers cooked with Michigan cherries have been a popular item for more than three years in Bloomington, Ill. schools.

Veggie burgers are offered in District of Columbia schools, and in Massachusetts, state representative Peter J. Koutoujian has sponsored a bill to impose strict nutritional guidelines for foods offered in public schools in his state. The law would ban sales of all soft drinks in schools during school hours as well as candy bars and fried foods.