BERMUDA DUNES, Calif. -

The average student stresses about pop quizzes and grades on his or her next report card. Now, some worry about a different kind of scholastic measurement: their body mass index.

Elementary schools in 19 states, including California, are testing students' body mass index, or BMI. Those measurements are then sent home to parents as reports, noting whether or not the child is considered overweight. A San Fernando Valley preschool also participated.

Kids have started calling them "fat letters."

"I'd be upset. It would hurt my feelings if it said my kids was too fat. It's not their business," said Sarah Dunlap, of Indio.

Nissa Alejos, of La Quinta, said, "I'd probably just laugh at it. I don't think it's their business."

According to the Centers for Disease Control and Prevention, more than one-third of children and adolescents are considered overweight or obese. With skyrocketing numbers, could the letters help?

"I do think they could be useful in the sense to inform parents that we have a national issue, the issue of obesity," said Stephen Wright, physician assistant certified in pediatrics at Desert Oasis Healthcare in Bermuda Dunes.

Desert Sands Unified School District assistant superintendent Sherri Johnstone said the district does not send home the so-called fat letters, but rather focuses on promoting healthy eating and living. It only sends home results from a series of student physical fitness tests.

Palm Springs Unified School District spokesperson Joan Boiko said BMI measurements are not part of its standard practice but are rather done only for special-requested health assessments.

Wright said it takes a team effort to prevent health issues and get kids the nutritional help they need.

"If the school can identify those people without singling them out and we can accomplish weight reduction, if it can be done as a team, the better," said Wright.

Some parents worry the so-called fat letters will stir up bullying by peers or cause more emotional problems.

"Them telling kids they're too fat or skinny, that lowers self-esteem," said Dunlap.