A New York City third-grader was sent home from school with a note declaring she is "overweight," the New York Post reported.

At 66 pounds, 9-year-old Gwendolyn Williams is unhealthy according to the weight range the city's Department of Education follows to classify girls her age. Titled "Fitnessgrams," the letter said because Williams' Body Mass Index is 19, she falls "outside of a healthy weight," according to the letter obtained by the NY Post.

"I'm 4-foot-1, and 66 pounds, and I'm like what?!" the P.S. 29 student told the newspaper after she received the letter.

"I just don't think that it's fair to be called overweight when you're not really overweight," the Staten Island girl said.

All students in the city's public school system received the Fitnessgram, which carry the results of their weight and height that was measured last November.

Williams' mother complained to the school's principle about the letter, who told her that students were not supposed to open them.

"My response is, they're kids. How can you believe they're not going to open it?" Laura Bruij Williams told the NY Post.

The DOE supported the Fitnessgrams, saying they are "just one indicator...which helps students develop personal goals for lifelong health," a spokeswoman told the newspaper.

But experts say the BMI reports can inflict damage to a child's self-esteem.

Chevese Turner, from the Binge Eating Disorder Association, told the NY Post that BMI was created years ago by insurance companies that wanted to rate people's health in groups instead of individually.

"Dieting, especially for kids, is the gateway drug for eating disorders, and so is the public shaming that can come with this," Turner said referring to the Fitnessgrams.

"My organization and others believe that BMI report cars have no place coming from schools and can be more harmful than helpful," Turner said.

In the meantime Gwendolyn, who likes to ride the scooter and plays softball, is not taking the Fitnessgram seriously.

"I know that I'm not overweight, so why should I believe the New York Department of Education?" she told the newspaper.