When an Indiana eighth-grader was asked to calculate her body mass index as a measure of her health for a homework assignment, she decided to take her teacher to task.
Tessa Embry, 14, wrote a handwritten essay in response to the question, saying BMI is "an outdated way of defining normal weight." The essay was posted to Facebook by a family friend, where it caught the attention of many on the social media site.
BMI is calculated by dividing a person's weight in kilograms by the square of the person's height in meters, according to the Centers for Disease Control and Prevention.
"BMI can be used to screen for weight categories that may lead to health problems but it is not diagnostic of the body fatness or health of an individual," the CDC says on its website.
As Tessa, a softball player, pointed out in her essay, health experts have said the formula doesn’t differentiate between muscle and fat.
Mindi Embry, Tessa’s mother, said her daughter was distraught earlier this year after she was categorized as "obese" while calculating her BMI as part of a separate PE assignment. The concerned mother told NBC's "Today" she was "furious" the school was "placing a number value on these girls." She made a doctor’s appointment for her daughter to help ease her concerns and the doctor gave the teen a clean bill of health.
"That empowered [Tessa]," Embry said.
So much so, Tessa decided to give the next person who asked her about her BMI a piece of her mind.
"Now, I'm not going to even open my laptop to calculate my BMI. And I'll tell you why," Tessa wrote. "Ever since I can remember, I've been a 'bigger girl' and I'm completely fine with that. I'm strong and powerful. When you put a softball or a bat in my hand, they are considered lethal weapons."
The teen wrote that she was not going to let "some outdated calculator and a middle school gym teacher tell me I’m obese, because I’m not."
"My BMI is none of your concern because my body and BMI are perfect and beautiful just the way they are," she wrote.
Tessa Embry told "Today" she just hopes her response to the assignment will help other students her age "be more educated and wary about the way some people may want to use BMI to label us."
In a statement to NBC News, Evansville Vanderburgh School Corporation said, "All of our students are taught healthy habits in an effort to provide a foundation for a healthy lifestyle."
The school added in the statement that "the question regarding BMI was part of a larger assignment" and praised Tessa for starting a positive conversation.
"I could stand to lose a couple of pounds," Tessa told "Today." "But I'm not necessarily obese; I make very healthy choices. You shouldn't let one number define you."