Replacing standard desks with standing desks in school classrooms may be a key to conquering childhood obesity, according to a new study published in the American Journal of Public Health.

In a study co-led by researchers from the University of Louisville School of Public Health and Information Sciences and Texas A&M University, researchers found that using standing desks had a significant effect on the body mass index (BMI) of students.

The study included 193 third-and-fourth-grade students over a two-year period. Children in control classrooms sat at standard desks, while those in the test group studied at what the study calls stand-biased desks, equipped with a footrest and stool.

The unique desks were designed and researched by Texas A&M co-investigators involved in the study and were meant to encourage longer standing periods since students can occasionally sit on a stool and prop their feet on a footrest underneath the desk to relieve back tension and leg fatigue.

At the beginning of the study, researchers recorded the students' height, weight, gender, birth date, and age to calculate their BMI, BMI percentile, and BMI category — normal or underweight, overweight or obese. The same information was collected at the end of the second year.

After adjusting for variables such as race and gender, the researchers found a 5.24-percent decrease in BMI percentile in the group that used stand-biased desks for two consecutive years when compared to the group that used standard desks.

"School-age children spend most of their waking hours during the week at school," said researcher Monica Wendel. "Changing classrooms to stand-biased environments has the potential to affect millions of children by interrupting sedentary behavior, and this can be done simply, at a low cost, and without disrupting classroom instruction."

Wendel says that numerous studies show that prolonged sitting greatly increases the risk of obesity, and that incorporating standing desks in classrooms could have a major impact on public health.

According to the Centers for Disease Control and Prevention, childhood obesity has doubled in children and quadrupled in adolescents during the past 30 years. In 2012, more than one-third of both children and adolescents were overweight or obese.

One study found that 70 percent of obese children had at least one risk factor for cardiovascular disease, such as high cholesterol or high blood pressure. They are also more likely to be obese as adults and have an increased risk for heart disease, Type 2 diabetes, stroke and other devastating diseases.