Ever wish reading could make you thin? According to a new study released last week by researchers at Duke Children’s Hospital, that just might be the case, at least for preteen girls.

In a pilot study of 81 girls between the ages of nine and 13, reading resulted in a lower Body Mass Index, which measures weight in relation to height. One group of young people were given copies of Annie Bryant’s Lake Rescue (Aladdin, Nov.), the sixth book in the Beacon Street Girls series; a second group was given a different BSG title, Charlotte in Paris. A third control group wasn’t given a book.

The girls who read Lake Rescue, a novel about an overweight 12-year-old at risk for Type-2 diabetes who, with the help of camp counselors, makes positive changes in her life, saw their BMI scores drop (—.71%) after two months. The book echoes many of the themes promoted at Duke’s weight-loss program, like eating breakfast every day, getting plenty of sleep and avoiding juice. The girls who read Charlotte in Paris also saw a dip in their BMI scores, but not as much as those who read Lake Rescue. Those who didn’t read either book actually increased their BMI by .05%.

Although the decrease for readers might seem small, any drop in BMI is encouraging because it typically increases in children as they grow and develop, explains Dr. Sarah Armstrong, director of Duke’s Healthy Lifestyles Program in Durham, N.C. “If their BMI percentile goes down,” she adds, “it means that they are either losing weight or getting taller and not gaining weight.”

Given the overwhelming problem of both childhood obesity and adult obesity, Dr. Terrill Bravender, chief of the section of Adolescent Health at Nationwide Children’s Hospital in Columbus, Ohio, who was involved with the study during his tenure at Duke, was also encouraged. “We’re going to use this to demonstrate that this will be worth investigating further,” he says.