School BMI Screening Tied to Reduced Weight Satisfaction Among Youth

By Lisa Rapaport

November 19, 2020

(Reuters Health) - School-based weight checks and BMI reporting don't appear to impact BMI z scores and may increase the potential for youth to become dissatisfied about their weight, a California study suggests.

Researchers randomized 79 public schools in California to one of three groups: BMI screening alone, BMI screening combined with reporting, or control groups without BMI screening or reporting. Researchers assessed BMI z scores and weight-related outcomes for a total of 28,641 youth in grades 3 through 7 for up to three years.

Among the 6,534 students (out of 16,622 screened) with a BMI in the 85th percentile or higher (39.3%) at baseline, there was no significant difference in the change in BMI z scores during the study period, researchers report in JAMA Pediatrics.

Compared to youth who didn't get weighed at school, those who did experienced a bigger decline in weight satisfaction and a bigger increase in weight-related teasing from peers, the study also found.

"The U.S. stigmatizes overweight and obesity, which makes the process of being weighed highly sensitive for some children," said lead study author Dr. Kristine Madsen, faculty director of the Berkeley Food Institute at the University of California, Berkeley.

"I think BMI reporting is just a bad idea, at least in grades 3 and up," Dr. Madsen said by email.

It's possible when children are younger that informing parents about BMI when they still have a lot of ability to control what children eat might help children maintain a healthy weight, Dr. Madsen said. However, unless healthy options are accessible and affordable, BMI reports are unlikely to do much to prevent childhood obesity, Dr. Madsen said.

"As with other major public health efforts that have saved lives - such as eradication of communicable diseases, reductions in tobacco use, and increases in seat belt and car-seat use - we need to pair education about obesity with effective legislation and environmental changes to achieve greater population health," Dr. Madsen said.

The study team used a peer weight-teasing index with scores ranging from 1 for "never" experiencing this to 5 for "almost every day." Compared with youth who were not weighed in school, those who were had a 0.05-point larger increase in teasing from peers over two years.

In addition, researchers used a weight satisfaction index with scores ranging from 1 for "very unhappy" to 5 for "very happy." Compared with youth who not weighed in school, those who were had a 0.11-point bigger decline in weight satisfaction scores over two years.

One limitation of the study is that results from students in California may not be generalizable to youth elsewhere, the study team notes. There was also a small proportion of African-American students in the study, which could also limit generalizability.

Even so, the results underscore the importance of focusing on healthy behaviors and discussing weight in a non-stigmatizing way, said Dr. Tracy Richmond, director of the Boston Children's Hospital's Eating Disorder Program and co-author of an editorial accompanying the study.

"Every kid, no matter their weight or BMI, deserves to feel good about their bodies," Dr. Richmond said by email. "Every kid, no matter their BMI, could benefit from counseling focused on healthy habits such as regular physical activity, reducing sugar sweetened beverage consumption, eating mindfully and not eating while watching screens."

Beyond this, clinicians who discuss weight with young patients should focus on providing tools to help patients and families make healthy choices rather than focusing only on BMI, Dr. Richmond said.

"Delivering health messages explicitly focused on weight has the potential to be very stigmatizing and lead to lower weight-related self-efficacy and can lead to adoption of behaviors opposite to what we hope," Dr. Richmond said.

SOURCE: and JAMA Pediatrics, online November 16, 2020.