One emerging feel-good policy for fighting childhood obesity involves schools sending Body Mass Index (BMI) “reports” to parents in hopes of educating them about their kids’ weight. But like many heavy-handed instruments used by nanny-state bureaucrats to suggest lifestyle modifications, this one has unintended consequences.

Consider what happened in one Ohio elementary school when BMI scores were given directly to kids instead of the being mailed to their moms and dads. One parent said her child was declared obese and “refused to eat dinner” as a result of the administrative blunder. Avon Lake (Ohio) Schools Superintendent Robert Scott responded, “It’s unfortunate this happened, but it’s not bad information to have.” (Except, presumably, if it causes kids to develop eating disorders.)

Arkansas made a similar mistake in 2003 by forcing schools to issue fat report cards. The completely predictable results? Thirteen percent of parents said their kids had been teased at school, and the program achieved absolutely no statewide decrease in childhood obesity. (Even when sent directly to parents, there’s no guarantee BMI reports are accurate.)

Overweight children who are stigmatized for their weight can cling to their unhealthy habits. USA Today reports that researchers at the University of Buffalo found overweight kids eat more and exercise less as a result of being ostracized and singled out:

[O]verweight kids seek food for comfort after they feel ignored, says lead researcher Sarah-Jeanne Salvy, an assistant professor of pediatrics … It may be that the children were so focused on dealing with the pain of the ostracism that they stop being as active, Salvy says.

This points to what we’ve been saying all along: BMI report cards are the bureaucratic equivalent of a bully’s “kick me” sign on the backs of some children. Dietary crusaders should understand that humiliating children isn’t a miracle cure for obesity.