To the editor:
Recently, BMI screening in public schools has come under fire with the emergence of letters sent home to parents indicating their child’s BMI percentile and weight category. Not only has the screening come under harsh criticism, but the increasing incidence of obesity in Massachusetts children has been challenged based on erroneous assumptions and propaganda that BMI is an inaccurate measure of a child’s body fat.
BMI screening is just that; a screening tool. It is used in the surveillance of children by the U.S. Centers of Disease Control and the World Health Organization internationally. A screening tool is used to identify children with possible weight problems and not as a diagnostic or clinical decision-making tool. While BMI in adults is reported as an absolute number — a person’s weight in kilograms divided by their height in meters squared — in the pediatric population it is reported as a percentile. Absolute BMI numbers in children are widely varied and are therefore compared with children of the same sex and age based on widely used pediatric growth curves to develop percentiles. While they clearly are not indicative of every child that is overweight, many studies have been completed which have validated BMI as an adequate measure of body fat in children and as a reasonable index of those patients at high risk of long-term complications.
Current estimates show that approximately 16 percent of Massachusetts children between the ages of 2 and 5 are overweight, and an additional 16 percent are categorized as obese. Not convinced by BMI percentiles? The rate of type II diabetes in childhood and adolescence is also on the rise, a disease primarily prevented by maintaining a healthy weight and previously seen largely in adults. The overall incidence of heart disease continues to rise in Massachusetts and is directly linked to obesity as one of its strongest risk factors.