Healthy Bmi Ranges In Early Childhood Age Groups

The rise in prevalence of childhood obesity in the United States over the last four decades is alarming. According to the U.S. Department of Health and Human Services, 16 percent of children between the ages of 6 and 19 were overweight in that time period. Parents and pediatricians should take measures to track their child's weight and height over time; this information can be used to calculate the BMI, or body mass index. The BMI is the most important tool to diagnose obesity. Evidence suggests that early interventions can prevent many of the complications of obesity later in life.

Body Mass Index

BMI is used by clinicians to get a rough idea of a person's nutritional status. The formula for BMI factors in an individual's height and weight. Normal values in the adult population are approximately 18.5 to 24.9; values between 25 and 29.9 are considered overweight and those between 30 and 34.9 are considered obese. A BMI over 40 is classified as morbidly obese.

BMI in Children

Children are different from adults because they are in an active state of growth and undergo a variety of changes during this time. The amount of fat stores in children changes over time as they grow. Instead of using BMI to assess for obesity, pediatricians use a variation of this formula by taking the BMI for age. A child's BMI is compared to the reference range for his age. For example, the 95th percentile of BMI in a 4-year-old is 19, whereas it is 25 in a 13-year-old.

Diagnosing Obesity

BMI percentiles from 5 to 84 for age are considered normal weight. Values from 85 to 94 for age are classified as "at risk for overweight" and those over the 95th percentile for age are classified as obese. However, BMI measurements can overestimate weight in muscular children. Doctors can track a child's change in BMI over years by using convenient charts provided by the Centers for Disease Control. Separate charts are available for boys and girls. Other tools that can be used to assess for nutritional status are skinfold thickness, ultrasound, total body conductivity and air-displacement plethysmography, which is a technology that uses air to measure body fat . While BMI has many disadvantages, it is most commonly used by doctors as it can be measured inexpensively and reliably.

Complications of Obesity

The importance of tracking a child's BMI lies in the fact that obesity is associated with a number of complications. Besides social stigmatization which can be damaging to a child's self-esteem, childhood obesity is associated with an increased risk of hypertension, high cholesterol, diabetes and heart disease later in life. Behavioral changes such as limiting screen time and increasing physical activity have shown promise in preventing many of these complications. An article in "Diabetes Care" published in 2008 points out that diagnosing obesity early in life can "help allocate resources for intensive interventions that may benefit individuals at greatest risk for early obesity-related morbidity."