Feb 19 2010

Graehm Gray: Childhood Obesity Definitions – Part One

I guess by now, everyone, everywhere has heard that President Barack Obama and First Lady Michelle have placed childhood obesity on the top of their “to get rid of” list. I think its actually ahead of some Republican pundits. Yes, childhood obesity has finally made it to the front page headlines. All of us in the press and academic fields have known for quite a while that our children have been gaining weight at an alarming rate. The President informed us that over 30 percent of our children are either overweight and or obese. We also have known that our children are not exercising as much. It doesn’t take a rocket scientist to figure out that there is an imbalance-more calories going in and less calories being burned up. Result: a positive weight gain. Okay-that’s means overweight. But the one item that still needs clarification is: how do I know if my child is overweight or obese? I need to know that definition. So here is a sampling of what I could find out:  

  1. Merriam-Webster-doesn’t have a definition of childhood obesity. Their definition of obesity is: a condition characterized by the excessive accumulation of fat in the body (Merriam-Webster)
  2. Medilexicon.comIdeal Body Weight: a weight that is believed to be maximally healthful for a person, based chiefly on height but modified by factors such as gender, age, build, and degree of muscular development.(Medilexicon.com)


  1. Healthline.com-An overweight child is one that has a BMI greater than 95 percent of children their age and gender. Healthline.com
  2. Wikipedia Childhood obesity is a condition where excess body fat negatively affects a child’s health or wellbeing. Wikipedia
  3. National Heart Lung and Blood Institute (NHLBI): Body mass index (BMI) is a measure of body fat based on height and weight that applies to both adult men and women BMI= Mass (kg)/ (height (m)) 2.  (NHLBI) BMI Categories:
  • Underweight = <18.5
  • Normal weight = 18.5-24.9
  • Overweight = 25-29.9
  • Obesity = BMI of 30 or greater
  1. Centers For Disease Control and Prevention (CDC):

Body Mass Index (BMI) is used as a screening tool to identify possible weight problems for children and risk of weight-related health problems. BMI measures excess body weight for a particular height. CDC and the American Academy of Pediatrics (AAP) recommend the use of BMI to screen for overweight and obesity in children beginning at 2 years old. For children, BMI is used to screen for obesity, overweight, healthy weight, or underweight. BMI is NOT a direct measure of body fat but has been shown to correlate with body-fat. For example, a child may have a high BMI for age and sex, but to determine if excess fat is a problem, a health care provider would need to perform further assessments. These assessments might include skin fold thickness measurements, evaluations of diet, physical activity, family history, and other appropriate health screenings.



Obesity defined: Obesity is the result of caloric imbalance (too few calories expended for the amount of calories consumed) and is mediated by genetic, behavioral, and environmental factors and can lead to health risks as elevated cholesterol, triglycerides and insulin levels, high blood pressure, sleep apnea, orthopedic complications and mental health problems.


How Do You Determine A Child’s Weight Status: (Body Mass Index Measurement in Schools, Journal of School Health d December 2007, Vol. 77, No. 10 d ª 2007, American School Health Association) Weight Status in a child and adolescent is determined by comparing their BMI to other youth of the same sex and age in a reference population. Childhood growth changes are taken into account. Once the BMI is calculated for a child, it is plotted by age on a sex-specific growth chart and converted to percentiles. A child’s BMI-for age is then identified.  (For example a 10 year old boy at the 95th percentile has a higher BMI than 95 out of every 100 10 year old boys in the reference population).


BMI-for-age weight status categories and the corresponding percentiles are shown in the following table.

Weight Status Category Percentile Range
Underweight Less than the 5th percentile
Healthy weight 5th percentile to less than the 85th percentile
Overweight 85th to less than the 95th percentile
Obese Equal to or greater than the 95th percentile


Obesity consequences: Obese youth are more likely to have risk factors for cardiovascular disease, such as high cholesterol or high blood pressure. In a population-based sample of 5- to 17-year-olds, 70% of obese youth had at least one risk factor for cardiovascular disease. Children and adolescents who are obese are at greater risk for bone and joint problems, sleep apnea, and social and psychological problems such as stigmatization and poor self-esteem. Obese youth are more likely than youth of normal weight to become overweight or obese adults, and therefore more at risk for associated adult health problems, including heart disease, type 2 diabetes, stroke, several types of cancer, and osteoarthritis.


So there you have it. This is part one of my search for the explanation of what childhood obesity is, how it is defined, what makes a child overweight and what makes him or her obese. Which populations are more at risk, causes and solutions in my next installment.


If we can all agree on what the definition of childhood obesity is, we can look at our own children and see if they have a high BMI and or are they at risk. It is always up to us, as parents to look out for our children. It is our responsibility. Let’s not place the entire blame on the schools, the teachers, the fast food restaurants, the food companies or our government. We need all of them to help us help our kids. It needs to be a group effort. So to paraphrase the words of our First Lady, Michelle Obama, “let’s move!”


Posted in: Editor's Page,Home