Understanding Childhood Obesity


Childhood obesity is a growing epidemic and is a national concern with lasting effects on health and wellbeing. Research shows childhood obesity has doubled in children and quadrupled in adolescents over the past 30 years (1). Statistics from the Centers for Disease Control and Prevention (CDC) estimate 17% (or 12.7 million) of today’s youth (between 2-19 yrs.) are now considered obese (2). Health related consequences of childhood obesity include increased incidents of high cholesterol, hypertension, type 2 diabetes, sleep apnea, joint/bone problems and poor self-esteem (1). Consequently, children who are obese are more likely to remain obese as adults, perpetuating the obesity epidemic (3). As such, today’s fitness professional must understand the basics of childhood obesity and strategies for helping their young clients live active and healthy lifestyles.

Defining Childhood Obesity

Childhood obesity occurs when a child has too much body fat and is well above the normal weight for his or her height. Body Mass Index (BMI) is a common tool used by health and fitness professionals to classify a child’s weight status. While BMI does not directly measure body fat like skinfold measurements or bioelectrical impedance, it is one of the most widely used tools by health professionals to determine overweight and obesity levels for the general population. BMI is calculated using the following formula:


703 × height (inches) / weight2(pounds) = Adult BMI


A desirable BMI for an adult is between 18.5 and 24.9. Scientific evidence indicates the risk for chronic disease such as cardiovascular disease, cancer, osteoarthritis, and type 2 diabetes increases with a BMI of 25 or greater (4).

A child’s BMI score is determined in a slightly different manner than an adult’s BMI. A child’s BMI score is calculated using a specific percentile of BMI based on the child’s age and gender instead of the same BMI categories used for adults because a child’s body composition fluctuates as they grow. Growth charts from the CDC (http://nccd.cdc.gov/dnpabmi/Calculator.aspx) are then used to determine a child’s BMI.

= BMI at or above the 85th percentile and lower than the 95th percentile

= BMI at or above the 95th percentile

Racial and Socioeconomic Disparities

Childhood obesity prevalence is not equal among all ethnicities or socioeconomic classes. Obesity rates are higher among Hispanics (22.4%) and non-Hispanic black youth (20.2%) than non-Hispanic white youth (14.1%) (2). The occurrence of obesity is lowest among non-Hispanic Asian youth (8.6%) (2).

In addition, childhood obesity is less common in which the head of household has completed a college degree and the household income is above the poverty line. According to the CDC, “Overall, obesity prevalence among children whose adult head of household completed college was approximately half that of those whose adult head of household did not complete high school (9% vs 19% among girls; 11% vs 21% among boys) in 1999–2010” (2).

Poor Diet / Lack of Exercise

Children and adolescents are more sedentary than ever before. They are less active and no longer spending their free time engaged in physical activity (playtime). Instead they are spending increasing amounts of time engaged in sedentary behaviors such as watching television, using computers, and playing video games. Physical education and after-school sports programs are also being cut from school budgets, further decreasing the amount of physical activity in children’s lives. The end result is inactive, unhealthy, and obese children, particularly when combined with poor dietary habits.

Speaking of poor dietary habits, research demonstrates that adolescents are drinking more soda (filled with calories and sugar) and eating less fruits and vegetables (4). Children and adolescents are also consuming too much sodium and do not meet guidelines for whole grain consumption (4). Whole grains, milk, and fruits and vegetables are being replaced with junk food, fast food and soda filled with sugar, saturated fats and excess calories.

Due to the alarming increase and understanding of childhood obesity, new youth fitness guidelines have been developed. According to the U.S Department of Health and Human Services, children should get 60 minutes (or more) of physical activity daily (5). Children should engage in aerobic, muscle-strengthening, and bone-strengthening activities daily to improve their health and reduce their risk of developing obesity and obesity-related disease. A similar recommendation by the National Association for Sport and Physical Education (NASPE) recommends that children ages 5 to 12 get up to 60 minutes of exercise and up to several hours of physical activity daily (6).

Combining healthy food choices with physical activity guidelines will provide children and adolescents the opportunity to live healthful lives reducing the incidence of obesity and associated chronic diseases (i.e., heart disease and diabetes).

Take Home Message for Fitness Professionals

Some parents are reaching out to fitness professionals to help with their child’s weight loss efforts. Parents have many demands on their time and find using a fitness professional is an effective way to help their kids live a healthy lifestyle. With that said, today’s fitness professional should be armed with the latest facts before adding children or adolescents to their client list. First, a child’s weight status is determined using a percentile of BMI, rather than BMI itself. Collecting this information prior to the first training session can help gauge a child’s success as their weight improves throughout a training program. Second, fitness professionals should encourage 60-minutes or more of physical activity per day. This is the child’s “homework” in addition to structured training sessions. Lastly, fitness professionals should provide easy-to-understand information about healthful eating including the importance of consuming fruits, vegetables, low-fat dairy and whole grains. By having a basic understanding about the aforementioned topics, fitness professionals can help today’s youth become more fit and grow to be healthy and active adults.


  1. Ogden CL, Carroll MD, Kit BK, Flegal KM. Prevalence of childhood and adult obesity in the United States, 2011-2012. Journal of the American Medical Association 2014;311(8):806-814.

  2. Centers for Disease Control and Prevention. http://www.cdc.gov/obesity/data/childhood.html. Accessed June 15, 2015.

  3. Centers for Disease Control and Prevention. http://www.cdc.gov/healthyyouth/obesity/facts.htm. Accessed June 15, 2015.

  4. Centers for Disease Control and Prevention. http://www.cdc.gov/healthyyouth/nutrition/facts.htm. Accessed June 15, 2015.

  5. Centers for Disease Control and Prevention. http://www.cdc.gov/healthyyouth/physicalactivity/facts.htm. Accessed June 15, 2015.

  6. Corbin C, Pangrazi R. Physical Activity for Children: A Statement of Guidelines for Children Ages 5–12. Reston VA: National Association for Sport and Physical Education; 2004.