Data, Causes and Risk Factors

Childhood obesity has reached epidemic proportion in the United States and throughout the world.

Prevalence of Obesity

  • According to the Centers for Disease Control approximately 17% or 12.5 million U.S. children and teens are obese. In the past 3 decades, obesity prevalence among children and adolescents has nearly tripled. Nearly one-third of children ages 6-19 are overweight or obese. The rapid rise of childhood obesity has alarmed public health agencies, clinicians, researchers, and the public
  • Significant racial, ethnic and socioeconomic disparities exist in the prevalence of obesity. Of black, non-Hispanic girls aged 12-19, 42% are either overweight or obese. Of Hispanic boys aged 6-11, 43% are overweight or obese.

Trends in Obesity

  • In the past 25 years, the epidemiology of obesity in the United States has changed dramatically. The following maps and detailed trends are available at the Centers for Disease Control.
  • In 1990, among states participating in the Behavioral Risk Factor Surveillance System, ten states had a prevalence of obesity less than 10%, 34 states had a prevalence between 10-14%, and no state had a prevalence at or above 15%.
  • By 1999, no state had a prevalence less than 10%, and only 6 states had a prevalence below 15%. 25 states had a prevalence of obesity between 15-24%, and 19 states had an obesity prevalence greater than 20%. No state in 1999 had a prevalence equal to or greater than 25%.
  • In 2009, only Colorado and the District of Columbia had a prevalence of obesity less than 20%. Forty states had a prevalence between 20-29%. Nine states (Alabama, Arkansas, Kentucky, Louisiana, Mississippi, Missouri, Oklahoma, Tennessee, and West Virginia) had a prevalence of obesity equal to or greater than 30%.
  • By 2010, twelve states had an obesity prevalence greater than 30%. No state met the Healthy People 2010 goal to lower obesity prevalence to 15%.
  • In 2012*, twelve states had an obesity prevalence greater than 30%. Thirty states had an obesity prevalence between 25% and 30%. (*Important Note: Prevalence reflects BRFSS methodological changes in 2011, and these estimates should not be compared to those before 2011.)
  • Click HERE to see maps of the obesity trend from 1985 to 2010.

Obesity in Tennessee

  • The statistics for the state of Tennessee are even more alarming. Our region is one of the worst in the nation, with the 2010 America's Health Rankings placing Tennessee as the 6th heaviest state, and with the 3rd-largest rise in obesity. According to the 2007 National Survey of Children's Health, Tennessee ranked 47th (50 being the worst) in the prevalence of childhood obesity, with 37% of our children either overweight or obese. Tennessee ranked 49th in protective factors against childhood obesity and ranked 40th for healthy neighborhood environments.
  • Across the state of Tennessee, there is wide variation from county to county. For county-specific data, visit the Centers for Disease Control website.

Social-Ecological Model of Influences on Childhood Obesity

  • The contributing factors leading to the childhood obesity epidemic are numerous and complex. This complexity is an important reason why physicians face such difficulty in its management. Genetics, culture, environment, socioeconomic status, ethnicity, geography, politics, and even religion all have an impact on obesity. It is important for physicians to recognize that childhood obesity is not primarily a medical problem; it is a cultural problem with medical consequences.

Causes of the Obesity Epidemic

  • American children eat more, eat worse, and are less active than ever before. Portion sizes have sky-rocketed, so that children are continually being offered more food than they need. In younger children, the problem is often overfeeding rather than overeating. Studies indicate that when children are allowed the opportunity to self-select their portion sizes, they consistently eat less food than when they are served by someone else. (Children's bite size and intake of an entrĂ©e are greater with large portions, Am J Clin Nutr, 2003).
  • In addition to an increase in amount of food, the types of food consumed has also changed dramatically. Contributing factors to the obesity epidemic include more frequent dining out, fast-food restaurants, consumption of pre-packaged meals, and consumption of sweetened beverages (such as sodas, juice, sweet tea, sports drinks, and specialty coffee drinks).
  • Finally, children are less active than ever before. As lifestyles within the home have become busier than ever, less time is available for active play. Physical education at school continues to decrease, and fewer children walk to school. Active play has been replaced by sedentary activities such as television, computer, and video game play.
  • The result of eating more food, making poorer choices in the type of food, and being less active is that American children (and adults) have steadily gained weight.

Risk Factors

  • The prenatal environment plays an important role in a child's future risk of being overweight or obese. As pediatricians, it is vitally important that we take every opportunity to education future mothers about these risks. An infant begins life at risk of obesity if his or her mother had diabetes during pregnancy, was overweight when pregnancy began, had abnormal weight gain during pregnancy, or if either parent has a history of obesity. But, the mother's nutrition extends beyond too much weight gain, and even includes too little weight gain. Malnutrition and smoking also serve as independent risk factors for later childhood obesity.
  • When babies are born, additional factors have been identified as risk factors. Extremes of birth weight (LGA or SGA), bottle feeding, rapid weight gain in the first six months, and early introduction of solid foods and cow's milk all predispose an infant for being overweight or obese.
  • Throughout childhood and adolescence, additional factors are recognized as risk factors. Some of these, such as disordered sleep patterns and the child's temperament (particularly children requiring instant gratification), seem to be intrinsic. Others are lifestyle habits reflective of the family and school environment, such as a sedentary lifestyle, consumption of sweetened beverages, and a high amount of screen time (television, computer, electronic and video games).
  • Research to understand the complex factors causing childhood obesity is ongoing. The prevention of obesity is far easier than its treatment; therefore, it is vital for pediatricians to recognize and address risk factors as early as possible in a child's life.

HEALED Contact Information

Rebecca Robinson, MPH
Training Coordinator
Phone: 865-657-3437
Fax: 615-383-7170