Childhood Obesity: Causes

Mike Kemp/Getty Images

Childhood obesity has been on the rise in the United States for several years now, although recent data from the National Center for Health Statistics indicate that obesity rates among children may finally be plateauing. However, the prevalence of obesity among children and adolescents is still high. According to the American Heart Association (AHA), approximately one in three children and teenagers is obese or overweight.

As the AHA notes, this rate is nearly triple what it was in 1963. In fact, childhood obesity has become so alarmingly prevalent and such a threat to children’s health that the American Academy of Pediatrics has an entire website dedicated to the “Prevention and Treatment of Childhood Overweight and Obesity.”​

The Reasons Why: A More Sedentary Lifestyle

A number of studies have investigated the reasons for elevated rates of childhood obesity, with more studies ongoing. A more sedentary lifestyle has certainly been found to be prevalent in many studies, and studies have shown that children who watch television for longer than one hour per day tend to have a higher body mass index (BMI), as well as higher blood pressure. Researchers have suggested that more time spent in front of the television is associated with poor food choices that lead to overweight and obesity, and this in turn increases cardiovascular risk.

It has been shown, for instance, that children who are obese are more likely to have abnormal lipid panels than children who are not obese.

The decline in physical education programs and the time allotted for physical activity during the average school day has also been implicated in the rise in childhood and adolescent obesity.

For many reasons in addition to obesity itself, this decline in physical activity is of serious concern due to the increased risk for cardiovascular disease with lower levels of physical fitness.

High-Calorie Foods

Poor nutrition choices with calorie-dense foods have also been linked to childhood obesity. Many studies have looked at the relationship between certain dietary behaviors, such as consuming sugared beverages, and obesity. However, prospective studies examining the individual impact of each potentially harmful behavior are still ongoing, and it has been noted that the scientific investigation into causal factors has lagged behind the obesity epidemic that has swept the country and much of the world.

The intake of sweetened beverages has received a lot of attention, and research has overwhelmingly pointed to an association between sugared beverage intake and obesity, both in children and adults. In addition, many clinicians note that when their obese and overweight patients follow their recommendations for reducing or avoiding sugared beverage intake, these patients reliably lose weight.

These include both soft drinks and sugar-sweetened fruit drinks.

Large Portion Sizes

Other nutritional factors also appear to play a role. An increase in portion sizes, for instance, has been linked to increased obesity in children. Particularly among adolescents, there is evidence to support the notion that eating away from home—commonly resulting in the consumption of “fast food”—is associated with increased risk for overweight and obesity.


Additionally, a genetic component to obesity cannot be ignored, as obesity has been found to be inherited in certain families. As the “Expert Committee Recommendations Regarding the Prevention, Assessment, and Treatment of Child and Adolescent Overweight and Obesity” has noted: “Twin studies have clearly demonstrated a genetic risk.” Other studies have found that the magnitude of parental obesity may be important, and have shown a link between morbid obesity in parents and subsequent obesity in their children; in other words, the children of morbidly obese parents are at higher risk of becoming obese themselves.


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

2. Jackson E. Abstract, American College of Cardiology 2014 Scientific Sessions.

3. Seery T. Abstract, American College of Cardiology 2014 Scientific Sessions.

4. Barlow SE, et al. Expert committee recommendations regarding the prevention, assessment, and treatment of child and adolescent overweight and obesity: summary report. Pediatrics 2007;120:S164-S192.  

Continue Reading