Just as adult obesity has become an ever growing epidemic, childhood obesity has also become a worldwide problem. Despite efforts to reverse this trend, there have been very few interventions that have helped combat the growing problem of childhood obesity. Childhood obesity leads to adult obesity and both carry a number of medical problems that are associated with increased adiposity, such as higher risks for type 2 diabetes, high blood pressure, heart disease, stroke, and even some forms of cancer. In combination with the growing physician shortage in the United States, the obesity epidemic has the makings of an impending society and healthcare disaster. Something must be done to slow or stop this trend. Two out of every three Americans is now overweight, and this trend has continued unabated for the past half century. Combating childhood obesity by understanding its causes is a first step in reversing this ominous trend that is poised to ravage the health of our future citizens.
Researchers, led by Dr. Ashley Cockrell Skinner from the University of North Carolina at Chapel Hill, have found that young overweight adolescent consume more calories than their normal weight peers, but that older overweight children consume less calories than their normal weight peers. The results of their study were published online in the journal Pediatrics. The researchers evaluated dietary reports from 12,648 children aged 1 to 17 years old who participated in the National Health and Nutrition Examination Survey (NHANES study) from 2001 to 2008. The researchers used height and weight to calculate weight-for-length percentile and body mass index (BMI), and self-reported diet intake was assessed by repeatedly validated automated multiple pass method. It was found that young obese/overweight children (age 1 to 8 years) consumed more calories and obese/overweight adolescents (age 9 to 17 years) consumed fewer calories when compared to their normal weight peers.
The authors wrote, “In nationally representative cross-sectional data using a previously validated measure, younger boys and girls who are overweight and obese, report greater energy intake than healthy-weight children of the same ages. However, overweight children older than 6 to 10 years reported consuming fewer daily calories than their healthy-weight peers”.
The authors also wrote, “We would expect, based on conventional understanding, that overweight and obese children would consume more calories than healthy-weight children. We found that differences in energy intake by weight status were dependent on age. One possible explanation is that increased energy intake in earlier childhood leads to the onset of obesity, which becomes self-perpetuating… A second reason for the differences in energy intake may be that overweight children are significantly less active, therefore requiring fewer calories to maintain energy balance.”
The authors concluded that, “… our findings have significant implications for interventions aimed at preventing and treating childhood obesity. First, our results emphasize the importance if focusing on prevention of overweight, beginning at very early ages. During infancy and early childhood, obesity is often not recognized by parents or clinicians, yet this is potentially a time to encourage parents to recognize satiety, pay attention to portion size to avoid overfeeding, and increase nutrient density of foods chosen. Second, particularly during adolescence, focusing on activity may prove to be a more useful strategy than encouraging caloric restriction.”
This study sheds light on the age of onset of childhood obesity and suggests that portion control should begin before the age of 9 years to prevent the onset of obesity. After the age of 9 years, children are already eating less and thus increased physical activity should be recommended. This study also suggests that ounce extra weight is gained; it becomes increasingly difficult to lose the weight by calorie restriction. Another technique that may be beneficial may be to limit the percentage of calories consumed from carbohydrates. Carbohydrates cause insulin secretion, which prevents lipolysis and causes excess calories to be stored in fat tissues. Ultimately, this study points out that calorie restriction is already occurring in overweight children and other techniques will need to be employed to reverse the weight gain.
Ashley Cockrell Skinner el al. “Self-Reported Energy Intake by Age in Overweight and Healthy-Weight Children in NHANES, 2001-2008” Pediatrics published online September 10, 2012 doi: 10.1542/peds.2012-0605