In the past 40 years, the number of obese children has increased four-fold, according to the National Institutes of Health -- now reaching 17 percent of children and adolescents two through 19 years old.

Much of the current research done by health officials has focused on why kids are gaining so much weight. Is it TV? Lack of sleep? Something in their genes?

Depression considered

Christine Calamaro, PhD, CRNP, assistant professor at the University of Maryland School of Nursing thinks the problem could be depression.

 “My interest in this is not just about the weight of our kids anymore. It is about all the problems associated with obesity. When you start talking about adolescents [emerging] into adulthood, you have to consider co-morbidities, such as depression and diabetes,” said Calamaro.

Recent research on obese children has focused on a link between lack of sleep duration or quality of sleep. Calamaro agrees sleep quality plays a role in weight gain.

“It only makes sense to me that if they are not sleeping well, or have fragmented sleep, then their endocrine balance is screwed up, all their hormones are screw up, their cortisone levels are higher because they are tired and stressed, they are hungry, they eat more, they get carbohydrate-rich foods to get the instant glucose increase, they can get insulin resistance because of weight gain, then eat more carbs to stay awake. It’s a vicious cycle.”

Yet lack of sleep is not the lone culprit. Calamaro led a recent study of 13,568 adolescents from 12 to 18 years old. Those sleeping six or fewer hours a day were no more obese than adolescents sleeping longer.

The finding, part of a study published in the Journal of Sleep Research runs counter to a hypothesis common in adolescent health research, according to Calamaro.

The researchers at first were disappointed, having expected “a slam dunk” relationship between lack of sleep and obesity, she said.

Other factors

But the study did reveal other negative factors were at work.

“In light of other recent analyses that demonstrated a consistent increase in obesity among short sleepers in children and adults, the results of this study raise more questions about the causal pathways that may lead to increased adiposity in adolescents.”

The study showed an association between sleep duration and depression.

Depressed adolescents tended to sleep less than non-depressed adolescents, both in a 12-to-14 age group and in a 15-to-18 age group. Depressed adolescents were almost twice as likely to be obese whereas adolescents who watched television excessively were 37 percent more likely to be obese.

Calamaro and the study coauthors also found that early adolescents who watched more than two hours of TV were 36 percent fatter in later adolescence than those watching less TV.

“Television viewing may lead to increased risk of obesity because watching television has been associated with increased dietary intake, leading to an imbalance in energy expenditure,” the authors said.

Television watching for about two hours per day at the younger age of 12 to 14 was predictive of obesity when they were 15 to 18.

“Childhood obesity is a very complex problem we must address,” says Jay A. Perman, MD, pediatrician and president of the University of Maryland in Baltimore.

According to Perman, fixing the problem will take more than healthcare providers to fix; doctors, nurses, social workers, attorneys, pharmacists and others need to help, too.

Fighting the epidemic

Last year, NIH launched a major effort of $72.5 million in new research funding to examine ways to curtail the nation’s growing childhood obesity epidemic.

According to the NIH Website: “Factors behind this increase are believed to include increased consumption of high-calorie food and drinks and less physical activity during and after school. Overweight and obese children are at higher risk of chronic diseases during childhood and adulthood, including heart disease, stroke, asthma, type 2 diabetes, and several cancers.”

Despite more funding, experts are not catching up with the problem, says Calamaro.

“Preventative care is just not reimbursable (from insurance providers) as much as it should be. In health care we need to focus more on children. By 2043, half the adult population will be obese in the United States” if trends continue and changes are not made, she says.

Change in attitude

Calamaro said preventative care may have to start in infancy now since it could be too late for the current generation.

But getting parents to realize a chubby baby is not a healthy baby is “difficult.”

“We in the primary care setting need to be reinforcing this message about healthy eating/healthy sleep every time parents and children come into the doctor’s office. The hardest thing with obesity is to start the minute that baby first comes into your office and to talk about what healthy eating is for that child: Are you feeding that baby properly with that bottle? When does it look like they are finished drinking from the bottle? Are they warm? Are they dry? Are they crying because they are hungry, or are they crying because babies cry? Basic baby knowledge reinforced over and over again.”