This work examines childhood obesity, its foundations, and strategies for reducing its prevalence. There is currently a plethora of information, opinions and sometimes contradictory data surrounding the subject. Although overweight and obesity has existed presumably since the dawn of mankind, it has been relatively uncommon in most societies. Historically, only the wealthy have had the ability to overindulge.
However, in the last several decades the incidence of obesity has increased substantially among adults and children. Thus, it is clear that something(s) about our society creates an environment in which obesity is commonplace. But what and to what extent is not as clear. Consequently, this review seeks to consolidate the literature by addressing the causes and effective treatments for childhood obesity in a way that provides an accurate informational resource for stakeholders who may include health professionals, parents and community members with a commitment to engage this challenge. We need to find solutions for childhood obesity.
Is Childhood Obesity an Epidemic?
Obesity is a condition in which an individual suffers from an excess of body fat and associated health disparities. Since its prevalence is becoming continuously more frequent in the developed world, it raises concern. Consequently, in the United States childhood obesity statistics are quite appaling. 16.9% for children. Perhaps this is little surprise given that 34.9% of adults are obese. Thus it has been defined by the World Health Organization as a global epidemic. 1, 2, 3
Becoming obese is easier than ever, particularly for children. Activity levels in general have been declining for decades and foods high in sugar and fat are more common than ever before. 4 In fact, the rate of obesity among children in the United States in 1963 was a mere 4.2%. It then grew to 15.3% by the turn of the century. It is not only a significant cause of disease and ultimately death in the United States, but is also very costly. At the present time, healthcare expenditures corresponding to obesity are $190 billion annually in the United States. 5 Childhood obesity is of particular interest as children that are overweight are as much as 6.5 times more likely to remain so in their adulthood years. 6
A Thorough Review of the Available Literature
Consequently, a review of the literature reveals three general factors which contribute to childhood obesity. Specifically, they are genetics (including the phenotypic manifestation resulting from environmental factors) , overeating and limited exercise. Research also suggests that, although not a simple task, managing each is practical given the proper resources and support.
The Causes – Is Childhood Obesity the Parent’s Fault?
Childhood Obesity Genetic Fact0rs
Not surprisingly, genetics play a role in obesity and determine the level of predisposition that one possesses for the disease. Humans have a natural propensity to store fat for use as energy, but in the modern world it is much easier to consume many more calories than can be (or are) expended, thus promoting fat storage. 7 This feature of the human race is clearly more prominent in some individuals than others, but only rare cases of hormonal imbalances virtually guarantee the afflicted will suffer from obesity. 8
Familial Studies and What They Show About Obese Kids
Furthermore, multiple studies of twins, siblings and adoptees, indicate that genetics contributes from 40%-70% of inter-individual variation with respect to obesity. Thus, the obese phenotype clearly runs in families with some family units that tend to struggle with weight problems and others that do not. While there is no doubt that genetics contribute to weight loss, it is still not clear what genes are involved and to what extent. The genes that probably affect obesity only contribute a very small amount toward the actual disease, approximately 0.17kg/m2 according to one study. So far 42 genes have been identified as “likely” being associated with BMI and more are expected to be discovered. 9
How Dopamine Affects a Child’s Weight
Additionally, the influence that genetics have on BMI can be seen through one study that found a correlation between dopamine release and obesity. Those with a greater genetic tendency to activate the “reward circuitry” of the brain through the release of dopamine tended to have a higher BMI than those whose stimulation-level was lower. 10 Another study suggests that levels of leptin release, the hormone that determines fat storage levels and is ultimately controlled by genetic factors, plays a role as well. Consequently, children born with abnormal leptin levels quickly gain weight. And although the condition can be treated by injections, those who suffer from leptin deficiency experience hyperphagia (abnormally large appetite), impaired satiety (feeling of fullness) and fat deposition. These effects of course lead to an increased intake in calories and fat storage and result in childhood and later adult obesity. 3(p.37)
Accordingly, what is known for certain is that genetics is a contributing factor in childhood obesity. Precisely which genes play a role and to what extent still remains somewhat unclear. Surely further studies will tell. 11
Sedentary Lifestyles Contribute Immensely To the Childhood Obesity in America
Many children overeat, whether they have a genetic tendency toward obesity or not. A commonly sedentary lifestyle only provokes the circumstances and society additionally provides many temptations. For instance, these may include fast food, high-fat, low nutrient school lunches , vending machines full of treats and soda in schools and unhealthy snacks at home. 12 The CDC reports in a 2013 study that poor eating practices that are thought to promote obesity such as drinking soda, avoiding fruits and vegetables and skipping breakfast are common among today’s youth. 13 Furthermore, research has linked this mode of lifestyle to an increase in calories and fat and a corresponding decrease in the consumption of fruits and vegetables. This pattern seems to be established prior to adolescence. 12, 14 Such frequent exposure to so many unhealthy, but appetizing options establishes an environment that makes the battle against childhood obesity difficult to win.
Kids that are Obese are Almost Never Getting Much Exercise
Correspondingly, the third risk factor for childhood obesity is lack of exercise. The activity–level of children has steadily declined since the 1970’s and currently only about one-third of children are ‘at play’ for the daily recommended 60 minutes. Not surprisingly, the children of today illustrate this perpetual deterioration quite well. In fact, a recent study in which the aerobic capability and endurance level of youngsters was tested illustrates this. Researchers discovered that their young subjects took 90 seconds longer to run one mile than they did in the 1970’s. 15
A poor emphasis on physical activity in school and at home are major contributing factors to this trend as well as a decrease in “grass roots” sports and time spent in physical activity during and after school. 16 In fact, the CDC reported on a survey of high school students and found that 14% are obese. Yet more than half did not attend a physical education class in a typical week and fewer than 50% played on at least one sports team throughout the school year. 13
Television Watching Contributes to a Sedentary Lifestyle and Lack of Exercise
Additionally, television has been a major contributor to childhood obesity. It promotes a sedentary lifestyle that often continues into adulthood and also leads to an increased risk of smoking and high cholesterol. According to the Kaiser Family Foundation report of 2010, children watch an enormous 10.45 hours of media per day, 50.4% higher than in 1999.17
The level of inactivity associated with television viewing for greater than two hours per day during childhood and adolescence is attributable to approximately 17% of the overweight problems. It also accounts for 15% of the poor fitness, 17% of the smoking and 15% of high cholesterol among 26-year olds, according to a study done by Hancox et al 18. Other studies have shown that children who watch television for more than five hour per day are at a risk of obesity as much as five times greater than those that watch two hours or less per day. 3
Advertising in Television Targets Children
While not all studies find a strong positive correlation between television viewing and childhood obesity, advertising may explain this relationship. Since children and adolescents see the obesity-promoting food and drinks that are advertised, they ultimately obtain and consume them. Thus the problem is perpetuated beyond the simple sedentarianism associated with television viewing 19, 20(p.123). This theory is further bolstered by a 2012 study that involved 12,600 children in grades 5-10 that found that kids who watched the most TV tended to have the worst eating habits. Of course this does not prove that TV causes poor eating, but rather that a strong correlation exists between the two. However, this is a figurative one-two punch since television watching by its nature is a sedentary activity, therefore promoting obesity. But poor eating habits associated with watching television also fosters even further weight gain. 20(p.123), 21
Who Has More of an Obesity Problem, Boys or Girls?
There are also a number of contributing factors that play a role in the genetics, diet and activity level of children including sex, socio-economic status and race. Studies have shown mixed results on whether boys or girls as a group tend to be more obese. Nevertheless, there are clear distinctions among views and actions regarding diet and exercise. 22, 23 Girls tend to place a greater value on nutrition as a way to influence their health whereas boys eat more fast foods. Girls also show fewer tendencies to exercise than boys, reporting fewer role models, greater barriers and fewer perceived benefit. 22, 24
Are Poor Kids Fatter? – Childhood Obesity and Poverty
Socio-economic status (SES) also correlates strongly with childhood obesity. In particular, one study by Wang and Lim in 2012 indicates a linear relationship among SES and obesity.25 Moreover, these results show that the lower the SES, the higher prevalence of obesity and greater the risk of adulthood obesity and additional health problems associated with the condition. Specifically, cardiovascular disease, diabetes, psychological disorders and hyperlipidemia are just a few. 25, 26, 27 Black and Hispanic children, who often come from lower income homes, are also more likely to have a television in their bedroom, consume more sugar-sweetened drinks and eat more fast food than white children. This of course fosters a higher risk for obesity. 28
Childhood Obesity by Race
Research has additionally demonstrated that race is a significant risk factor for childhood obesity. This is presumably in part because of its strong association with socio-economic status. Blacks and Hispanics both have a higher risk associated with childhood obesity than whites. 29 This even begins prior to birth with a higher incidence of maternal depression among these minority groups. Following birth, children of minorities are more likely to experience rapid weight gain, receive solid foods prior to four months of age, and display higher rates of maternal restrictive feeding habits. 28 Although the reason is not clear as to why the early introduction of food may promote obesity, a study of 847 infants found that weaning prior to four months had a significantly higher risk of developing obesity by the age of three years. 30
Does What You Eat as an Infant Have Anything to do with Obesity?
Minorities are also less likely to receive exclusive breastfeeding, another factor that may help determine the risk of childhood obesity. Accordingly, the study just mentioned, the breastfed infants, even those that were weaned as early as four months, did not have a higher risk of developing obesity by age three. However, those who were never breastfed, those whose mothers stopped breastfeeding prior to four months and those who were introduced to solid food prior to four months had a higher chance of becoming obese by age three; six times greater than those that were exclusively breastfed for at least four months. 30
Fatigued vs. Energized
Black and Hispanic children are also more likely to get less sleep than white children. Thus, they are more likely to be obese as a child and an adult. 31 So while sleep deprivation is a risk factor that is common among all races, minorities experience disproportionate amounts of fatigue. Further studies have linked a lower adulthood BMI to children who get more sleep and a higher adulthood BMI with those that get less. 32
Review of the Causes of the Childhood Obesity Epidemic in America
It is clear that one cannot blame parents for entirely for their children being obese. There is little question that factors such as genetics are outside of their influence. However, there are a multitude of factors that parents can control. Limiting television time and junk food as well as choosing breastfeeding and encouraging activity are some ideas. After all, while there is a disparity between races and financial resources, this only represents an average. Race and access to money themselves do not make a child obese.
Potential Childhood Obesity Interventions
1. Early Detection
In the first place, it may come as no surprise that early detection is an important factor in determining if a child is at risk for obesity. Consequently, pediatricians may perform a simple test known as the body mass index (BMI). Consequently, this can be easily done by comparing the weight to the height of the child. 33 A BMI in the 85th percentile or higher constitutes overweight status. Of course, these kids are at high risk for various health disparities. Furthermore, a measure within the 95th percentile indicates obesity and significant health-related risk. Appropriate action should be taken, even for children approaching the 85 percentile because intervention is likely to fail once a child has become obese. 34
2. Childhood Obesity Interventions
Whether a child is already overweight or obese or at risk of becoming so, reversing the trend is entirely feasible. But positive results require effort on the part of healthcare providers, policy-makers and parents. 1 Few, if any children will take matters into their own hands. And although solutions for childhood obesity can be a challenge to implement, they can be successful with the right support. 35 In one study that utilized family involvement and incorporated a calorie goal, self-monitoring of food intake and physical activity, mean weight loss was 2.4lbs. after 15 weeks. The control group actually gained a mean weight of 3.45lbs. 36
Similarly, findings from a number of studies that utilize multiple lines of support indicate a similar trend. Interventions that include school, community and home-base support are typically most effective at reducing overweight and obesity. On the other hand, school or home-base only interventions tend to be ineffective. Thus, the trend indicates that with more support comes more success. 37
3. Lifestyle Changes can Affect Childhood Obesity in America
Interventions should not only attempt to help the child lose weight, but adopt new lifestyle changes that continue into adulthood. If these attempts fail long term, particularly in the age group of 12 years old and under, there is evidence that such can lead to eating disorders. For instance, in one study of 588 participants, researchers found a strong association between weight loss attempts in childhood and the development of binge eating disorder (BED) in adulthood. Participants were only eligible if they had a BMI of more than 25kg/m2 or 24kg/m2 and at least one risk factor for cardiovascular disease. The risk associated with the development of BED as a result of weight loss attempts in childhood proved linear with respect to age of first attempt. Therefore, the younger the child at their first attempt to lose weight, the greater the risk of developing BED. 38
4. Healthy Eating is Hard to get Kids to do but is a Huge
Children who are at risk for being overweight or obese should also be taught healthy eating habits. Following these practices will reduce their risk of obesity and many other health disparities. 39 The earlier this happens, the less likely the child will have weight problems as an adult. Additionally, this should take place in the home. This is the “first line of defense,” where success is most likely. 3
Few children, particularly younger ones, will prove capable of managing food intake in a responsible and effective manner. Thus, parents must take an active role.40 However, they must be cautious in their level of control as children who are shown too little or too much control are likely to develop problematic eating habits. So, they should begin at infancy teaching children proper eating practices and providing wholesome foods at predictable and agreeable times. This allows more autonomy as they grow. Slowly, children will learn to make healthy food choices for themselves as they mature into adulthood. 41
5. Parental Involvement is a Deal Breaker in Terms of a Child’s Success
Research has shown success is much more likely when there is parental involvement. One meta-analysis for example shows that parental involvement was largely effective, at least in the short-term. This happened over the course of fifty studies involving obese children ages 0-6. 42 In another study that relied on parental paticipation to help reduce the weight of their 4-11 year-old children, all 101 participants maintained intervention effects after one year. 43 A 2014 meta-analysis of 36 randomized, controlled studies of child weight-reduction interventions that required parental involvement resulted in an average BMI of nearly 1.2 kg/cm2 less than children in the control groups. 44
Many studies illustrate the importance, and arguably necessity of parental involvement in weight reduction for obese children. Although few have shown to be effective in long-term weight maintenance. This may be due to lack of parental skills more than parental participation. In other words, ONLY during interventions do parents usually receive coaching. Yet once the intervention ends, their lack of skills may allow their child to return to previous behaviors. 42
Finally, all children need exercise to improve their health and decrease their risk of health disparities. Since many are already overweight or obese, they have an even greater need. 45 Physical exercise burns calories that otherwise would likely end up in fat stores, but also engages health-promoting processes that benefit the entire body. 46, 47 Not all studies have shown a strong negative correlation between exercise and obesity in children. But all those done in conjunction with dietary programs have, providing one of the best solutions for childhood obesity 3 Still, parental inclusion is key once again as children are far more likely to engage in physical activity when parents are motivators. The children will feel empowered through supportive autonomy that minimizes pressure and control. 45, 48
Conclusions Regarding Childhood Obesity
There are many factors that determine obesity in children. Yet all fit into the classification of genetics, diet or activity-level. Genetic factors determine what an ideal bodyweight is for a given individual and does vary from child to child. However, few children have a genetic guarantee that they will be obese (BMI above 30). 8 So although genetics may make it impossible for a particular individual to obtain a ‘super-model figure’, diet and exercise remain factors that can be managed. In order to avoid obesity and improve health, children must be taught proper diet and exercise habits. This necessitates parental involvement that ideally includes other stakeholders. For example, teachers and healthcare professionals who provide guidance and help the child to learn to manage their own nutritional and physical needs are essential. 3, 40, 41, 45, 48