Policy Brief: Parental Influences on Child Obesity and Dental Caries POLICY BRIEF

Parental Influences on Child Obesity and Dental Caries

Obesity represents a major health and economic threat to Australia by degrading the lives of countless citizens and costing the nation about $58.2 billion in 2010 alone (Crowle & Turner, 2010, p. 32-33). This reality has motivated Australian policymakers to increase the amount of dollars allocated to researching this preventable condition by 5.4-fold between 2003 and 2011 (NHMRC, 2012). A related preventable disease, dental caries, causes untold suffering and represented 10% of all health care spending in 2004/2005 (RACP Paediatric and Child Health Policy Committee, 2013, p. 8). Both of these health issues have had a major impact on child health, which is the primary focus of this policy brief. Most of the research considered here is concerned with children and early adolescents. This issue is examined through the lens of parental influence; specifically in terms of how parents can intervene to control and prevent overweight, obesity, and dental caries in their children.

Why is this Issue Important?

Overweight and obese adults have an increased risk of physical and mental morbidity, and mortality (NHMRC, 2013a, p. 27-29). Type 2 diabetes, heart disease, cancer, and mental illness represent the most common comorbidities in overweight or obese adults. The same comorbidities can affect overweight or obese children, in addition to a number of skeletal, hormonal, airway, and sleep problems manifesting during childhood or early adulthood. The economic burden of this condition for both adults and children was estimated to be $56.6 billion in 2010, of which about $21 billion was due to direct medical costs (NHMRC, 2013b).

A closely related condition to overweight and obese children is dental caries. The prevalence of dental disease in children declined between the 1970s and the late 1990s, but has since been experiencing an upswing (National Advisory Council on Dental Health, 2012) and has become the most common chronic childhood disease by far (Kagihara, Niederhauser, & Stark, 2009). The risk factors, aside from the pain and cost of dental care, include developmental problems, speech disorders, permanent dental disfigurement, eating difficulties, and psychological problems.

World Health Organization (WHO, 2014a) recommendations for addressing these preventable childhood conditions and diseases are eating a healthy diet and increased physical activity. Since the diet and physical activity levels of children are influenced by the adults in their lives, the role of parental influence has received considerable attention (WHO, 2014b).

What Does the Research Tell Us?

Based on 2007 to 2008 data the Australian National Health and Medical Research Council estimated that 25% of the children between the ages of 5 and 17 were overweight or obese (NHMRC, 2013, p. 9). Of these, 8% were obese, but the prevalence of obesity among boys was much higher (10%) than among girls (6%). The prevalence of childhood overweight and obesity began a dramatic upsurge in the 1970s and then stabilized towards the end of the 20th century (Crowle & Turner, 2010, p. 9-10).

The short-term physical consequences of child obesity can include diabetes, high blood pressure, hyperlipidemia, accelerated development, hormonal irregularities, and diseased internal organs (NHMRC, 2013, p. 28-29). The psychosocial consequences include social discrimination, self-esteem problems, eating disorders, depression, and anxiety disorders (Crowle & Turner, 2010, p. 2). More long-term consequences during childhood include constricted airways, sleep apnea, bowing of the legs, hip problems, fractures, asthma, hypoventilation syndrome, and heart failure (NHMRC, 2013, p. 28-29). Unfortunately, overweight and obese children also face an increased risk of adult obesity, premature mortality, diabetes, stroke, heart disease, high blood pressure, asthma, atopy, and disability.

The costs of childhood overweight and obesity are assumed to be similar to other children, so the economic burden of this disease primarily manifests during adulthood (Crowle & Turner, 2010, p. 32-33). When the economic cost of obesity for all ages was examined in 2008 the total cost was $58.2 billion annually. The majority was attributed to the "loss of well-being," a term intended to encompass disability/lost productivity, lower quality of life, and premature death.

A recent study examined the prevalence of decayed, missing, and filled teeth among Australian children, aged 5-6 and 12-years of age (Australian Institute of Health and Welfare, 2011). A history of dental decay was found for 48.7 and 45.1% of the children in the younger and older age groups, respectively. Importantly, the prevalence of dental disease was 70% higher for children in the lowest socioeconomic group when compared to the highest. In addition to the pain, infections, and abscesses caused by untreated caries the quality of the child's nutrition, development, sleep, self-esteem, verbal competence, and academic success can be impacted negatively...

8). In the worst cases, facial disfigurement can occur. The economic impact of dental caries on society is equivalent to diabetes and heart disease, representing 10% of the 2004 to 2005 health care spending in Australia.
The relationship between diet and dental caries appears to be more complex than previously assumed. When Hooley and colleagues (2012a) examined published studies examining this relationship they found a U-shaped curve, such that dental caries was more prevalent among children at both extremes of the body mass index (BMI) continuum. This finding implies that excess calorie consumption resulting in overweight and obesity increases the risk of dental caries, but so does insufficient calorie intake. Accordingly, a normal BMI should be a target of any intervention designed to reduce the incidence of dental caries.

Overweight, obesity, and dental caries are preventable conditions and diseases. The WHO (2014a) characterizes overweight, obesity, and dental disease as natural outcomes of malnutrition due to dietary excess. Accordingly, parents can have a significant impact on these health issues by influencing the quality of a child's diet and the amount of physical activity engaged in (WHO, 2014b). Savage and colleagues (2007) offer a different perspective on the role parents can play in the health outcomes of their children. In the not too distant past the greatest threat to child health was a lack of food and infectious diseases, but in contemporary developed nations the greatest threat to a child's health is unlimited access to simple sugars, fats, and commercial marketing that promotes a lifestyle of habitual consumption. Their recommendation would be to develop an intervention that would reeducate parents about this shift in health threats to their child and promote an eat-when-hungry dietary approach for both parents and child. Unfortunately, an empirical knowledge base that could serve as a foundation for an evidence-based intervention does not exist (Skouteris et al., 2011). In addition, the scientific studies that have examined the impact of parental influence interventions have almost universally ignored objective measures of child health outcomes like BMI.

What are the Implications of the Research?

The evidence supporting an association between diet/physical activity and overweight/obesity is strong; however, the scientific findings linking diet to dental caries is less conclusive. If a general conclusion were to be made, it would be that a healthy diet and lifestyle would carry the least risk of overweight, obesity, and dental disease in children. Any intervention achieving this goal would have a significant positive impact on child and adult health, resulting in a major reduction in health care spending and lost productivity over the course of an individual's life. Parental influences are generally assumed to play a major role in a child's dietary and physical activity habits, but the research examining this relationship suffers from poor methodology, small sample sizes, and a bias favoring positive findings.

Considerations for Policy

Everyone seems to agree that parents represent a major factor controlling the health outcomes of their children. Optimal evidence-based interventions do not exist (Skouteris et al., 2011; Hooley, Skouteris, Boganin, Satur, & Kilpatrick, 2012b), so researchers and parents are forced to make educated guesses about how best to promote healthy weight, dietary habits, and lifestyles for children. In the absence of this knowledge base, the obvious policy recommendation would be to increase funding of disease prevention research focused on child obesity and dental caries. Given the economic impact of these health issues, the additional investment should reap future reductions in health care spending and disability.

The empirical evidence showing a strong relationship between overweight/obesity and diet/physical activity is extensive, so interventions designed to improve parenting habits tend to focus on parental lifestyle choices and parenting styles (Skouteris et al., 2011; Hooley, Skouteris, Boganin, Satur, & Kilpatrick, 2012b). As Hooley and colleagues (2012b) mention, the behavioral component of any effective intervention will probably be significant, so research collaborations between psychologists and dentist could accelerate progress towards evidence-based interventions. Research dollars allocated to disease prevention could therefore increase the number of grants funding collaborative studies that examine the causal relationship between parental behavior and child BMI and dental disease. The efficacy of the many recommendations offered by the authors cited here, such as educating parents about the health threat that excess calorie consumption represents, could thus be tested empirically.