Childhood obesity is of central concern to primary care professionals, both for the immediate psychological and physical effects it may have for the child, but also for the increased likelihood of the child developing adult obesity and the increased risk of diseases such as Type 2 diabetes, cardiovascular disease and cancer. The risk of childhood obesity begins prior to the birth of the child, with genetics as well as the antenatal environment influencing risk of later obesity. Primary care has a potential role to play at this stage. During infancy and childhood, primary care professionals also have numerous opportunities to assess, manage and monitor potential overweight and obesity in children, from the times of postnatal care and breastfeeding to immunization visits, preschool checks and during visits for minor illnesses. This chapter addresses each stage, discussing assessment, and suggesting ways of translating evidence into primary care at a practice and policy level to reduce childhood obesity.

Assessment and monitoring

Maternal nutrition and well-being are areas where health professionals may influence subsequent childhood obesity rates and their consequences. Barker showed an association between low birth weight and weight at the age of 1 year in determining the risk of cardiovascular disease (CVD) in later life, especially in children who showed “catch-up” growth or became obese. Barker’s research prompted international studies and public health recommendations to promote maternal nutrition and infant growth, largely through primary health care.¹ Fetal and early postnatal nutrition were thought to be the “common soil” that program the metabolic syndrome. This “common soil” hypothesis, postulated originally in 1984, suggested that early nutrition was a common link in the development of Type 2 diabetes and CVD, implying that CVD is not a complication but shares genetic and environmental antecedents with Type 2 diabetes.² Experimental rat studies have demonstrated that poor maternal nutrition is associated with increased insulin resistance and elevated blood pressure in the off-spring.³ Accelerated weight gain during infancy is also associated with increased insulin resistance as well as overweight and higher leptin and blood pressure levels in adolescence and adulthood.³ Maternal over-nutrition is also of concern, as higher birth weights are associated with higher BMI during childhood and adulthood, as well as increased risk of obesity and diabetes.

Management

Therefore, the management of maternal nutrition is important in reducing obesity during childhood and later (and for many other reasons). Early detection and careful management of gestational diabetes in primary care is essential with not only the potential for congenital abnormalities and macrosomia if poorly controlled, but also increased adiposity and insulin levels even at the age of 5 years.³ In the UK, the NICE guidance on maternal and child nutrition recommends the provision of information on the benefits of a healthy diet and practical and tailored advice on healthy eating throughout pregnancy.⁴ Low birth weight is associated with subsequent obesity, so smoking cessation interventions in pregnancy are also important as they have been shown to reduce smoking rates and improve birth weight.⁵

As breastfeeding reduces risk for both CVD and Type 2 diabetes, and other benefits of breastfeeding are incontestable, breastfeeding promotion is of paramount importance in primary care and community health facilities. Philip and Radford argue that the risks of being formula fed are now well established.⁶ A systematic review commissioned by the World Health Organization (WHO) and published in 2007 found that breastfed individuals were less likely to be considered as overweight/obese.⁷ Scholten et al’s more recent study examined longitudinal data from 2,347 children born in 1996/97 and found that children who were breastfed for more than 16 weeks had a lower BMI at 1 year than non-breastfed children. A high BMI at 1 year was strongly associated with a high BMI between the ages of 1 and 7 in the same model.⁸

Assessment and monitoring

The US Preventive Services Task Force state that there is insufficient evidence to recommend for or against screening for overweight in children.¹¹ One of the WHO criteria for screening is the availability of effective treatment, which is largely lacking in this area. However, the American Academy of Pediatrics Committee already recommend that primary care pediatricians perform regular screening in children using body mass index (BMI = weight in kg/[height in m]²).¹² The UK set targets in 2002 to “halt the year-on-year rise in obesity among children under 11 by 2010” recommending monitoring of child adiposity through a national scheme to measure all children (including BMI) upon entry to infant school and senior school through primary care trusts.¹³

The use of BMI to identify overweight children is widely recommended for children aged 2–18.^12,14 However, the use of BMI is controversial, as it may not distinguish between weight increases due to fat and those due to fat-free mass, which vary by individual and particularly by ethnic group. ^11,15 Even so, BMI has reasonable correlation with adiposity. The Centers for Disease Control and Prevention BMI percentile charts or the use of locally recommended BMI charts where available, to assess age and gender-specific BMIs, are recommended.^14,15

Overweight is defined by the US Centers for Disease Control and Prevention as being above the 95th percentile of BMI.¹¹ Other countries, such as Australia, have used the 85th percentile as the cut-off for “over-weight” and 95th percentile for “obesity”¹⁴ and the UK recommend tailored clinical intervention with a BMI at or above the 91st percentile. ¹⁵ However, choosing such cut-offs presents the problem that they are linked to the current range of BMI distribution in the reference population instead of being linked to morbidity or health outcomes. Waist circumference is not recommended for routine measurement in children at present, but it measures fat around the dangerous abdominal region, and therefore may be a better indicator of the risk of developing insulin resistance, metabolic syndrome and long-term health problems and may have a place in routine clinical measurement in the future.^14,16

It is important to recognize adverse weight trajectories in childhood both for treatment and prevention, as childhood overweight is predictive of adult overweight and obesity and eating patterns are often established early, so systematic screening may be worthwhile.¹² When overweight or obesity are identified, assessment of the nutritional and physical activity patterns of the child and their family should be undertaken; in particular, the nutritional quality of the food, portion size, snacking behaviors, meals eaten in front of the television, meals eaten with the family, and consumption of breakfast, fast foods and sugar-sweetened beverages. Participation in organized sport or activities, informal physical play, transport to school or other sources of physical activity can be assessed, as well as time spent in sedentary activities such as television watching and computer or other screen games.

The psycho-social setting within the family or school may be influencing these patterns. If a child is identified as being over the 95th percentile in BMI, assessment of obesity-related co-morbidities may be indicated, especially if there is also a family history of co-morbidity, such as Type 2 diabetes, early CVD or familial hyperlipidemia. Occasionally, a pathological cause can precipitate obesity in childhood and may also be associated with reduced height, such as a hypothalamic lesion, Cushing’s syndrome, hypothyroidism or growth hormone deficiency, all of which require more detailed assessment and specialist referral.

It is important to communicate the results of screening to parents in a sensitive way, and to use effective approaches to address the issue, such as motivational interviewing.^12,17 Parent perceptions vary and the best way to discuss these issues with parents needs further research. Some parents report they are made to feel guilty while others are left feeling that the general practitioner (GP) has thought they are unnecessarily concerned about their child’s weight.¹⁸ Qualitative research has suggested that parents may also interpret growth charts and perceive “overweight” differently from health professionals.¹⁹ In a study of maternal anxiety regarding overweight preschoolers, mothers were more likely to be concerned if a child became inactive or was teased by peers rather than worrying about their percentile on a growth chart.¹⁹ An effective way to address the issue may be to establish shared goals and emphasize healthy diet and physical activity rather than focusing on the growth trajectory.

Management

There is currently sparse evidence for the effectiveness of treatment of childhood obesity in primary care.¹⁴ There is some evidence to suggest that weight management programs for overweight or obese children involving weight maintenance rather than weight loss, behavioral strategies, family involvement (preferably motivated family), and an intensive and long-term approach may have some effectiveness, especially those combining dietary, physical activity and reduced sedentary behavior goals.²⁰ For example, physical activity and diet approaches combined are more effective than diet alone in specialist weight management programs.¹⁵ There is some randomized controlled trial (RCT) evidence that interventions in health care settings can increase physical activity, reduce sedentary behavior and in those that are compliant with the program, weight increase can be slowed, with no adverse effects in terms of the child’s growth or quality of life over 12 months, compared with usual dietetic advice.²⁰

One barrier to delivering these interventions in primary care is the often brief nature of the primary care consultation (e.g. 10–15 minutes for GPs, although nurses may have longer). A few “brief” interventions based in primary care designed to improve physical activity patterns in school age children have had some early encouraging results. Interventions to lose weight have been less encouraging. For example a RCT showed that brief physical activity counseling was able to increase physical activity and reduce sedentary time in children over 12 months in the USA. ²¹ Although the counseling was delivered through primary care, computer-based diet and exercise assessment, goal setting and monthly mail and telephone counseling were also part of the intervention. In New Zealand, the Green prescription, an effective brief intervention delivered in primary care to increase physical activity among adults, has been adapted to improve physical activity in children (7–18 years) in a linked program called “Active Families”. Although the advice is initiated in primary care by the GP or practice nurse, the child and their family are referred to a community-based program over 12 months, aiming for 60 minutes of at least moderate intensity activity per day, as well as healthy eating. However, the effectiveness is not yet established.

Ford (US) (2000) tested a primary care intervention to reduce TV watching time over four weeks in a RCT.²² Participants were 7–12-year-old African American children (not necessarily overweight) from 28 families. They compared 5–10 minute counseling with a longer intervention that also involved behavioral strategies, TV budgets and electronic TV time managers. Both groups decreased screen time by 14 hours per week but there was no difference between the groups. There was also a trend towards taking fewer meals in front of TV, and those with the TV electronic monitors did better than those without.

Further research is underway into primary care interventions such as the Live Eat and Play (LEAP) trial in Australia, and a subsequent Australian trial is planned of a multi-component intervention initiated in a hospital child obesity clinic but followed up three monthly in primary care, using computer assisted assessment and decision support.²³

In general, principles of advice given by health professionals to parents or carers should encourage healthy eating, regular meals including breakfast, preferably with family and without distractions such as television, and reducing the consumption of sugar-sweetened beverages.^12,15 Physical activity of at least 60 minutes per day should be encouraged through play, recreational activities or with family, and through reduced sedentary behaviors involving, for example, television, computer or video games. These characteristics are all associated with reduced risk of overweight and obesity, although experimental evidence in primary care is scarce.¹² Training of primary care professionals in counseling techniques and lifestyle behavior change and the appropriate allocation of time and resources are needed.¹⁵ Several countries have encouraged primary care organizations to collaborate or combine strategies with other community agencies or companies, such as supermarkets, schools, local exercise facilities, local authorities, planning agencies (e.g. of cycle tracks or walk ways) and industry.^15,24

Assessment and monitoring

Assessment of the adolescent should include weight and height (BMI) and in those at risk such as those over the 95th percentile of BMI or with a family history of co-morbidity, waist circumference, blood pressure, serum fasting glucose, insulin and lipid levels, and liver function tests. Co-morbidities include psycho-social dysfunction or depression, bulimia or other eating disorder, obstructive sleep apnea, asthma, raised blood pressure, dyslipidemia, metabolic syndrome, insulin resistance or Type 2 diabetes, gall bladder disease, steatohepatitis, polycystic ovarian syndrome and orthopedic complications such as slipped capital femoral epiphyses.

Primary care initiatives need to work within the context of wider organizational and policy changes that support the advice given. At a practice level, the impact of simple advice should not be underestimated, even in light of limited evidence for specific primary care intervention. Partnership and goal-setting with parents, children and adolescents around healthy diets and portion sizes, increasing physical activity and reducing sedentary activities may be effective in reinforcing healthy behaviors. In addition, approaches within everyday practice may need to change. For example, well child checks for the infant and preschool child should focus on “healthy” weights and not “gaining” weight.

At a policy level, health care practitioners often have a voice through overarching primary care organizations to influence the future shape of primary care in addressing issues such as childhood obesity in a systematic and population health focused way. The systematic implementation of evidence-based guidelines into usual primary care practice, such as the UNICEF Baby Friendly Initiative (community) would improve reach of our best evidence for preventing obesity. Electronic prompts and decision support within primary care practice management systems may be a way of prompting systematic screening and guidelines-based management for overweight and obesity in children.³⁰ Quality of care remains ad hoc where evidence-based guidelines are not systematically adopted at the primary care level.

Collaborations between primary care and community or school-based initiatives, facilitated at a policy level, may be needed to achieve a more effective approach to childhood obesity. This would also be in line with the Alma Ata declaration, which defines quality primary health care as integral to, and a central function of, the community and is based on practical, scientifically sound, culturally appropriate, and socially acceptable methods and technology, which is accessible to all age groups.³¹ Furthermore, such an approach is consistent with Article 24 of the United Nations Convention on the Rights of the Child.³²

1 Barker D, Gluckman P, Godfrey K, Harding J, Owen J, Robinson J: Fetal nutrition and cardiovascular disease in adult life. Lancet 1993; 341: 38–941.

2 Singhal A, Lucas A: Early origins of cardiovascular disease: is there a unifying hypothesis? Lancet 2004; 363:1642–1645.

3 Gillman MW, Barker D, Bier D et al: Meeting report on the 3rd International Congress on Developmental Origins of Health and Disease (DOHaD). Pediatr Res 2007; 61:625–629.