Obesity in children

Special feature • CLINICAL PRACTICE
Obesity in children
Tackling a growing problem
John McLennan, MBBS, FRACP, is a general paediatrician, Bendigo, Victoria.
tions of overweight/obesity in children.2–5 This
and obesity are multifactorial, with changes in
BACKGROUND
demonstrated a rise in overweight and obese
energy intake and expenditure related to both
Childhood and adolescent obesity has
children from 11.8% of boys and 10.7% of
subtle and obvious movements in societal
increased dramatically over the past 25
girls in the 1985 ACHPER study to over 19%
behavioural habits. Technology has con-
years in Australia. Currently over 20%
of boys and 21% of girls in the three
tributed to obesity by making food more
of Australian children are overweight or
1997–2000 studies (Table 1).1–5 Most devel-
abundant, attractive, promoted and simply
obese. The National Health and Medical
oped and some developing countries
obtained. Energy expenditure has been
Research Council has recently developed
worldwide have shown similar trends.
reduced by an increase in sedentary activities,
the 'Clinical practice guidelines for the
management of overweight and obesity
Defining childhood obesity
a decrease in the need to expend energy in
daily routines, and an increase in the use of
in children and adolescents'.
The most widely accepted definition of
cars and other forms of transport. Exercise
OBJECTIVE
obesity relates to the body mass index (BMI):
has now become a formal activity for many
This article discusses the assessment and
weight (kg)/height (2/m). Children above the
children. Fortunately, some of these contribu-
management of childhood and adolescent
85th percentile are classified overweight and
tors have been recognised, acknowledged and
overweight and obesity.
those above the 95th percentile, obese.6
are being addressed. Table 3 outlines the risk
DISCUSSION
There are currently no BMI growth reference
factors for the development of obesity, some
Children and adolescents with a body
charts for the Australian population. Pending
of which are modifiable and some not.
mass index over the 85th centile for age
the development of Australian based refer-
Why childhood obesity
are classified overweight and those over
ence values, the National Health and Medical
matters?
the 95th centile, obese. Obesity has
Research Council (NHMRC) recommends
significant health consequences for
use of the United States Centres for Disease
Effects in childhood
children and adolescents, both in the
Control and Prevention BMI percentile charts
short term and for their adult life. Family
(Figure 1a, b). Less precise guidelines refer to
Short term complications of obesity relate to
involvement is important in management,
being more than 20% above expected
its effects on growing bone, the endocrine,
particularly in primary aged children.
weight for height on standard percentile
cardiovascular, and gastrointestinal systems.
A combination of dietary modification,
charts and the use of skin fold thickness –
These problems are not rare and may be
increased physical activity, decreased
these are not commonly used in children.
identified in most general practices (Table 4).
sedentary activity and behaviour
Why are obesity rates
The prevalence of type 2 diabetes is
modification is recommended.
increasing children and adolescents, particu-
increasing?
larly in certain ethnic groups, including
T
Genetic, endocrine and other medical prob-
Aboriginal and Torres Strait Islanders and
he increasing prevalence of overweight
lems can cause obesity in children. Some
those from middle eastern backgrounds. This
and obese children in Australia since the mid
genetic, endocrine and other medical prob-
increase appears to be associated with high
1980s is well documented. The 1985
lems may have obesity as a significant
levels of obesity in these populations.6
Australian Health and Fitness survey was
presenting factor but the contribution they
Effects in adult life
conducted by the Australian Council for
make to the overall level of obesity is small
Health, Physical Education and Recreation
(Table 2). Apart from Prader-Willi syndrome,
Childhood obesity tracks into adulthood, ie.
(ACHPER) on a sample of over 8000
where hyperphagia is a major issue, the man-
obese children are likely to remain obese
Australian school children, aged 7–15 years.1
agement of obesity in these children is likely
adults, with the associated health risks.
Booth et al compared this data to three more
to be secondary to other problems. The
Studies cited in the NHMRC obesity guide-
recent studies in the light of current defini-
causes of the general increase in overweight
lines reveal that up to 50% of obese
Reprinted from Australian Family Physician Vol. 33, No. 1/2, January/February 2004
33

---

Clinical practice: Obesity in children – tackling a growing problem
Figure 1a, b. CDC BMI percentile charts. Reproduced with permission: Centers for Disease Control and Prevention, 2000
Table 1. Trends in obesity in Australian children
Table 2. Medical conditions
associated with childhood obesity
ACHPER 19851
SFPAS 19973
NNS 19984
HOYUS 20005
n=8492
n=5518
n=2962
n=3104
Chromosomal
Prader-Willi, Down syndrome,
Boys Girls
Boys Girls
Boys Girls
Boys
Girls
Lawrence-Moon-Bardet-Biedl
% overweight
11.8
10.7
20.1
21.3
19.3
22.3
21.1
23.5
Endocrine
or obese
Cushing syndrome, hypothyroidism, GH
deficiencies, hypogonadism
Source: Booth2 as cited in NHMRC guidelines6
Pharmacological
Antimigraine, antihistamine,
antiepileptic, haloperidol, resperidone,
adolescents remain obese in adulthood.7–13
NHMRC,6 the recruitment of Australian
tricyclic antidepressants
The greater the degree of overweight, and
cricket star Brett Lee to encourage increased
Psychiatric
the later in adolescence it persists, the
activity and fitness in children, and the
Depression, psychogenic polyphagia
greater the likelihood of adult obesity. In addi-
increasing availability of ‘low fat’ options on
tion, obesity in childhood is associated with
the fast food market.
increased adult cardiovascular mortality,
What can GPs do?
seem to recognise they are overweight or
regardless of adult weight.14–18
have accepted their stature. However, they
Community role
With so much community activity, what is
may be unaware of both the short term and
the role of the medical profession and, in par-
adult health consequences of obesity in their
Recognition of the rising incidence of obesity
ticular, general practice? The effects of
children. The role of the medical profession,
has led to responses such as the issuing of
obesity on self esteem, mood and social
therefore, should be to:
new dietary guidelines for children and ado-
interaction are understandable, but seem
•
identify obesity
lescents and management guidelines for
insufficient for many to motivate change in
•
discuss health related factors, and
childhood and adolescent obesity by the
their habits and lose weight. Many do not
•
recommend effective interventions.
34
Reprinted from Australian Family Physician Vol. 33, No. 1/2, January/February 2004

---

Clinical practice: Obesity in children – tackling a growing problem
Table 3. Risk factors for obesity6
Table 4. Pathology associated
with obesity
Nonmodifiable
Modifiable
Genetic predisposition: parental
Television viewing: US studies show positive
Orthopaedic
obesity is a strong risk factor for
correlation between television viewing and
Slipped femoral epiphysis, genu valgum
future obesity
overweight (evidence is not yet available for
Endocrine
other small screen entertainments)
Diabetes type 2, advanced growth,
Ethnicity: overweight and obesity is Reduced physical activity energy expenditure
early puberty, polycystic ovary syndrome
higher in those of middle eastern
Cardiovascular
and Mediterranean origin
Hypertension, hyperlipidemia,
A number of single gene
Disordered eating in a parent
cor pulmonale
abnormalities (Table 2)
Respiratory
Medical conditions (Table 2)
Certain medical conditions (Table 2)
Obstructive sleep apnoea, Pickwickian
syndrome
High weight for gestational age
babies
Hepatic
Fatty liver, cholelithiasis
Low weight for gestational age
babies with rapid catch up
Psychological and social problems
Impaired psychosocial function
is greater in females and with
NB: The role of diet composition in the role of overweight/obesity in children is unclear and more
increasing age
studies are required to elucidate this. Breastfeeding is protective against childhood obesity
Adult obesity and complications
Assessment of obesity
Acanthosis nigrans and those from certain
To identify, assess and monitor children with
ethnic backgrounds (eg. Aboriginal and
of all the conventional components of weight
obesity it is important to:
Torres Strait Islander, middle eastern).
management.6 These are:
•
calculate BMI and plot this on percentile
Management of obesity
•
dietary modification
charts, and
•
increased physical activity
•
measure waist circumference. Although
Before considering an intervention, it needs
•
decreased sedentary activity
there are as yet no Australian reference
to be established whether the parents, and
•
family involvement, and
values for waist circumference in chil-
preferably the child, agree there is a problem.
•
behaviour modification.
dren, direct measurements of central fat
Familial factors, whether physiological, psy-
The following strategies are suggested to
correlates with cardiovascular risk.6
chological or cultural, are relevant. Change
stimulate ideas that may make a difference:
Establishing a baseline and serial mea-
will not occur without agreement and motiva-
•
Encourage appropriate eating patterns
surements are important in monitoring
tion in a family setting.
from a young age – see Table 5 and
response to interventions.
The NHMRC guidelines state: ‘For children
NHMRC website for current guidelines
and adolescents, there is (level III–2) evidence
•
Parents should have an appropriate body
Investigations
that weight management programs that
image of their children, ie. it is normal to
Generally, investigations are not necessary for
involve parents achieve better outcomes than
see a child’s ribs
overweight or mildly obese children. For those
programs that do not. For children of primary
•
School canteens should actively promote
with moderate obesity, and associated physi-
school age ... a program that involves parents
appropriate eating patterns
cal signs, blood glucose (postprandial), serum
alone does better than one that requires
•
Avoid using food as a reward
lipids, liver function tests, ultrasound of the
regular attendance by their children as well’.
•
Encourage an increase in casual activity,
liver and thyroid function tests should be con-
The evidence for effective intervention for
eg. walking to school
sidered. In some cases investigation for an
obesity is not strong. There is a single review
•
Reduce sedentary pursuits, especially
underlying medical cause may be appropriate,
in the Cochrane Library.19 A meta-analysis was
those associated with eating, eg. after
eg. chromosomes, adrenal function, growth
not possible because of the variation in popu-
school television. Lose the remote control!
hormone. The NHMRC recommends:
lations, measurements of obesity and aims of
•
Information about dietary recommenda-
•
a fasting lipid profile should be considered
outcomes. To be expected, specialist clinics
tions in the waiting room might include
in obese children and adolescents, partic-
with physicians, dietician and psychologists
the idea of BMI. Offer to measure BMI
ularly those with a family history of
and, presumably, motivated clients did best.
and help with weight loss if parents
cardiovascular risk factors
In the absence of clear evidence as to
agree. Aim for a small initial weight loss,
•
fasting insulin and glucose should be con-
which strategies are the most effective in
celebrate it and consolidate it
sidered in obese children, particularly with
childhood and adolescent obesity, the
•
Encourage a long term change of life
a family history of type 2 diabetes,
NHMRC recommendations are to make use
habits. Look for positives in these
Reprinted from Australian Family Physician Vol. 33, No. 1/2, January/February 2004
35

---

Clinical practice: Obesity in children – tackling a growing problem
material in their surgeries, contact with
primary school children, 1985–1997. Int J Obes
Table 5. NHMRC
patients, and community activities (eg. visits
Relat Metab Disord 2000;24:679–681.
6.
The NHMRC. Clinical practice guidelines for the
recommendations for healthy
to schools) – have a duty to include obesity in
management of overweight and obesity in chil-
eating in children20
their list of preventable diseases.
dren and adolescents. Canberra: Common-
wealth Department of Health and Ageing, 2003.
Encourage and support breastfeeding
Summary of important points
Accessed at: http://www.obesityguidelines.gov.au.
7.
Guo SS, Huang C, Maynard LM, et al. Body mass
Physical activity is important for all
index during childhood, adolescence and young
children and adolescents
•
Children with a BMI over the 85th centile
adulthood in relation to adult overweight and
Enjoy a wide variety of nutritious foods
for age are classified as overweight.
adiposity: the Fels Longitudinal Study. Int J
•
Children with a BMI over the 95th centile
Obesity Relat Metab Disord 2000;24:1628–1635.
Children and adolescents should be
encouraged to:
for age are classified as obese.
8.
Kelly JL, Stanton WR, McGee R, Silva PA.
•
Follow NHMRC recommendations for
Tracking relative weight in subjects studied lon-
•
eat plenty of vegetables, legumes
gitudinally from ages 3-13 years. J Paediatr Child
and fruits
healthy eating in children and adolescents.
Health 1992;28:158–161.
•
Involve parents in weight management in
•
eat plenty of cereals (including
9.
Peckham CS, Stack O, Simonite V, Wolft OH.
bread, pasta, rice and noodles),
children, particularly those of primary
Prevalence of obesity in British children born in
preferably wholegrain
school age.
1946 and 1958. BMJ 1983;286:1237–1242.
•
A combination of dietary modification,
10. Braddon FEM, Rodgers B, Wadsworth MEJ,
•
include lean meat, fish, poultry
Davies JMC. Onset of obesity in a 36 year birth
and/or alternatives
increased physical activity, decreased
cohort study. BMJ 1986;293:299–303.
sedentary activity and behaviour modifica-
•
include milks, yoghurts, cheese
11. Stark O, Atkins E, Wolff OH, Douglas JW.
and/or alternatives (reduced fat
tion is recommended for treatment of
Longitudinal study of obesity in the National
milks are not suitable for children
overweight and obese children.
Survey of Growth and Development. BMJ
1981;283:13–17.
under 2 years but reduced fat
varieties should be encouraged for
Resources
12. Freedman DS, Srinivasan SR, Valdez RA, et al.
Secular increases in relative weight and adiposity
older children and adolescents)
BMI percentile charts are available on the Royal
among children over two decades: The Bogalusa
Children’s hospital website at:
•
choose water as a drink (alcohol is
Heart Study. Pediatrics 1997;99:420–426.
http://www.rch.org.au/emplibrary/genmed/
not recommended for children)
13. Freedman DS, Shear CL, Burke GL, et al.
cdc_bmiboys.pdf
Persistence of juvenile onset obesity over eight
Care should be taken to:
http://www.rch.org.au/emplibrary/genmed/cdc_bmi
years: The Bogalusa Heart Study. Am J Public
•
limit saturated fat and moderate
girls.pdf
Health 1987;77:588–592.
total fat intake (low fat diets are not
NHMRC obesity management guidelines:
14. Power C, Lake JK, Cole TJ. Measurement and
www.obesityguidelines.gov.au. Hard copies are
suitable for infants)
long term health risks of child and adolescent
available free to GPs. Order forms are on the website
•
choose foods low in salt
fatness. Int J Obes 1997;21:507–526.
NHMRC. Food for Health: Dietary guidelines for
15. Freedman DS, Dietz WH, Srinivisan SR,
•
consume only moderate amounts
children and adolescents in Australia. Canberra:
Berenson GS. The relation of overweight to car-
of sugars and foods containing
Commonwealth Department of Health and Ageing,
diovascular risk factors among children and
added sugars
2003. Available at: http://www.nhmrc.gov.au/
adolescents: The Bogalusa Heart Study.
publications/order.htm
Pediatrics 1999;103:1175–1182.
To obtain copies of pamphlets, poster or 16. Mossberg HO. Forty year follow up of over-
A4 information booklet phone 1800 020 103
changes apart from weight loss, eg. a
weight children. Lancet 1989;2:491–493.
extension 8654 (toll free number) or email:
17. Must A, Jacques PF, Dallal GE, et al. Long term
sport or physical activity that is seen by
phd.publications@health.gov.au.
morbidity and mortality of overweight adoles-
the child as ‘cool’ and rewarding.
cents. A follow up of the Harvard Growth
Conclusion
Conflict of interest: none declared.
Study. N Engl J Med 1992;327:1350–1355.
18. Nieto FJ, Szklo M, Comstock GW. Childhood
Obesity is an increasing problem in children
References
weight and growth rate as predictors of adult
mortality. Am J Epidemiol 1992;136:201–213.
and will lead to significant morbidity in adults
1.
Pyke JE. Australian Health and Fitness Survey 1985.
19. Summerbell CD, Ashton V, Campbell KJ, et al.
in the next decade. There are already changes
Parkside, SA: The Australian Council for Health,
Physical Education and Recreation Inc, 1987.
Interventions for treating obesity in children. In:
at the macro level with Brett Lee being
2.
Booth ML, Chey T, Wake M, et al. Change in the
The Cochrane Library (4). Chichester, UK: John
appointed as a fitness ambassador specifically
prevalence of overweight and obesity among
Wiley & Sons, Ltd, 2003.
aimed and preventing and reducing obesity,
young Australians, 1969–1997. Am J Clin Nutr
20. The NHMRC. Food for Health: Dietary guide-
lines for children and adolescents in Australia.
articles in the popular press, and some fast
2003;77(1):29–36.
Canberra: Commonwealth Department of
food manufacturers promoting nutritional
3.
Department of Education and Training. NSW
Schools Fitness and Physical Activity Survey.
Health and Ageing, 2003.
AFP
aspects of their products. Unfortunately, the
Sydney: NSW Department of Education and
effects of the convenience of packaged food
Training, 1997.
and decreased activity will require a more indi-
4.
McLennan W, Podger A. National Nutrition
vidual and conscious effort by parents to
Survey User’s Guide 1995. Canberra: Australian
reverse. General practitioners and others in
Government Publishing Service, 1998.
Correspondence
5.
Lazarus R, Wake M, Hesketh K, Waters E.
the health industry – through promotional
Change in body mass index in Australian
Email: mclennab1@iinet.net.au
36
Reprinted from Australian Family Physician Vol. 33, No. 1/2, January/February 2004

---