Archive: Child Obesity in NZ Study
Tagata Pasifika (15th November 2007)
we featured a report on the findings of a study on
Child Obesity in New Zealand that found that
11% of Pacific Island children are
likely to be extremely obese
. That compares with about
5% of Maori and less than
Palagi. From our studio
spoke to the study's author
Dr Ailsa Goulding
from the University of Otago as well as getting reactions from
Dr Sitaleki Finau from the Health Research
Council's Pacific Committee.
To watch their studio discussion just click on this link: Nov 15 - Intro & Child Obesity ( or below the photos )
* The official press release is below:
Ethnic differences seen in extremely obese
(Monday 12th November 2007)
Marked ethnic differences in the rates of extreme childhood obesity in New Zealand have emerged in a nationwide survey headed by University of Otago researchers.
The Ministry of Health-funded National Children's Nutrition Survey took body mass index (BMI) measurements of 3000 New Zealand children aged five to 14 years, with 1000 from each of three ethnic groups: Pacific Island, Maori and New Zealand European/Other.
While it showed a 2.7 per cent incidence of extreme childhood obesity - compared to 4 per cent in the United States - Pacific Island children stood out with a 10.9 per cent incidence of extreme obesity, with Maori children at 5.1 per cent and New Zealand European children at 0.8 per cent.
It is one of the few studies of its type done anywhere in the world and indicates that, of the 576,900 New Zealand children in the five-to-14-year age group at the time of survey, approximately 15,000 would be extremely obese.
Of those, about 6,000 would be of Pacific Island ethnicity, with another 6,000 Maori and 3,000 categorised as New Zealand European/Other.
University of Otago Department of Medical and Surgical Sciences research Dr Ailsa Goulding says the ethnic differences in the prevalence of overweight and extreme obesity were substantial across all age and gender brackets.
"In Pacific Islanders, about one-third of the overweight children displayed extreme obesity, which is a higher proportion than occurred among NZEO or Maori."
"Extreme obesity was also more common among children having low socioeconomic status."
Dr Goulding says the findings that extreme obesity affects 1 in 10 Pacific Island children and 1 in 20 Maori children, compared to 1 in 100 NZEO children emphasises the need to identify affected individuals and provide them with help.
"These children are already so obese that it is bad for their health," she says. "They are in the top one per cent of the weight range for their age group and adults in that weight range usually have at least one health problem."
"We need to convey this to their parents because many of them don't realise the risks for children and don't associate it with bad health."
Dr Goulding says the study provides a strong case for urgent research into the underlying reasons for these ethnic disparities and ways to implement successful strategies to curb this severe obesity in children.
"Ethnic differences in severe obesity may originate from genetic factors, different patterns of eating and physical activity or low socioeconomic status."
Dr Goulding says that - given that diabetes and metabolic syndrome are prevalent in obese Maori and Pacific island adults, with type 2 diabetes occurring in these groups in adolescence - children with extreme obesity are at high risk for these and other related conditions.
For more information, contact: Dr Ailsa Goulding
Professorial Fellow, University of Otago
Tel: (03) 474 7007 ext 8516
or Brigid Feely
University of Otago
Tel: (03) 479 8263
* To listen to a Radio NZ report click here
full published study from
Journal of Pediatrics (November 2007) is reproduced
(Please note that the result tables are not shown very accurately here)
CLINICAL AND LABORATORY OBSERVATIONS
Ethnic Differences in Extreme Obesity
AILSA GOULDING, PHD, FACN, ANDREA M. GRANT, MSC, RACHAEL W. TAYLOR, PHD, SHEILA M. WILLIAMS, DSC, WINSOME R. PARNELL, PHD, NOELA WILSON, PHD, AND JIM MANN, DM, PHD, FRACP
A nationwide representative survey of New Zealand schoolchildren showed a 2.7% incidence of extreme obesity (versus 4% in the United States) but revealed worrying ethnic differences in prevalence. Prevalence percentages (95% CI) were 0.8 (0.4 to 1.9), 5.1 (3.6 to 7.1), and 10.9 (8.9 to 13.3) in New Zealand European, Maori, and Pacific Island groups, respectively. These findings warrant remedial action. ( J Pediatr 2007;151:542-4)
It was recently reported
1 that 4%
of children and adolescents in the United States now have extreme
obesity (defined as having body mass index [BMI] values _99th
percentile for age and sex from the Center for Disease Control
2 with this condition affecting more than 2
million American children in 2005.3 This high prevalence is
regarded as a major public health concern,
because a high proportion of individuals with such extreme
adiposity develop biochemical abnormalities during their pediatric
years. Furthermore, longitudinal investigations from the Bogalusa
Heart Study demonstrated that obesity persisted into adult life in
all such children, with their average young adult BMI values being
Childhood obesity is a current concern in New Zealand, particularly among Maori and Pacific Islanders, two groups with high adult levels of type 2 diabetes and cardiovascular disease. 4,5 The aim of the present analysis was to assess the prevalence of extreme obesity among children in New Zealand and evaluate differences among ethnic groups within this population, by examining BMI values obtained in a representative national sample of school children conducted in 2002. 6
The National Children's Nutrition survey was a
cross-sectional survey of a national sample of New Zealand children
ages 5 to 14 years drawn from 172 schools that was conducted in
2002 and was funded by the New Zealand Ministry of Health. The
protocol was approved by all participating regional health ethics
committees (n _ 13). Full details of the study design are described
6 Although only 22% of the NZ
population of this age are identified as Maori and 9.9% as Pacific
7 oversampling of Maori and Pacific
children was performed to enable ethnic-specific analyses to be
undertaken. Briefly, the study aim was to recruit 3000
participants, with 1000 from each of 3 ethnic groups: Maori,
Pacific, and New Zealand European and Others (NZEO).
Informed written consent was obtained from every participating child and their parents or guardians. When participants indicated that they belonged to more than one ethnic group, ethnicity was assigned to a single category, using recommended procedures 7 : if Maori was one of the groups reported, the participant was assigned to the Maori group. If Maori was not reported but Pacific ethnicity was reported, the participant was assigned to the Pacific group. All remaining participants were assigned to the NZEO group.
In total, 4728 children were invited to participate and 3275 did so. Response rates were 74% in Pacific Islanders, 69.8% in NZEO, and 65.3% in Maori. Anthropometry was performed on 3049 children (51.3% male) whose age distribution is shown in Table I. Trained personnel measured height (portable stadiometer to the nearest 0.1 cm) and body weight (to the nearest 0.l kg), with the children wearing light clothing and no shoes. BMI (kg/m2) was calculated and converted to a z-score, using the US LMS constants.2 Children with z-scores _1.65 and _2.33 (equivalent to _95th and 99th US CDC percentiles for age and sex) were classified as overweight, or as having extreme obesity, respectively. Socioeconomic status was evaluated using the New Zealand Index of Deprivation, which has l0 categories and is assigned from the residential address of participants and 8 dimensions of deprivation. 8
The statistical analysis was carried out using STATA 9.0, using the survey procedures to adjust for the complex sampling design. Schools were the primary sampling unit. Sampling weights, based on the inverse probability of selection, were used. Because the prevalence of extreme obesity was low, Poisson regression was used to obtain the prevalence estimates (95% CI) for the groups of interest. Estimates of nationwide numbers of children exhibiting extreme obesity were calculated by applying our ethnic prevalences to the New Zealand nationwide 2001 Census data. 7
The prevalence of extreme obesity countrywide in New
Zealand children ages 5 to 14 years was calculated to be 2.7% (95%
CI, 1.9 to 3.8), indicating that approximately 15,000 of the
576,900 children ages 5 to 14 years in New Zealand (2001 Census)
7 have this condition. We estimate that of these
about 3000 will be NZEO, 6000 Maori, and 6000 of Pacific Island
The ethnic differences in the prevalences of overweight and extreme obesity we observed were substantial in all age brackets (Tables I and II), with children of Maori and Pacific Island ethnicity having higher prevalences than the NZEO group in both sexes. In Pacific Islanders, about one third of the overweight children displayed extreme obesity (Table II), which is a higher proportion than occurred among NZEO or Maori. Extreme obesity was more common among children having low socioeconomic status. The relative risk was 7.2 (95% CI, 3.7, 14) when the 4 most disadvantaged categories were compared with the remaining 6 categories.
Table I. Number of children surveyed, age- and
sex-specific cut-points of body mass index (kg/m2) used to identify
overweight (BMI > 95th percentile) and extreme obesity (BMI >
99th percentile), and prevalence (95% CI) of extreme obesity found
in boys and girls of different ethnicity
Age (y) n Boys (kg/m2)* Girls (kg/m2)*
BMI > 95 BMI > 99 BMI
> 95 BMI > 99
5 285 18.1 20.1 18.5 21.5
6 333 18.8 21.6 19.2 23
7 321 19.6 23.6 20.2 24.6
8 316 20.6 25.6 21.2 26.4
9 354 21.6 27.6 22.4 28.2
10 344 22.7 29.3 23.6 29.9
11 297 23.7 30.7 24.7 31.5
12 280 24.7 31.8 25.8 33.1
13 252 25.6 32.6 26.8 34.6
14 267 26.4 33.2 27.7 36
5-14 y 3049
NZEO*** (n _ 936) 0.8 (0.3-2.1) 0.8 (0.2-3.2)
Maori (n _ 1118) 5.8 (3.9-8.8) 4.3 (2.7-6.9)
Pacific Islander**** (n _ 995) 11.4 (8.8-14.8) 10.4 (8.3-13.1)
* At midpoint of each age.
** Results are mean (95% confidence intervals).
*** 82% NZ European, 4% other European, 4% Indian, 5% other.
***** 52% Samoan, 21% Tongan, l4% Cook Islands, 7% Niuean, 2% Tokelauan, 2% Fijian, 2% other.
Table II . Prevalence (95% confidence intervals) of overweight and extreme obesity at different ages
Age group 5-6 y (n _ 618) 7-10 y (n _ 1335) 11-14 y (n _ 1096)
% Overweight (BMI _ 95th percentile for age and sex)
NZEO* 6.9 (3.9-12.2) 7.6 (5.5-10.6) 10.6 (7.6-14.6)
Maori 21 (15.8-27.9) 19.2 (16.1-22.8) 17.4 (13.1-23.1)
Pacific 32.7 (25.5-42) 33.7 (20.4-38.6) 34.4 (31.2-38.1)
% With extreme obesity (BMI _ 99th percentile for age and sex)
NZEO 1.1 (0.3-4.5) 0.2 (0.03-1.7) 1.2 (0.4-3.8)
Maori 8.3 (5.4-13) 4.5 (2.9-7.2) 4 (2.4-6.6)
Pacific 11.8 (7.6-18.4) 10.7 (7.6-14.9) 10.7 (8.1-14.1)
* New Zealand European and other.
The present findings that extreme obesity affects 1
Pacific Island child in 10 and 1 Maori child in 20, versus 1 NZEO
child in 100, draws attention to the need for identification and
remedial treatment of affected individuals.
More research into reasons underlying these ethnic disparities is warranted and ways to implement successful strategies to curb severe adiposity in young children are urgently needed. Ethnic differences in severe obesity may originate from genetic factors, different patterns of eating, and physical activity or low socioeconomic status. Earlier sexual maturity is not a likely explanation because ethnic differences were evident in participants as young as 5 to 6 years. Given that diabetes and metabolic syndrome are prevalent in obese Maori and Pacific adults 9 with type 2 diabetes occurring in these groups in adolescence, 10 we consider children with extreme obesity are at high risk for current and later comorbidities.
We thank the children and parents who participated in the Children's Nutrition Survey 2002. The principal investigators for this survey were from the University of Otago (Winsome Parnell, Noela Wilson), University of Auckland (David Schaaf, Robert Scragg), and Massey University (Eljon Fitzgerald).
1. Freedman DS, Mei Z, Srinvasan SR, Berenson
GS, Dietz WH. Cardiovascular
risk factors and excess adiposity among overweight children and adolescents: the Bogalusa
Heart Study. J Pediatr 2007;150:12-7.
2 . Kuczmarski RJ, Ogden CL, Grummer-Strawn LM, Flegal KM, Guo SS, Wei R,
et al. CDC growth charts: United States. Adv Data 2000;314:1-27.
3 . Xanthakos SA, Inge TH. Extreme pediatric obesity: weighing the health dangers.
J Pediatr 2007;150:3-5.
4 . Simmons D, Thompson CF, Volklander D. Polynesians: prone to obesity and type
2 diabetes mellitus but not hyperinsulinaemia. Diabet Med 2001;18:193-8.
5 . Mann JI, Tipene-Leach DC, Pahau HLR, Joseph NR, Abel S, McAuley KA,
et al. Insulin resistance and impaired glucose metabolism in a predominantly Maori
community. Diabetes Res Clin Pract 2006;72:68-74.
6 . Parnell W, Scragg R, Wilson N, Schaaf D, Fitzgerald E. NZ Food NZ Children:
key results of the 2002 National Children's Nutrition Survey. Wellington: Ministry of
Health; 2003 (available at www.moh.govt.nz/publications).
7 . Statistics New Zealand. 2001 Census of Population and Dwellings; Population and
Dwelling Statistics. Wellington, New Zealand: Statistics New Zealand Te Tari Tatau; 2002.
8 . Salmond C, Crampton P. NZDep2001 Index of Deprivation. Wellington: Department
of Public Health, Wellington School of Medicine and Health Sciences,
University of Otago; 2002.
9 . Gentles DGR, Metcalf PA, Dyall L, Sundborn G, Schaaf D, Black PN, et al.
Metabolic syndrome prevalence in a multicultural population in Auckland, New Zealand.
N Z Med J 2007;120:8, http://www.nzma.org.nz/journal/120-1248/2387/.
10 . Hotu S, Carter B, Watson PD, Cutfield WS, Cundy T. Increasing prevalence of
type 2 diabetes in adolescents. J Paediatr Child Health 2004;40:201-4.
544 Goulding et al The Journal of Pediatrics o November 2007
BMI Body mass index NZEO New Zealand European and Others
From the Departments of Medical and Surgical Sciences (A.G., A.M.G.), Human Nutrition
(R.W.T., W.R.P., J.M.), Preventive and Social Medicine (S.M.W.), and School of Physical Education of the University of Otago (N.W.), Dunedin, New Zealand.
Submitted for publication Apr 3, 2007; last revision received May 14, 2007; accepted Jul 6, 2007.
Reprint requests: Prof Ailsa Goulding,
Department of Medical and Surgical Sciences,
University of Otago, Great King Street,
PO Box 913, Dunedin, 9054 New Zealand.
0022-3476/$ - see front matter
Copyright © 2007 Mosby Inc. All rights reserved.
* To read more TP Articles and watch the relevant stories, just click on the Archive links below the photos...