# Prevalence of Overweight and Obesity in Adolescents: A Systematic Review

Authors: Maria del Mar Bibiloni; Antoni Pons; Josep A. Tur
Journal: ISRN Obesity
 (2013)

---

## Abstract

Objective. To review the extant literature on the prevalence of overweight and obesity in adolescents (10–19 years old) of both sexes.
Design. The search was carried out using Medline and Scopus considering articles published from the establishment of the databanks until June 7, 2012. Data on the prevalence of children being overweight and obese from the International Obesity Task Force (IOTF) website was also reviewed. Only original articles and one National Health Report were considered. Forty studies met the inclusion criteria. Results. Twenty-five of these studies were nationally representative, and ten countries were represented only by regional data. Conclusions. The prevalence of overweight and obesity among adolescents worldwide is high, and obesity is higher among boys. The IOTF criterion is the most frequently used method to classify adolescents as overweighed or obese in public health research.


---

## Body

## 1. Introduction

The prevalence of overweight and obesity among children and adolescents has widely increased worldwide [1, 2], making it one of the most common chronic disorders in this age group and in adulthood.The use of body mass index (BMI) for age to define being overweight and obese in children and adolescents is well established for both clinical and public health applications, because of their feasibility under clinical settings and in epidemiological studies [3, 4]. In children and adolescents, the natural increases in BMI that occur with age necessitate the use of age-sex-specific thresholds. The most widely used growth charts are the Centers for Disease Control and Prevention (CDC-2000) [5], the International Task Force (IOTF) [6], and the 2007 growth references for 5 to 19 year olds produced by the World Health Organization (WHO-2007) [7].The CDC-2000 growth charts were developed to evaluate the nutritional status of US children and were originated from five cross-sectional representative surveys carried out in the US between 1963 and 1994. These growth charts are routinely applied to identify children and adolescents with a BMI greater than the 85th or 95th percentiles following the advice of the US Expert Committee on Childhood Obesity [8]. However, the appropriateness of an American dataset for defining overweight in young people from other countries is questionable [9].The IOTF reference also uses age-sex-specific BMI percentiles, and overweight and obesity definition corresponds to an adult BMI of 25 and 30 kg/m2, respectively, and reflects values in children tracking to overweight and obesity in adults [6]. This reference is based on six large international cross-sectional representative datasets, identifying the BMI values that extrapolate to childhood.The WHO-2007 growth references were created to replace the National Center for Health Statistics (NCHS) references [10, 11]. This reference was constructed using data from the 1977 NCHS/WHO growth reference (1 to 24 years old) merged with data from the 2006 WHO Child Growth Standards for preschool children (under 5 years of age) using state-of-the-art statistical methods [7].Although valuable information has been appearing in the literature or online, such as works from the Health Behaviour of School-aged Children study which is mainly related to social determinants of health and well-being among young people [12], no systematic review has been conducted to understand the worldwide magnitude of the overweight and obesity problem among the adolescent population. Thus, the objective of this study was to systematically review the literature regarding the prevalence of overweight and obesity in adolescents (10–19 years old) of both sexes published in the past 12 academic years (1999–2011).


## 2. Methods

A systematic literature search was performed which ended on June 7, 2012 (see Figure1). The literature search was conducted in Medline and Scopus using the following MeSH terms: “overweight”; “obesity”; “prevalence”; “adolescent”. In total, 2537 articles were selected. We also reviewed the data on the prevalence of childhood overweight and obesity on the International Obesity Task Force Website at http://www.iaso.org/iotf/. To find the articles included in this review, the following inclusion criteria were used: (1) cross-sectional studies conducted in the last 12 years (1999–2011)—when the original study did not report the survey year, it was not included; (2) national and regional representative samples, but articles published on the prevalence of overweight in towns, urban, or rural areas in a country were excluded; (3) weight and height objectively measured; (4) results presented by sex; (5) and for both overweight and obesity prevalence; (6) the definition of overweight and obesity using the (i) CDC-2000 [5], (ii) IOTF [6], and (iii) WHO-2007 [7] growth references; and (7) studies written in English, Spanish, Italian, or Portuguese. Moreover, if there were more than one national or regional study in the same country, the most recent one was included in the prevalence tables (except for USA [13] and Canada [14], countries in which the most recent data was not included in the tables due to differences in the representativeness of the samples [13] and the impossibility to calculate a single prevalence of overweight and obesity for adolescents’ boys and girls [14]; however, no differences in prevalence were observed between studies as it has been indicated in the discussion). The final number of articles included in this review was 39 articles related to overweight and obesity and also a study on the latest statistics on the prevalence of overweight and obesity in South Africa [15].Figure 1
Flow diagram of study selection.Potentially relevant papers were selected by (1) screening the titles; (2) screening the abstracts, and (3) if abstracts were not available or did not provide sufficient data, the entire article was retrieved and screened to determine whether it met the inclusion criteria. Full-text articles were assessed by 2 authors (M. M. Bibiloni and J. A. Tur). Any matter of doubt was discussed by at least two of the reviewers (M. M. Bibiloni, A. Pons, and J. A. Tur).


## 3. Results

### 3.1. Literature Search

A total of thirty-nine articles and a National Health Report were eligible according to the inclusion criteria established for this review. Table1 presents a description of the forty studies selected for this review including the continent and the country where it was performed (and region for not national studies), year of publishing, total number of participants in the study, number of adolescents, age range, proportion of girls, and number and definition for overweight and obesity classification used. All the articles were published after the year of 2002. Nationally representative data were obtained in twenty-five countries (including Northern Ireland) [15–39], and ten countries were represented only by regional data [40, 42, 44, 45, 47, 50–54].Table 1
Descriptive analysis of the studies reviewed.
Area
Continent
Country, region
Date of survey
Totaln of study1
Totaln of adolescents1
Age (years)/school grade
Proportion of girls
Number of definition
Definition
Reference
National
Africa
Seychelles
2004
4,854
2,177
7th, 10th
51.5%
1
IOTF
Bovet et al., 2006 [16]
South Africa
2008
9,862
9,862
13–19
50.9%
1
IOTF
Reddy et al., 2010 [15]
Tunisia
2004
2,872
2,872
15–19
54.9%
1
IOTF
Aounallah-Skhiri et al., 2008 [17]
America
Canada
2004
8,661
4,099
12–17
—
3
IOTF, CDC, WHO
Shields and Tremblay, 2010 [18]
Mexico
2006
48,304
13,219
12–18
50.7%
1
IOTF
Bonvecchio et al., 2009 [19]
USA
2007
44,101
44,101
10–17
—
1
CDC
Singh et al., 2010 [20]
Asia
Bahrain
2000
506
506
12–17
50.8%
1
IOTF
Al-Sendi et al., 2003 [21]
China
2002
44,880
12,475
13–17
47.7%
1
IOTF
Li et al., 2008 [22]
Iran
2003-04
21,111
16,035
10–18
51.3%
2
IOTF, CDC
Kelishadi et al., 2008 [23]
Israel
2003-04
5,588
5,588
11–19
55.1%
1
CDC
Nitzan Kaluski et al., 2009 [24]
Jordan
2009
5,640
637
13–18
55.7%
1
IOTF
Khader et al., 2011 [25]
Qatar
2003-04
3,923
3,923
12–17
49.8%
1
IOTF
Bener, 2006 [26]
Saudi Arabia
2005
19,317
7,251
13–18
49.2%
2
CDC, WHO
El Mouzan et al., 2010 [27]
Taiwan
2003
72,789
58,424
10–18
49.0%
1
IOTF
Liou et al., 2009 [28]
United Arab Emirates
2009-10
1,007
276
11–18
—
1
IOTF
Ng et al., 2011 [29]
Europe
Cyprus
1999-2000
2,467
1,694
10–17
50.7%
1
IOTF
Savva et al., 2002 [30]
Czech Republic
2005
1,417
957
11–17
49.4%
1
IOTF
Kunesova et al., 2007 [31]
Germany
2008
40,622
5,623
12–16
46.7%
1
IOTF
Blüher et al., 2011 [32]
Greece
2003
14,456
14,456
13–19
53.8%
1
IOTF
Tzotzas et al., 2008 [33]
Italy
2002
4,386
4,386
11, 13, 15
51.6%
1
IOTF
Vieno et al., 2005 [34]
Republic of Ireland
2003
17,499
7,294
11–16
50.6%
1
IOTF
Whelton et al., 2007 [35]
Northern Ireland
2003
2,039
964
11–15
51.5%
1
IOTF
Whelton et al., 2007 [35]
Portugal
2008
22,048
22,048
10–18
51.5%
2
IOTF, WHO
Sardinha et al., 2011 [36]
Sweden
2001
1,732
1,732
10, 13, 16
48.3%
1
IOTF
Ekblom et al., 2004 [37]
Oceania
Australia
2004
5,407
1,771
8th, 10th
45.6%
1
IOTF
Booth et al., 2007 [38]
New Zealand
2007
8,796
8,796
13–17
45.4%
2
IOTF, WHO
Utter et al., 2010 [39]
Regional
Africa
South Africa, Eastern Cape
2008
926
926
13–19
52.1%
1
IOTF
Reddy et al., 2010 [15]
South Africa, Free State
2008
1,236
1,236
13–19
49.1%
1
IOTF
Reddy et al., 2010 [15]
South Africa, Gauteng
2008
931
931
13–19
52.1%
1
IOTF
Reddy et al., 2010 [15]
South Africa, KwaZulu-Natal
2008
910
910
13–19
52.1%
1
IOTF
Reddy et al., 2010 [15]
South Africa, Limpopo
2008
1,140
1,140
13–19
50.5%
1
IOTF
Reddy et al., 2010 [15]
South Africa, Mpumalanga
2008
1,238
1,238
13–19
49.8%
1
IOTF
Reddy et al., 2010 [15]
South Africa, Northern Cape
2008
1,088
1,088
13–19
48.6%
1
IOTF
Reddy et al., 2010 [15]
South Africa, North West
2008
1,234
1,234
13–19
48.6%
1
IOTF
Reddy et al., 2010 [15]
South Africa, Western Cape
2008
1,159
1,159
13–19
56.4%
1
IOTF
Reddy et al., 2010 [15]
America
USA, 52 Sates2
2007
—
—
10–17
—
1
CDC
Singh et al., 2010 [20]
Brazil, Pernambuco State
2006
4,210
4,210
14–19
59.8%
1
IOTF
Tassitano et al., 2009 [40]
Asia
China, Hong Kong
2003-04
2,098
2,098
11–18
53.2%
2
IOTF, CDC
Ko et al., 2008 [41]
India, Manipur
2005-06
3,356
3,356
12–19
56.2%
1
IOTF
Bishwalata et al., 2010 [42]
Jordan, Irbid Governorate
2007
1,355
1,355
13–16
55.6%
1
CDC
Abu Baker and Daradkeh, 2010 [43]
Europe
Denmark, Greater Copenhagen area and 3 municipalities outside the Capital Region
2007–09
7,541
7,541
14–16
50.1%
1
IOTF
Søren and Jo, 2010 [44]
France, Aquitaine Region
2004-05
2,385
2,385
11–18
49.1%
1
IOTF
Thibault et al., 2010 [45]
Greece, Crete
2005-06
481
481
10–12
54.0%
1
IOTF
Manios et al., 2011 [46]
Hungary, Szeged and Szolnok regions
2005-2006
14,290
14,290
11–16
48.1%
1
IOTF
Baráth et al., 2010 [47]
Italy, 5 residence regions3
2002
4,386
4,386
11–15
51.6%
1
IOTF
Vieno et al., 2005 [34]
Italy, Sardinia
1999–2001
3,946
3,946
11–15
49.0%
1
IOTF
Velluzzi et al., 2007 [48]
Italy, Sicily
1999–2001
48,897
48,897
11–15
50.7%
1
CDC
Baratta et al., 2006 [49]
Poland, Kujawsko-Pomorskie
2005
—
—
13–15
—
1
IOTF
Jodkowska et al., 2010 [50]
Poland, Lubuskie
2005
—
—
13–15
—
1
IOTF
Jodkowska et al., 2010 [50]
Poland, Malapolskie
2005
—
—
13–15
—
1
IOTF
Jodkowska et al., 2010 [50]
Poland, Podlaskie
2005
—
—
13–15
—
1
IOTF
Jodkowska et al., 2010 [50]
Poland, Pomorskie
2005
—
—
13–15
—
1
IOTF
Jodkowska et al., 2010 [50]
Spain, Balearic Islands
2007-08
1,231
1,231
12–17
53.4%
1
WHO
Bibiloni et al., 2010 [51]
Spain, Grand Canary
2004-05
1,002
1,002
12–14
50.0%
1
IOTF
Henríquez Sánchez et al., 2008 [52]
Switzerland, Canton of Vaud
2005-06
5,207
5,207
10–14
49.7%
2
IOTF, CDC
Lasserre et al., 2007 [53]
Turkey, Edirne Province
2001
989
989
12–17
48.1%
1
IOTF
Öner et al., 2004 [54]
1Only subjects with anthropometric measurements were included in each country.
2There are 52 states in the USA, but no information about total number of subjects was included in each state.
3Vieno et al. [34] assessed the overall overweight and obesity prevalence among Italian adolescents, and also according to the geographic region: North-West, North-East, Center, South, and Islands, but no information about total number of subjects was included in each region.
IOTF: International Obesity Task Force; CDC: Center for Disease Control and Prevention; WHO: World Health Organization.


### 3.2. Prevalence and Criteria for Classification

Table2 shows overweight and obesity prevalence from the twenty-five national studies (one of them including data from Northern Ireland) that were included in this review according to the continent and the country where it was performed, year of survey, study population, age range, criteria used for classifying overweight and obesity used, and along with total data by sex. There were thirty-two different prevalence levels described in the included articles, because five countries presented data using at least two different criteria for overweight and obesity classification [18, 23, 27, 36, 39]. The IOTF cut-off was used to classify overweight and obesity in twenty-three of the twenty-five national studies considered in the present review.Table 2
Description of overweight and obesity prevalence (%) along with total data by sex from each national study that was included in the review according to year of survey, study population, age range, and classification criteria used.
Continent
Country
Date of survey
Study population
Age (years)/school grade
Criteria
Overweight (%)
Obesity (%)
Reference
All
Boys
Girls
All
Boys
Girls
Africa
Seychelles
2004
School-based survey
7th, 10th
IOTF1
12.0
9.5
14.3
5.1
4.2
6.0
Bovet et al., 2006 [16]
South Africa
2008
2008 SA YRBS
13–19
IOTF1
14.4
7.9
20.6
5.3
3.3
7.2
Reddy et al., 2010  [15]
Tunisia
2004
Household-based survey
15–19
IOTF1
12.4
11.0
14.1
2.6
1.9
3.2
Aounallah-Skhiri et al., 2008 [17]
America
Canada
2004
2004 CCHS
12–17
IOTF1
19.8
21.2
18.4
9.4
11.1
7.4
Shields and Tremblay, 2010 [18]
CDC-20002
15.9
17.0
14.7
12.1
14.3
9.6
WHO-20073
20.8
21.9
19.6
12.4
15.1
9.4
Mexico
2006
Household-based survey
12–18
IOTF1
21.2
20.1
22.3
8.9
9.2
8.6
Bonvecchio et al., 2009 [19]
USA
2007
2007 NSCH
10–17
CDC-20002
15.2
15.3
15.2
16.4
19.2
13.5
Singh et al., 2010 [20]
Asia
Bahrain
2000
School-based survey
12–17
IOTF1
20.0
15.3
24.5
16.4
14.9
17.9
Al-Sendi et al., 2003  [21]
China
2002
2002 CNNHS
13–17
IOTF1
4.6
4.6
4.6
0.6
0.7
0.5
Li et al., 2008  [22]
Iran
2003-04
CASPIAN Study
10–18
IOTF1
5.9
5.7
6.0
1.3
1.5
1.1
Kelishadi et al., 2008 [23]
CDC-20002
4.5
4.3
4.7
1.9
2.3
1.6
Israel
2003-04
MABAT Youth Survey
11–19
CDC-20002
12.9
12.7
13.0
5.6
7.4
4.1
Nitzan Kaluski et al., 2009 [24]
Jordan
2009
Household-based survey
13–18
IOTF1
13.7
11.3
15.5
10.0
12.4
8.2
Khader et al., 2011 [25]
Qatar
2003-04
School-based survey
12–17
IOTF1
23.8
28.6
18.9
6.3
7.9
4.7
Bener, 2006 [26]
Saudi Arabia
2005
Household-based survey
13–18
CDC-20002
17.9
16.5
19.6
7.0
8.2
5.5
El Mouzan et al., 2010 [27]
WHO-20073
16.0
13.6
18.4
10.6
11.2
10.0
Taiwan
2003
School-based survey
10–18
IOTF1
16.3
18.4
14.2
6.2
8.1
4.2
Liou et al., 2009 [28]
United Arab Emirates
2009-10
Household-based survey
11–18
IOTF1
—
16.2
20.5
—
11.7
19.7
Ng et al., 2011 [29]
Europe
Cyprus
1999-00
School-based survey
10–17
IOTF1
18.9
21.3
16.5
5.8
7.1
4.5
Savva et al., 2002 [30]
Czech Republic
2005
Lifestyle and Obesity Study
6–17
IOTF1
12.3
16.6
8.0
1.4
1.7
1.0
Kunesova et al., 2007 [31]
Germany
2008
CrescNet database
12–16
IOTF1
18.2
19.3
17.0
6.2
7.6
4.6
Blüher et al., 2011 [32]
Greece
2003
School-based survey
13–19
IOTF1
18.3
23.3
14.0
4.3
6.1
2.7
Tzotzas et al., 2008 [33]
Italy
2002
HBSC Study
11, 13, 15
IOTF1
15.6
20.9
10.6
2.3
3.5
1.2
Vieno et al., 2005 [34]
Republic of Ireland
2003
School-based survey
11–16
IOTF1
18.5
17.8
19.2
5.8
5.6
6.1
Whelton et al., 2007 [35]
Northern Ireland
2003
School-based survey
11–15
IOTF1
18.2
18.5
17.8
5.9
6.0
5.7
Whelton et al., 2007 [35]
Portugal
2008
School-based survey
10–18
IOTF1
17.4
17.7
17.0
5.2
5.8
4.6
Sardinha et al., 2011 [36]
WHO-2007
21.8
20.4
23.1
9.9
10.3
9.6
Sweden
2001
School-based survey
10, 13, 16
IOTF1
15.8
14.6
16.9
4.4
5.0
3.6
Ekblom et al., 2004 [37]
Oceania
Australia
2004
2004 SPANS
8th, 10th
IOTF1
17.9
19.4
16.2
5.3
6.7
3.6
Booth et al., 2007 [38]
New Zealand
2007
Youth’07 Survey
13–17
IOTF1
24.0
23.3
24.7
10.2
10.8
9.5
Utter et al., 2010 [39]
WHO-2007
25.9
25.9
26.0
13.5
14.6
12.1
1Overweight and obesity, all adolescents with BMI-for-age ≥25 kg/m2 and <30 kg/m2 and ≥30 kg/m2, respectively, according to the IOTF [6].
2Overweight and obesity, all adolescents with BMI-for-age ≥P85th and <P95th and ≥P95th, respectively, according to the CDC [5].
3Overweight and obesity, all adolescents with BMI-for-age >+1SD and <+2SD and >+2SD, respectively, according to the WHO [7].
IOTF: International Obesity Task Force; CDC: Center for Disease Control and Prevention; WHO: World Health Organization; 2008 SA YRBS: 2008 South African National Youth Risk Behaviour; 2004 CCHS: 2004 Canadian Community Health Survey; 2007 NSCH: National Survey of Children’s Health; 2002 CNNHS: 2002 China National Nutrition and Health Survey; CASPIAN Study: Childhood and Adolescence Surveillance and Prevention of Adult Non-communicable disease; HBSC: Health Behaviour in School-aged Children; 2004 SPANS: 2004 NSW Schools Physical Activity and Nutrition Survey.There was a broad range of overweight and obesity prevalence noted. In general, the prevalence of overweight plus obesity was higher in America [18–20], Oceania [38, 39] and Europe [30–37] and lower in Africa [15–17] and certain parts of Asia [21–29] (in China [22] and Iran [23] the total prevalence was less than 10% by the IOTF cut-offs). Overall, about 30% of American adolescents and 22%–25% of European adolescents (excepting the Czech Republic and Italian adolescents’ which showed a prevalence of 13.7% and 17.9%, resp.) were overweight or obese. Among Oceanian adolescents the prevalence ranged from 23.2% in Australia in 2004 to 34.2% in New Zealand in 2007. In Africa, the overall prevalence of overweight and obesity was lower than 20%. Among Asian adolescents there was a broad range of overweight plus obesity. Using IOTF cut-off, the prevalence of being overweight or obese for Asian boys and girls ranged from 5.2% in China in 2002 to 36.4% in Bahrain in 2000.Table3 shows regional data prevalence of overweight and obesity from fifteen countries. Specific prevalence from all the geographic regions was included in this review from three countries: South Africa (nine provinces) [15], USA (fifty two states) [20], and Italy (five regions) [34]. In Europe, data from islands of Greece (Crete) [46] and Italy (Sicily and Sardinia) [48, 49] and Spain (Balearic Islands’ archipelago [51]; and the Grand Canary Island [52]) were also included. On the other hand, regional but not national data was found for eleven countries (Italy [34], Brazil [40], India [42], Jordan [43], Denmark [44], France [45], Hungary [47], Poland [48], Spain [51, 52], Switzerland [53], and Turkey [54]). The IOTF cut-off was used to classify overweight and obesity in fourteen of the eighteen selected studies that included regional data. In one study [51], data was presented using only the WHO-2007 growth charts and in two studies using only the CDC-2000 growth reference [20, 43].Table 3
Description of overweight and obesity prevalence (%) along with total data by sex from each regional study that was included in the review according to year of survey, study population, age range, and classification criteria used.
Continent
Country, region
Date of survey
Study population
Age (years)
Criteria
Overweight (%)
Obesity (%)
Reference
All
Boys
Girls
All
Boys
Girls
Africa
South Africa, Eastern Cape
2008
2008 SA YRBS
13–19
IOTF1
13.3
4.3
21.1
4.0
2.0
5.6
Reddy et al., 2010 [15]
South Africa, Free State
2008
2008 SA YRBS
13–19
IOTF1
11.6
8.1
15.1
4.7
3.7
5.7
Reddy et al., 2010 [15]
South Africa, Gauteng
2008
2008 SA YRBS
13–19
IOTF1
12.7
10.0
15.4
9.7
8.4
11.0
Reddy et al., 2010 [15]
South Africa, KwaZulu-Natal
2008
2008 SA YRBS
13–19
IOTF1
20.1
8.6
31.5
5.4
3.4
7.3
Reddy et al., 2010 [15]
South Africa, Limpopo
2008
2008 SA YRBS
13–19
IOTF1
10.7
6.2
15.1
2.8
1.0
4.5
Reddy et al., 2010 [15]
South Africa, Mpumalanga
2008
2008 SA YRBS
13–19
IOTF1
15.5
10.0
21.1
6.1
2.3
9.9
Reddy et al., 2010 [15]
South Africa, Northern Cape
2008
2008 SA YRBS
13–19
IOTF1
12.9
7.3
18.3
5.0
4.4
5.6
Reddy et al., 2010 [15]
South Africa, North West
2008
2008 SA YRBS
13–19
IOTF1
11.8
7.0
16.7
3.9
2.2
5.7
Reddy et al., 2010 [15]
South Africa, Western Cape
2008
2008 SA YRBS
13–19
IOTF1
14.3
9.7
18.5
5.6
2.0
8.9
Reddy et al., 2010 [15]
America
USA, Alaska
2007
2007 NSCH
10–17
CDC-20002
19.8
22.7
16.7
14.1
14.6
13.7
Singh et al., 2010 [20]
USA, Alabama
2007
2007 NSCH
10–17
CDC-20002
18.2
17.6
18.9
17.9
24.4
10.9
Singh et al., 2010 [20]
USA, Arkansas
2007
2007 NSCH
10–17
CDC-20002
17.1
15.0
19.2
20.4
27.2
13.2
Singh et al., 2010 [20]
USA, Arizona
2007
2007 NSCH
10–17
CDC-20002
12.8
12.7
12.7
17.8
20.6
15.0
Singh et al., 2010 [20]
USA, California
2007
2007 NSCH
10–17
CDC-20002
15.5
13.4
17.5
15.0
17.4
12.8
Singh et al., 2010 [20]
USA, Colorado
2007
2007 NSCH
10–17
CDC-20002
13.0
17.5
8.5
14.2
17.5
10.7
Singh et al., 2010 [20]
USA, Connecticut
2007
2007 NSCH
10–17
CDC-20002
13.2
14.7
11.7
12.5
14.8
10.2
Singh et al., 2010 [20]
USA, Washington, DC
2007
2007 NSCH
10–17
CDC-20002
15.2
11.6
18.7
20.2
22.2
18.2
Singh et al., 2010 [20]
USA, Delaware
2007
2007 NSCH
10–17
CDC-20002
19.9
22.0
17.8
13.3
12.2
14.4
Singh et al., 2010 [20]
USA, Florida
2007
2007 NSCH
10–17
CDC-20002
14.8
12.7
17.1
18.3
21.5
15.0
Singh et al., 2010 [20]
USA, Georgia
2007
2007 NSCH
10–17
CDC-20002
16.0
14.4
17.7
21.3
24.7
17.7
Singh et al., 2010 [20]
USA, Hawaii
2007
2007 NSCH
10–17
CDC-20002
17.3
17.5
17.1
11.2
15.0
7.1
Singh et al., 2010 [20]
USA, Iowa
2007
2007 NSCH
10–17
CDC-20002
15.3
14.8
15.9
11.2
11.3
11.0
Singh et al., 2010 [20]
USA, Idaho
2007
2007 NSCH
10–17
CDC-20002
15.7
14.4
17.2
11.8
16.4
6.8
Singh et al., 2010 [20]
USA, Illinois
2007
2007 NSCH
10–17
CDC-20002
14.2
12.1
16.4
20.7
25.0
16.3
Singh et al., 2010 [20]
USA, Indiana
2007
2007 NSCH
10–17
CDC-20002
15.2
11.5
19.3
14.7
17.4
11.7
Singh et al., 2010 [20]
USA, Kansas
2007
2007 NSCH
10–17
CDC-20002
14.9
16.0
13.7
16.2
16.2
16.3
Singh et al., 2010 [20]
USA, Kentucky
2007
2007 NSCH
10–17
CDC-20002
16.1
17.7
14.6
21.0
22.5
19.4
Singh et al., 2010 [20]
USA, Louisiana
2007
2007 NSCH
10–17
CDC-20002
15.2
15.5
14.9
20.7
23.1
18.1
Singh et al., 2010 [20]
USA, Massachusetts
2007
2007 NSCH
10–17
CDC-20002
16.7
18.2
15.4
13.3
16.1
10.5
Singh et al., 2010 [20]
USA, Maryland
2007
2007 NSCH
10–17
CDC-20002
15.2
19.1
11.1
13.6
17.0
9.9
Singh et al., 2010 [20]
USA, Maine
2007
2007 NSCH
10–17
CDC-20002
15.3
15.6
14.9
12.9
16.0
9.8
Singh et al., 2010 [20]
USA, Michigan
2007
2007 NSCH
10–17
CDC-20002
18.1
20.4
15.8
12.5
14.3
10.5
Singh et al., 2010 [20]
USA, Minnesota
2007
2007 NSCH
10–17
CDC-20002
12.0
12.1
11.8
11.1
14.3
7.6
Singh et al., 2010 [20]
USA, Missouri
2007
2007 NSCH
10–17
CDC-20002
17.4
16.9
17.8
13.6
15.5
11.6
Singh et al., 2010 [20]
USA, Mississippi
2007
2007 NSCH
10–17
CDC-20002
22.6
21.6
23.5
21.9
25.5
18.5
Singh et al., 2010 [20]
USA, Montana
2007
2007 NSCH
10–17
CDC-20002
13.8
15.0
12.5
11.8
16.6
6.6
Singh et al., 2010 [20]
USA, North Carolina
2007
2007 NSCH
10–17
CDC-20002
14.9
13.9
16.0
18.6
19.3
17.9
Singh et al., 2010 [20]
USA, North Dakota
2007
2007 NSCH
10–17
CDC-20002
14.3
16.9
11.6
11.4
15.7
7.0
Singh et al., 2010 [20]
USA, Nebraska
2007
2007 NSCH
10–17
CDC-20002
15.7
13.9
17.5
15.8
23.0
8.1
Singh et al., 2010 [20]
USA, New Hampshire
2007
2007 NSCH
10–17
CDC-20002
16.6
17.1
16.2
12.8
16.3
8.8
Singh et al., 2010 [20]
USA, New Jersey
2007
2007 NSCH
10–17
CDC-20002
15.6
17.3
13.8
15.4
18.6
11.7
Singh et al., 2010 [20]
USA, New Mexico
2007
2007 NSCH
10–17
CDC-20002
16.7
15.3
18.1
16.0
20.4
11.4
Singh et al., 2010 [20]
USA, Nevada
2007
2007 NSCH
10–17
CDC-20002
19.0
21.9
16.0
15.2
19.4
10.8
Singh et al., 2010 [20]
USA, New York
2007
2007 NSCH
10–17
CDC-20002
15.8
15.1
16.5
17.1
20.3
13.8
Singh et al., 2010 [20]
USA, Ohio
2007
2007 NSCH
10–17
CDC-20002
14.8
18.7
10.9
18.5
22.9
14.2
Singh et al., 2010 [20]
USA, Oklahoma
2007
2007 NSCH
10–17
CDC-20002
13.2
18.1
8.2
16.4
17.4
15.4
Singh et al., 2010 [20]
USA, Oregon
2007
2007 NSCH
10–17
CDC-20002
14.7
16.2
13.3
9.6
11.0
8.2
Singh et al., 2010 [20]
USA, Pennsylvania
2007
2007 NSCH
10–17
CDC-20002
14.7
15.5
13.7
15.0
21.0
8.4
Singh et al., 2010 [20]
USA, Rhode Island
2007
2007 NSCH
10–17
CDC-20002
15.7
15.5
16.0
14.4
18.2
10.5
Singh et al., 2010 [20]
USA, South Carolina
2007
2007 NSCH
10–17
CDC-20002
18.5
20.8
15.9
15.3
18.4
12.0
Singh et al., 2010 [20]
USA, South Dakota
2007
2007 NSCH
10–17
CDC-20002
15.2
17.3
13.0
13.2
16.0
10.2
Singh et al., 2010 [20]
USA, Tennessee
2007
2007 NSCH
10–17
CDC-20002
15.9
14.5
17.3
20.6
23.3
17.9
Singh et al., 2010 [20]
USA, Texas
2007
2007 NSCH
10–17
CDC-20002
11.8
11.0
12.6
20.4
20.6
20.2
Singh et al., 2010 [20]
USA, Utah
2007
2007 NSCH
10–17
CDC-20002
11.7
12.1
11.2
11.4
14.7
7.9
Singh et al., 2010 [20]
USA, Virginia
2007
2007 NSCH
10–17
CDC-20002
15.8
16.1
15.4
15.2
16.6
13.9
Singh et al., 2010 [20]
USA, Vermont
2007
2007 NSCH
10–17
CDC-20002
13.8
16.4
11.1
12.9
17.0
8.4
Singh et al., 2010 [20]
USA, Washington
2007
2007 NSCH
10–17
CDC-20002
18.4
21.9
14.7
11.1
14.7
7.3
Singh et al., 2010 [20]
USA, Wisconsin
2007
2007 NSCH
10–17
CDC-20002
14.8
17.3
12.2
13.1
15.6
10.5
Singh et al., 2010 [20]
USA, West Virginia
2007
2007 NSCH
10–17
CDC-20002
16.6
16.9
16.4
18.9
21.8
15.7
Singh et al., 2010 [20]
USA, Wyoming
2007
2007 NSCH
10–17
CDC-20002
15.5
16.6
14.2
10.2
14.1
5.5
Singh et al., 2010 [20]
Brazil, Pernambuco State
2006
GSHS
14–19
IOTF1
11.5
11.3
11.6
2.4
2.0
2.8
Tassitano et al., 2009 [40]
Asia
China, Hong Kong
2003-04
School-based survey
11–18
IOTF1
7.1
9.6
4.9
2.8
3.9
1.8
Ko et al., 2008 [41]
CDC-20002
8.3
11.3
5.8
4.1
6.0
2.4
India, Manipur
2005-06
School-based survey
12–19
IOTF1
4.4
4.1
4.7
0.7
1.0
0.4
Bishwalata et al., 2010 [42]
Jordan, Irbid Governorate
2007
School-based survey
13–16
CDC-20002
15.7
11.8
18.9
8.7
12.3
5.8
Abu Baker and Daradkeh, 2010 [43]
Europe
Denmark, Greater Copenhagen area and 3 municipalities outside the Capital Region
2007–09
School-based survey
14–16
IOTF1
14.0
15.2
12.9
11.2
14.1
8.2
Søren and Jo, 2010 [44]
France, Aquitaine Region
2004-05
School-based survey
11–18
IOTF1
11.7
13.3
10.1
1.9
2.4
1.4
Thibault et al., 2010 [45]
Greece, Crete
2005-06
School-based survey
10–12
IOTF1
28.0
30.0
27.0
13.0
15.0
10.0
Manios et al., 2011 [46]
Hungary, Szeged and Szolnok regions
2005-06
School-based survey
11–16
IOTF1
16.8
17.9
15.7
6.6
7.9
5.2
Baráth et al., 2010 [47]
Italy, North-West
2002
HBSC Study
11, 13, 16
IOTF1
—
18.3
7.1
—
2.5
1.1
Vieno et al., 2005 [34]
Italy, North-East
2002
HBSC Study
11, 13, 16
IOTF1
—
16.5
11.7
—
0.8
1.5
Vieno et al., 2005 [34]
Italy, Center
2002
HBSC Study
11, 13, 16
IOTF1
—
20.7
11.2
—
3.9
2.5
Vieno et al., 2005 [34]
Italy, South
2002
HBSC Study
11, 13, 16
IOTF1
—
25.7
15.7
—
4.4
0.9
Vieno et al., 2005 [34]
Italy, Islands
2002
HBSC Study
11, 13, 16
IOTF1
—
31.3
10.4
—
7.6
0.8
Vieno et al., 2005 [34]
Italy, Sardinia
1999–2001
School-based survey
11–15
IOTF1
14.9
15.4
14.6
3.7
5.1
3.2
Velluzzi et al., 2007 [48]
Italy, Sicily
1999–2001
Public school-based survey
11–15
CDC-20002
18.3
18.8
17.8
11.8
15.1
8.5
Baratta et al., 2006 [49]
Poland, Kujawsko-Pomorskie
2005
School based survey
13–15
IOTF1
10.7
12.0
9.5
1.4
1.6
1.3
Jodkowska et al., 2010 [50]
Poland, Lubuskie
2005
School based survey
13–15
IOTF1
11.1
12.2
10.1
3.0
2.5
3.5
Jodkowska et al., 2010 [50]
Poland, Malapolskie
2005
School based survey
13–15
IOTF1
12.7
12.8
12.6
1.6
1.9
1.3
Jodkowska et al., 2010 [50]
Poland, Podlaskie
2005
School based survey
13–15
IOTF1
13.9
14.5
13.3
2.8
3.1
2.6
Jodkowska et al., 2010 [50]
Poland, Pomorskie
2005
School based survey
13–15
IOTF1
13.7
13.4
13.9
2.1
2.0
2.2
Jodkowska et al., 2010 [50]
Spain, Balearic Islands
2007-08
School-based survey
12–17
WHO-20073
17.5
19.9
15.5
10.4
12.7
8.5
Bibiloni et al., 2010 [51]
Spain, Grand Canary
2004-05
School-based survey
12–14
IOTF1
21.6
21.0
22.2
7.5
7.8
7.2
Henríquez Sánchez et al., 2008 [52]
Switzerland, Canton of Vaud
2005-06
Public school-based survey
10–14
IOTF1
12.0
13.2
10.7
1.7
1.8
1.7
Lasserre et al., 2007 [53]
CDC-20002
10.7
11.9
9.4
3.6
4.2
3.0
Turkey, Edirne Province
2001
Two school-based surveys
12–17
IOTF1
10.9
11.3
10.6
1.9
1.6
2.1
Öner et al., 2004 [54]
1Overweight and obesity, all adolescents with BMI-for-age ≥25 kg/m2 and <30 kg/m2 and ≥30 kg/m2, respectively, according to the IOTF [6].
2Overweight and obesity, all adolescents with BMI-for-age ≥P85th and <P95th and ≥P95th, respectively, according to the CDC [5].
3Overweight and obesity, all adolescents with BMI-for-age ≥P85th and <P95th and ≥P97th, respectively, according to the WHO [7].
IOTF: International Obesity Task Force; CDC: Center for Disease Control and Prevention; WHO: World Health Organization; 2008 SA YRBS: 2008 South African National Youth Risk Behaviour; 2007 NSCH: National Survey of Children’s Health; GSHS: Global School Based Student Health Survey; HBSC: Health Behaviour in School-aged Children.In South Africa and USA, substantial geographic variations in adolescent overweight and obesity existed. In 2008, overweight and obesity prevalence varied in South Africa from 13.5% in Limpopo to 25.5% in KwaZulu-Natal. In 2007, overweight and obesity varied in USA from 23.1% in Utah and Minnesota to 44.5% in Mississippi. In 2002, the prevalence of overweight and obesity in Southern Italy and Italian islands was higher among boys. In Southern Italy, the overweight prevalence among girls also was higher than in the other geographic regions.Comparison between the islands from Greece (Crete), Italy (Sicily and Sardinia), and Spain (Balearic Islands and Grand Canary Island) which were included in this review showed that Crete had the highest prevalence of overweight and obesity—despite data were presented using different definition. In Spain, using the IOTF cut-off (data not shown for Balearic Islands but given by authors), the prevalence of overweight plus obesity was higher in the Grand Canary Island (29.1%) than in the Balearic Islands (24.7%).


### 3.3. Gender Differences

According to national data, the prevalence of overweight among boys was ≥10% higher than girls in nine countries (Canada [18], Qatar [26], Taiwan [28], Cyprus [30], Czech Republic [31], Germany [32], Greece [33], Italy [34], Australia [38], Denmark [44], and Hungary [47]) and among girls ≥10% higher than boys in seven of the twenty-five countries (South Africa [15], Seychelles [16], Tunisia [17], Mexico [19], Bahrain [21], Saudi Arabia [27], and Sweden [37]). The obesity prevalence was ≥10% higher among boys in seventeen countries (Canada [18], USA [20], China [22], Iran [23], Israel [24], Qatar [26], Saudi Arabia [27], Taiwan [28], Cyprus [30], Czech Republic [31], Germany [32], Greece [33], Italy [34], Portugal [36], Sweden [37], Australia [38], New Zealand [39], Denmark [44], and Hungary [47]) and ≥10% higher among girls in four of the twenty-five countries (South Africa [14], Seychelles [16], Tunisia [17], and Bahrain [21]).


## 3.1. Literature Search

A total of thirty-nine articles and a National Health Report were eligible according to the inclusion criteria established for this review. Table1 presents a description of the forty studies selected for this review including the continent and the country where it was performed (and region for not national studies), year of publishing, total number of participants in the study, number of adolescents, age range, proportion of girls, and number and definition for overweight and obesity classification used. All the articles were published after the year of 2002. Nationally representative data were obtained in twenty-five countries (including Northern Ireland) [15–39], and ten countries were represented only by regional data [40, 42, 44, 45, 47, 50–54].Table 1
Descriptive analysis of the studies reviewed.
Area
Continent
Country, region
Date of survey
Totaln of study1
Totaln of adolescents1
Age (years)/school grade
Proportion of girls
Number of definition
Definition
Reference
National
Africa
Seychelles
2004
4,854
2,177
7th, 10th
51.5%
1
IOTF
Bovet et al., 2006 [16]
South Africa
2008
9,862
9,862
13–19
50.9%
1
IOTF
Reddy et al., 2010 [15]
Tunisia
2004
2,872
2,872
15–19
54.9%
1
IOTF
Aounallah-Skhiri et al., 2008 [17]
America
Canada
2004
8,661
4,099
12–17
—
3
IOTF, CDC, WHO
Shields and Tremblay, 2010 [18]
Mexico
2006
48,304
13,219
12–18
50.7%
1
IOTF
Bonvecchio et al., 2009 [19]
USA
2007
44,101
44,101
10–17
—
1
CDC
Singh et al., 2010 [20]
Asia
Bahrain
2000
506
506
12–17
50.8%
1
IOTF
Al-Sendi et al., 2003 [21]
China
2002
44,880
12,475
13–17
47.7%
1
IOTF
Li et al., 2008 [22]
Iran
2003-04
21,111
16,035
10–18
51.3%
2
IOTF, CDC
Kelishadi et al., 2008 [23]
Israel
2003-04
5,588
5,588
11–19
55.1%
1
CDC
Nitzan Kaluski et al., 2009 [24]
Jordan
2009
5,640
637
13–18
55.7%
1
IOTF
Khader et al., 2011 [25]
Qatar
2003-04
3,923
3,923
12–17
49.8%
1
IOTF
Bener, 2006 [26]
Saudi Arabia
2005
19,317
7,251
13–18
49.2%
2
CDC, WHO
El Mouzan et al., 2010 [27]
Taiwan
2003
72,789
58,424
10–18
49.0%
1
IOTF
Liou et al., 2009 [28]
United Arab Emirates
2009-10
1,007
276
11–18
—
1
IOTF
Ng et al., 2011 [29]
Europe
Cyprus
1999-2000
2,467
1,694
10–17
50.7%
1
IOTF
Savva et al., 2002 [30]
Czech Republic
2005
1,417
957
11–17
49.4%
1
IOTF
Kunesova et al., 2007 [31]
Germany
2008
40,622
5,623
12–16
46.7%
1
IOTF
Blüher et al., 2011 [32]
Greece
2003
14,456
14,456
13–19
53.8%
1
IOTF
Tzotzas et al., 2008 [33]
Italy
2002
4,386
4,386
11, 13, 15
51.6%
1
IOTF
Vieno et al., 2005 [34]
Republic of Ireland
2003
17,499
7,294
11–16
50.6%
1
IOTF
Whelton et al., 2007 [35]
Northern Ireland
2003
2,039
964
11–15
51.5%
1
IOTF
Whelton et al., 2007 [35]
Portugal
2008
22,048
22,048
10–18
51.5%
2
IOTF, WHO
Sardinha et al., 2011 [36]
Sweden
2001
1,732
1,732
10, 13, 16
48.3%
1
IOTF
Ekblom et al., 2004 [37]
Oceania
Australia
2004
5,407
1,771
8th, 10th
45.6%
1
IOTF
Booth et al., 2007 [38]
New Zealand
2007
8,796
8,796
13–17
45.4%
2
IOTF, WHO
Utter et al., 2010 [39]
Regional
Africa
South Africa, Eastern Cape
2008
926
926
13–19
52.1%
1
IOTF
Reddy et al., 2010 [15]
South Africa, Free State
2008
1,236
1,236
13–19
49.1%
1
IOTF
Reddy et al., 2010 [15]
South Africa, Gauteng
2008
931
931
13–19
52.1%
1
IOTF
Reddy et al., 2010 [15]
South Africa, KwaZulu-Natal
2008
910
910
13–19
52.1%
1
IOTF
Reddy et al., 2010 [15]
South Africa, Limpopo
2008
1,140
1,140
13–19
50.5%
1
IOTF
Reddy et al., 2010 [15]
South Africa, Mpumalanga
2008
1,238
1,238
13–19
49.8%
1
IOTF
Reddy et al., 2010 [15]
South Africa, Northern Cape
2008
1,088
1,088
13–19
48.6%
1
IOTF
Reddy et al., 2010 [15]
South Africa, North West
2008
1,234
1,234
13–19
48.6%
1
IOTF
Reddy et al., 2010 [15]
South Africa, Western Cape
2008
1,159
1,159
13–19
56.4%
1
IOTF
Reddy et al., 2010 [15]
America
USA, 52 Sates2
2007
—
—
10–17
—
1
CDC
Singh et al., 2010 [20]
Brazil, Pernambuco State
2006
4,210
4,210
14–19
59.8%
1
IOTF
Tassitano et al., 2009 [40]
Asia
China, Hong Kong
2003-04
2,098
2,098
11–18
53.2%
2
IOTF, CDC
Ko et al., 2008 [41]
India, Manipur
2005-06
3,356
3,356
12–19
56.2%
1
IOTF
Bishwalata et al., 2010 [42]
Jordan, Irbid Governorate
2007
1,355
1,355
13–16
55.6%
1
CDC
Abu Baker and Daradkeh, 2010 [43]
Europe
Denmark, Greater Copenhagen area and 3 municipalities outside the Capital Region
2007–09
7,541
7,541
14–16
50.1%
1
IOTF
Søren and Jo, 2010 [44]
France, Aquitaine Region
2004-05
2,385
2,385
11–18
49.1%
1
IOTF
Thibault et al., 2010 [45]
Greece, Crete
2005-06
481
481
10–12
54.0%
1
IOTF
Manios et al., 2011 [46]
Hungary, Szeged and Szolnok regions
2005-2006
14,290
14,290
11–16
48.1%
1
IOTF
Baráth et al., 2010 [47]
Italy, 5 residence regions3
2002
4,386
4,386
11–15
51.6%
1
IOTF
Vieno et al., 2005 [34]
Italy, Sardinia
1999–2001
3,946
3,946
11–15
49.0%
1
IOTF
Velluzzi et al., 2007 [48]
Italy, Sicily
1999–2001
48,897
48,897
11–15
50.7%
1
CDC
Baratta et al., 2006 [49]
Poland, Kujawsko-Pomorskie
2005
—
—
13–15
—
1
IOTF
Jodkowska et al., 2010 [50]
Poland, Lubuskie
2005
—
—
13–15
—
1
IOTF
Jodkowska et al., 2010 [50]
Poland, Malapolskie
2005
—
—
13–15
—
1
IOTF
Jodkowska et al., 2010 [50]
Poland, Podlaskie
2005
—
—
13–15
—
1
IOTF
Jodkowska et al., 2010 [50]
Poland, Pomorskie
2005
—
—
13–15
—
1
IOTF
Jodkowska et al., 2010 [50]
Spain, Balearic Islands
2007-08
1,231
1,231
12–17
53.4%
1
WHO
Bibiloni et al., 2010 [51]
Spain, Grand Canary
2004-05
1,002
1,002
12–14
50.0%
1
IOTF
Henríquez Sánchez et al., 2008 [52]
Switzerland, Canton of Vaud
2005-06
5,207
5,207
10–14
49.7%
2
IOTF, CDC
Lasserre et al., 2007 [53]
Turkey, Edirne Province
2001
989
989
12–17
48.1%
1
IOTF
Öner et al., 2004 [54]
1Only subjects with anthropometric measurements were included in each country.
2There are 52 states in the USA, but no information about total number of subjects was included in each state.
3Vieno et al. [34] assessed the overall overweight and obesity prevalence among Italian adolescents, and also according to the geographic region: North-West, North-East, Center, South, and Islands, but no information about total number of subjects was included in each region.
IOTF: International Obesity Task Force; CDC: Center for Disease Control and Prevention; WHO: World Health Organization.


## 3.2. Prevalence and Criteria for Classification

Table2 shows overweight and obesity prevalence from the twenty-five national studies (one of them including data from Northern Ireland) that were included in this review according to the continent and the country where it was performed, year of survey, study population, age range, criteria used for classifying overweight and obesity used, and along with total data by sex. There were thirty-two different prevalence levels described in the included articles, because five countries presented data using at least two different criteria for overweight and obesity classification [18, 23, 27, 36, 39]. The IOTF cut-off was used to classify overweight and obesity in twenty-three of the twenty-five national studies considered in the present review.Table 2
Description of overweight and obesity prevalence (%) along with total data by sex from each national study that was included in the review according to year of survey, study population, age range, and classification criteria used.
Continent
Country
Date of survey
Study population
Age (years)/school grade
Criteria
Overweight (%)
Obesity (%)
Reference
All
Boys
Girls
All
Boys
Girls
Africa
Seychelles
2004
School-based survey
7th, 10th
IOTF1
12.0
9.5
14.3
5.1
4.2
6.0
Bovet et al., 2006 [16]
South Africa
2008
2008 SA YRBS
13–19
IOTF1
14.4
7.9
20.6
5.3
3.3
7.2
Reddy et al., 2010  [15]
Tunisia
2004
Household-based survey
15–19
IOTF1
12.4
11.0
14.1
2.6
1.9
3.2
Aounallah-Skhiri et al., 2008 [17]
America
Canada
2004
2004 CCHS
12–17
IOTF1
19.8
21.2
18.4
9.4
11.1
7.4
Shields and Tremblay, 2010 [18]
CDC-20002
15.9
17.0
14.7
12.1
14.3
9.6
WHO-20073
20.8
21.9
19.6
12.4
15.1
9.4
Mexico
2006
Household-based survey
12–18
IOTF1
21.2
20.1
22.3
8.9
9.2
8.6
Bonvecchio et al., 2009 [19]
USA
2007
2007 NSCH
10–17
CDC-20002
15.2
15.3
15.2
16.4
19.2
13.5
Singh et al., 2010 [20]
Asia
Bahrain
2000
School-based survey
12–17
IOTF1
20.0
15.3
24.5
16.4
14.9
17.9
Al-Sendi et al., 2003  [21]
China
2002
2002 CNNHS
13–17
IOTF1
4.6
4.6
4.6
0.6
0.7
0.5
Li et al., 2008  [22]
Iran
2003-04
CASPIAN Study
10–18
IOTF1
5.9
5.7
6.0
1.3
1.5
1.1
Kelishadi et al., 2008 [23]
CDC-20002
4.5
4.3
4.7
1.9
2.3
1.6
Israel
2003-04
MABAT Youth Survey
11–19
CDC-20002
12.9
12.7
13.0
5.6
7.4
4.1
Nitzan Kaluski et al., 2009 [24]
Jordan
2009
Household-based survey
13–18
IOTF1
13.7
11.3
15.5
10.0
12.4
8.2
Khader et al., 2011 [25]
Qatar
2003-04
School-based survey
12–17
IOTF1
23.8
28.6
18.9
6.3
7.9
4.7
Bener, 2006 [26]
Saudi Arabia
2005
Household-based survey
13–18
CDC-20002
17.9
16.5
19.6
7.0
8.2
5.5
El Mouzan et al., 2010 [27]
WHO-20073
16.0
13.6
18.4
10.6
11.2
10.0
Taiwan
2003
School-based survey
10–18
IOTF1
16.3
18.4
14.2
6.2
8.1
4.2
Liou et al., 2009 [28]
United Arab Emirates
2009-10
Household-based survey
11–18
IOTF1
—
16.2
20.5
—
11.7
19.7
Ng et al., 2011 [29]
Europe
Cyprus
1999-00
School-based survey
10–17
IOTF1
18.9
21.3
16.5
5.8
7.1
4.5
Savva et al., 2002 [30]
Czech Republic
2005
Lifestyle and Obesity Study
6–17
IOTF1
12.3
16.6
8.0
1.4
1.7
1.0
Kunesova et al., 2007 [31]
Germany
2008
CrescNet database
12–16
IOTF1
18.2
19.3
17.0
6.2
7.6
4.6
Blüher et al., 2011 [32]
Greece
2003
School-based survey
13–19
IOTF1
18.3
23.3
14.0
4.3
6.1
2.7
Tzotzas et al., 2008 [33]
Italy
2002
HBSC Study
11, 13, 15
IOTF1
15.6
20.9
10.6
2.3
3.5
1.2
Vieno et al., 2005 [34]
Republic of Ireland
2003
School-based survey
11–16
IOTF1
18.5
17.8
19.2
5.8
5.6
6.1
Whelton et al., 2007 [35]
Northern Ireland
2003
School-based survey
11–15
IOTF1
18.2
18.5
17.8
5.9
6.0
5.7
Whelton et al., 2007 [35]
Portugal
2008
School-based survey
10–18
IOTF1
17.4
17.7
17.0
5.2
5.8
4.6
Sardinha et al., 2011 [36]
WHO-2007
21.8
20.4
23.1
9.9
10.3
9.6
Sweden
2001
School-based survey
10, 13, 16
IOTF1
15.8
14.6
16.9
4.4
5.0
3.6
Ekblom et al., 2004 [37]
Oceania
Australia
2004
2004 SPANS
8th, 10th
IOTF1
17.9
19.4
16.2
5.3
6.7
3.6
Booth et al., 2007 [38]
New Zealand
2007
Youth’07 Survey
13–17
IOTF1
24.0
23.3
24.7
10.2
10.8
9.5
Utter et al., 2010 [39]
WHO-2007
25.9
25.9
26.0
13.5
14.6
12.1
1Overweight and obesity, all adolescents with BMI-for-age ≥25 kg/m2 and <30 kg/m2 and ≥30 kg/m2, respectively, according to the IOTF [6].
2Overweight and obesity, all adolescents with BMI-for-age ≥P85th and <P95th and ≥P95th, respectively, according to the CDC [5].
3Overweight and obesity, all adolescents with BMI-for-age >+1SD and <+2SD and >+2SD, respectively, according to the WHO [7].
IOTF: International Obesity Task Force; CDC: Center for Disease Control and Prevention; WHO: World Health Organization; 2008 SA YRBS: 2008 South African National Youth Risk Behaviour; 2004 CCHS: 2004 Canadian Community Health Survey; 2007 NSCH: National Survey of Children’s Health; 2002 CNNHS: 2002 China National Nutrition and Health Survey; CASPIAN Study: Childhood and Adolescence Surveillance and Prevention of Adult Non-communicable disease; HBSC: Health Behaviour in School-aged Children; 2004 SPANS: 2004 NSW Schools Physical Activity and Nutrition Survey.There was a broad range of overweight and obesity prevalence noted. In general, the prevalence of overweight plus obesity was higher in America [18–20], Oceania [38, 39] and Europe [30–37] and lower in Africa [15–17] and certain parts of Asia [21–29] (in China [22] and Iran [23] the total prevalence was less than 10% by the IOTF cut-offs). Overall, about 30% of American adolescents and 22%–25% of European adolescents (excepting the Czech Republic and Italian adolescents’ which showed a prevalence of 13.7% and 17.9%, resp.) were overweight or obese. Among Oceanian adolescents the prevalence ranged from 23.2% in Australia in 2004 to 34.2% in New Zealand in 2007. In Africa, the overall prevalence of overweight and obesity was lower than 20%. Among Asian adolescents there was a broad range of overweight plus obesity. Using IOTF cut-off, the prevalence of being overweight or obese for Asian boys and girls ranged from 5.2% in China in 2002 to 36.4% in Bahrain in 2000.Table3 shows regional data prevalence of overweight and obesity from fifteen countries. Specific prevalence from all the geographic regions was included in this review from three countries: South Africa (nine provinces) [15], USA (fifty two states) [20], and Italy (five regions) [34]. In Europe, data from islands of Greece (Crete) [46] and Italy (Sicily and Sardinia) [48, 49] and Spain (Balearic Islands’ archipelago [51]; and the Grand Canary Island [52]) were also included. On the other hand, regional but not national data was found for eleven countries (Italy [34], Brazil [40], India [42], Jordan [43], Denmark [44], France [45], Hungary [47], Poland [48], Spain [51, 52], Switzerland [53], and Turkey [54]). The IOTF cut-off was used to classify overweight and obesity in fourteen of the eighteen selected studies that included regional data. In one study [51], data was presented using only the WHO-2007 growth charts and in two studies using only the CDC-2000 growth reference [20, 43].Table 3
Description of overweight and obesity prevalence (%) along with total data by sex from each regional study that was included in the review according to year of survey, study population, age range, and classification criteria used.
Continent
Country, region
Date of survey
Study population
Age (years)
Criteria
Overweight (%)
Obesity (%)
Reference
All
Boys
Girls
All
Boys
Girls
Africa
South Africa, Eastern Cape
2008
2008 SA YRBS
13–19
IOTF1
13.3
4.3
21.1
4.0
2.0
5.6
Reddy et al., 2010 [15]
South Africa, Free State
2008
2008 SA YRBS
13–19
IOTF1
11.6
8.1
15.1
4.7
3.7
5.7
Reddy et al., 2010 [15]
South Africa, Gauteng
2008
2008 SA YRBS
13–19
IOTF1
12.7
10.0
15.4
9.7
8.4
11.0
Reddy et al., 2010 [15]
South Africa, KwaZulu-Natal
2008
2008 SA YRBS
13–19
IOTF1
20.1
8.6
31.5
5.4
3.4
7.3
Reddy et al., 2010 [15]
South Africa, Limpopo
2008
2008 SA YRBS
13–19
IOTF1
10.7
6.2
15.1
2.8
1.0
4.5
Reddy et al., 2010 [15]
South Africa, Mpumalanga
2008
2008 SA YRBS
13–19
IOTF1
15.5
10.0
21.1
6.1
2.3
9.9
Reddy et al., 2010 [15]
South Africa, Northern Cape
2008
2008 SA YRBS
13–19
IOTF1
12.9
7.3
18.3
5.0
4.4
5.6
Reddy et al., 2010 [15]
South Africa, North West
2008
2008 SA YRBS
13–19
IOTF1
11.8
7.0
16.7
3.9
2.2
5.7
Reddy et al., 2010 [15]
South Africa, Western Cape
2008
2008 SA YRBS
13–19
IOTF1
14.3
9.7
18.5
5.6
2.0
8.9
Reddy et al., 2010 [15]
America
USA, Alaska
2007
2007 NSCH
10–17
CDC-20002
19.8
22.7
16.7
14.1
14.6
13.7
Singh et al., 2010 [20]
USA, Alabama
2007
2007 NSCH
10–17
CDC-20002
18.2
17.6
18.9
17.9
24.4
10.9
Singh et al., 2010 [20]
USA, Arkansas
2007
2007 NSCH
10–17
CDC-20002
17.1
15.0
19.2
20.4
27.2
13.2
Singh et al., 2010 [20]
USA, Arizona
2007
2007 NSCH
10–17
CDC-20002
12.8
12.7
12.7
17.8
20.6
15.0
Singh et al., 2010 [20]
USA, California
2007
2007 NSCH
10–17
CDC-20002
15.5
13.4
17.5
15.0
17.4
12.8
Singh et al., 2010 [20]
USA, Colorado
2007
2007 NSCH
10–17
CDC-20002
13.0
17.5
8.5
14.2
17.5
10.7
Singh et al., 2010 [20]
USA, Connecticut
2007
2007 NSCH
10–17
CDC-20002
13.2
14.7
11.7
12.5
14.8
10.2
Singh et al., 2010 [20]
USA, Washington, DC
2007
2007 NSCH
10–17
CDC-20002
15.2
11.6
18.7
20.2
22.2
18.2
Singh et al., 2010 [20]
USA, Delaware
2007
2007 NSCH
10–17
CDC-20002
19.9
22.0
17.8
13.3
12.2
14.4
Singh et al., 2010 [20]
USA, Florida
2007
2007 NSCH
10–17
CDC-20002
14.8
12.7
17.1
18.3
21.5
15.0
Singh et al., 2010 [20]
USA, Georgia
2007
2007 NSCH
10–17
CDC-20002
16.0
14.4
17.7
21.3
24.7
17.7
Singh et al., 2010 [20]
USA, Hawaii
2007
2007 NSCH
10–17
CDC-20002
17.3
17.5
17.1
11.2
15.0
7.1
Singh et al., 2010 [20]
USA, Iowa
2007
2007 NSCH
10–17
CDC-20002
15.3
14.8
15.9
11.2
11.3
11.0
Singh et al., 2010 [20]
USA, Idaho
2007
2007 NSCH
10–17
CDC-20002
15.7
14.4
17.2
11.8
16.4
6.8
Singh et al., 2010 [20]
USA, Illinois
2007
2007 NSCH
10–17
CDC-20002
14.2
12.1
16.4
20.7
25.0
16.3
Singh et al., 2010 [20]
USA, Indiana
2007
2007 NSCH
10–17
CDC-20002
15.2
11.5
19.3
14.7
17.4
11.7
Singh et al., 2010 [20]
USA, Kansas
2007
2007 NSCH
10–17
CDC-20002
14.9
16.0
13.7
16.2
16.2
16.3
Singh et al., 2010 [20]
USA, Kentucky
2007
2007 NSCH
10–17
CDC-20002
16.1
17.7
14.6
21.0
22.5
19.4
Singh et al., 2010 [20]
USA, Louisiana
2007
2007 NSCH
10–17
CDC-20002
15.2
15.5
14.9
20.7
23.1
18.1
Singh et al., 2010 [20]
USA, Massachusetts
2007
2007 NSCH
10–17
CDC-20002
16.7
18.2
15.4
13.3
16.1
10.5
Singh et al., 2010 [20]
USA, Maryland
2007
2007 NSCH
10–17
CDC-20002
15.2
19.1
11.1
13.6
17.0
9.9
Singh et al., 2010 [20]
USA, Maine
2007
2007 NSCH
10–17
CDC-20002
15.3
15.6
14.9
12.9
16.0
9.8
Singh et al., 2010 [20]
USA, Michigan
2007
2007 NSCH
10–17
CDC-20002
18.1
20.4
15.8
12.5
14.3
10.5
Singh et al., 2010 [20]
USA, Minnesota
2007
2007 NSCH
10–17
CDC-20002
12.0
12.1
11.8
11.1
14.3
7.6
Singh et al., 2010 [20]
USA, Missouri
2007
2007 NSCH
10–17
CDC-20002
17.4
16.9
17.8
13.6
15.5
11.6
Singh et al., 2010 [20]
USA, Mississippi
2007
2007 NSCH
10–17
CDC-20002
22.6
21.6
23.5
21.9
25.5
18.5
Singh et al., 2010 [20]
USA, Montana
2007
2007 NSCH
10–17
CDC-20002
13.8
15.0
12.5
11.8
16.6
6.6
Singh et al., 2010 [20]
USA, North Carolina
2007
2007 NSCH
10–17
CDC-20002
14.9
13.9
16.0
18.6
19.3
17.9
Singh et al., 2010 [20]
USA, North Dakota
2007
2007 NSCH
10–17
CDC-20002
14.3
16.9
11.6
11.4
15.7
7.0
Singh et al., 2010 [20]
USA, Nebraska
2007
2007 NSCH
10–17
CDC-20002
15.7
13.9
17.5
15.8
23.0
8.1
Singh et al., 2010 [20]
USA, New Hampshire
2007
2007 NSCH
10–17
CDC-20002
16.6
17.1
16.2
12.8
16.3
8.8
Singh et al., 2010 [20]
USA, New Jersey
2007
2007 NSCH
10–17
CDC-20002
15.6
17.3
13.8
15.4
18.6
11.7
Singh et al., 2010 [20]
USA, New Mexico
2007
2007 NSCH
10–17
CDC-20002
16.7
15.3
18.1
16.0
20.4
11.4
Singh et al., 2010 [20]
USA, Nevada
2007
2007 NSCH
10–17
CDC-20002
19.0
21.9
16.0
15.2
19.4
10.8
Singh et al., 2010 [20]
USA, New York
2007
2007 NSCH
10–17
CDC-20002
15.8
15.1
16.5
17.1
20.3
13.8
Singh et al., 2010 [20]
USA, Ohio
2007
2007 NSCH
10–17
CDC-20002
14.8
18.7
10.9
18.5
22.9
14.2
Singh et al., 2010 [20]
USA, Oklahoma
2007
2007 NSCH
10–17
CDC-20002
13.2
18.1
8.2
16.4
17.4
15.4
Singh et al., 2010 [20]
USA, Oregon
2007
2007 NSCH
10–17
CDC-20002
14.7
16.2
13.3
9.6
11.0
8.2
Singh et al., 2010 [20]
USA, Pennsylvania
2007
2007 NSCH
10–17
CDC-20002
14.7
15.5
13.7
15.0
21.0
8.4
Singh et al., 2010 [20]
USA, Rhode Island
2007
2007 NSCH
10–17
CDC-20002
15.7
15.5
16.0
14.4
18.2
10.5
Singh et al., 2010 [20]
USA, South Carolina
2007
2007 NSCH
10–17
CDC-20002
18.5
20.8
15.9
15.3
18.4
12.0
Singh et al., 2010 [20]
USA, South Dakota
2007
2007 NSCH
10–17
CDC-20002
15.2
17.3
13.0
13.2
16.0
10.2
Singh et al., 2010 [20]
USA, Tennessee
2007
2007 NSCH
10–17
CDC-20002
15.9
14.5
17.3
20.6
23.3
17.9
Singh et al., 2010 [20]
USA, Texas
2007
2007 NSCH
10–17
CDC-20002
11.8
11.0
12.6
20.4
20.6
20.2
Singh et al., 2010 [20]
USA, Utah
2007
2007 NSCH
10–17
CDC-20002
11.7
12.1
11.2
11.4
14.7
7.9
Singh et al., 2010 [20]
USA, Virginia
2007
2007 NSCH
10–17
CDC-20002
15.8
16.1
15.4
15.2
16.6
13.9
Singh et al., 2010 [20]
USA, Vermont
2007
2007 NSCH
10–17
CDC-20002
13.8
16.4
11.1
12.9
17.0
8.4
Singh et al., 2010 [20]
USA, Washington
2007
2007 NSCH
10–17
CDC-20002
18.4
21.9
14.7
11.1
14.7
7.3
Singh et al., 2010 [20]
USA, Wisconsin
2007
2007 NSCH
10–17
CDC-20002
14.8
17.3
12.2
13.1
15.6
10.5
Singh et al., 2010 [20]
USA, West Virginia
2007
2007 NSCH
10–17
CDC-20002
16.6
16.9
16.4
18.9
21.8
15.7
Singh et al., 2010 [20]
USA, Wyoming
2007
2007 NSCH
10–17
CDC-20002
15.5
16.6
14.2
10.2
14.1
5.5
Singh et al., 2010 [20]
Brazil, Pernambuco State
2006
GSHS
14–19
IOTF1
11.5
11.3
11.6
2.4
2.0
2.8
Tassitano et al., 2009 [40]
Asia
China, Hong Kong
2003-04
School-based survey
11–18
IOTF1
7.1
9.6
4.9
2.8
3.9
1.8
Ko et al., 2008 [41]
CDC-20002
8.3
11.3
5.8
4.1
6.0
2.4
India, Manipur
2005-06
School-based survey
12–19
IOTF1
4.4
4.1
4.7
0.7
1.0
0.4
Bishwalata et al., 2010 [42]
Jordan, Irbid Governorate
2007
School-based survey
13–16
CDC-20002
15.7
11.8
18.9
8.7
12.3
5.8
Abu Baker and Daradkeh, 2010 [43]
Europe
Denmark, Greater Copenhagen area and 3 municipalities outside the Capital Region
2007–09
School-based survey
14–16
IOTF1
14.0
15.2
12.9
11.2
14.1
8.2
Søren and Jo, 2010 [44]
France, Aquitaine Region
2004-05
School-based survey
11–18
IOTF1
11.7
13.3
10.1
1.9
2.4
1.4
Thibault et al., 2010 [45]
Greece, Crete
2005-06
School-based survey
10–12
IOTF1
28.0
30.0
27.0
13.0
15.0
10.0
Manios et al., 2011 [46]
Hungary, Szeged and Szolnok regions
2005-06
School-based survey
11–16
IOTF1
16.8
17.9
15.7
6.6
7.9
5.2
Baráth et al., 2010 [47]
Italy, North-West
2002
HBSC Study
11, 13, 16
IOTF1
—
18.3
7.1
—
2.5
1.1
Vieno et al., 2005 [34]
Italy, North-East
2002
HBSC Study
11, 13, 16
IOTF1
—
16.5
11.7
—
0.8
1.5
Vieno et al., 2005 [34]
Italy, Center
2002
HBSC Study
11, 13, 16
IOTF1
—
20.7
11.2
—
3.9
2.5
Vieno et al., 2005 [34]
Italy, South
2002
HBSC Study
11, 13, 16
IOTF1
—
25.7
15.7
—
4.4
0.9
Vieno et al., 2005 [34]
Italy, Islands
2002
HBSC Study
11, 13, 16
IOTF1
—
31.3
10.4
—
7.6
0.8
Vieno et al., 2005 [34]
Italy, Sardinia
1999–2001
School-based survey
11–15
IOTF1
14.9
15.4
14.6
3.7
5.1
3.2
Velluzzi et al., 2007 [48]
Italy, Sicily
1999–2001
Public school-based survey
11–15
CDC-20002
18.3
18.8
17.8
11.8
15.1
8.5
Baratta et al., 2006 [49]
Poland, Kujawsko-Pomorskie
2005
School based survey
13–15
IOTF1
10.7
12.0
9.5
1.4
1.6
1.3
Jodkowska et al., 2010 [50]
Poland, Lubuskie
2005
School based survey
13–15
IOTF1
11.1
12.2
10.1
3.0
2.5
3.5
Jodkowska et al., 2010 [50]
Poland, Malapolskie
2005
School based survey
13–15
IOTF1
12.7
12.8
12.6
1.6
1.9
1.3
Jodkowska et al., 2010 [50]
Poland, Podlaskie
2005
School based survey
13–15
IOTF1
13.9
14.5
13.3
2.8
3.1
2.6
Jodkowska et al., 2010 [50]
Poland, Pomorskie
2005
School based survey
13–15
IOTF1
13.7
13.4
13.9
2.1
2.0
2.2
Jodkowska et al., 2010 [50]
Spain, Balearic Islands
2007-08
School-based survey
12–17
WHO-20073
17.5
19.9
15.5
10.4
12.7
8.5
Bibiloni et al., 2010 [51]
Spain, Grand Canary
2004-05
School-based survey
12–14
IOTF1
21.6
21.0
22.2
7.5
7.8
7.2
Henríquez Sánchez et al., 2008 [52]
Switzerland, Canton of Vaud
2005-06
Public school-based survey
10–14
IOTF1
12.0
13.2
10.7
1.7
1.8
1.7
Lasserre et al., 2007 [53]
CDC-20002
10.7
11.9
9.4
3.6
4.2
3.0
Turkey, Edirne Province
2001
Two school-based surveys
12–17
IOTF1
10.9
11.3
10.6
1.9
1.6
2.1
Öner et al., 2004 [54]
1Overweight and obesity, all adolescents with BMI-for-age ≥25 kg/m2 and <30 kg/m2 and ≥30 kg/m2, respectively, according to the IOTF [6].
2Overweight and obesity, all adolescents with BMI-for-age ≥P85th and <P95th and ≥P95th, respectively, according to the CDC [5].
3Overweight and obesity, all adolescents with BMI-for-age ≥P85th and <P95th and ≥P97th, respectively, according to the WHO [7].
IOTF: International Obesity Task Force; CDC: Center for Disease Control and Prevention; WHO: World Health Organization; 2008 SA YRBS: 2008 South African National Youth Risk Behaviour; 2007 NSCH: National Survey of Children’s Health; GSHS: Global School Based Student Health Survey; HBSC: Health Behaviour in School-aged Children.In South Africa and USA, substantial geographic variations in adolescent overweight and obesity existed. In 2008, overweight and obesity prevalence varied in South Africa from 13.5% in Limpopo to 25.5% in KwaZulu-Natal. In 2007, overweight and obesity varied in USA from 23.1% in Utah and Minnesota to 44.5% in Mississippi. In 2002, the prevalence of overweight and obesity in Southern Italy and Italian islands was higher among boys. In Southern Italy, the overweight prevalence among girls also was higher than in the other geographic regions.Comparison between the islands from Greece (Crete), Italy (Sicily and Sardinia), and Spain (Balearic Islands and Grand Canary Island) which were included in this review showed that Crete had the highest prevalence of overweight and obesity—despite data were presented using different definition. In Spain, using the IOTF cut-off (data not shown for Balearic Islands but given by authors), the prevalence of overweight plus obesity was higher in the Grand Canary Island (29.1%) than in the Balearic Islands (24.7%).


## 3.3. Gender Differences

According to national data, the prevalence of overweight among boys was ≥10% higher than girls in nine countries (Canada [18], Qatar [26], Taiwan [28], Cyprus [30], Czech Republic [31], Germany [32], Greece [33], Italy [34], Australia [38], Denmark [44], and Hungary [47]) and among girls ≥10% higher than boys in seven of the twenty-five countries (South Africa [15], Seychelles [16], Tunisia [17], Mexico [19], Bahrain [21], Saudi Arabia [27], and Sweden [37]). The obesity prevalence was ≥10% higher among boys in seventeen countries (Canada [18], USA [20], China [22], Iran [23], Israel [24], Qatar [26], Saudi Arabia [27], Taiwan [28], Cyprus [30], Czech Republic [31], Germany [32], Greece [33], Italy [34], Portugal [36], Sweden [37], Australia [38], New Zealand [39], Denmark [44], and Hungary [47]) and ≥10% higher among girls in four of the twenty-five countries (South Africa [14], Seychelles [16], Tunisia [17], and Bahrain [21]).


## 4. Discussion

The aim of this study was to review systematically the literature on overweight and obesity prevalence among adolescents worldwide. Thirty-nine articles and one National Health Report that met the inclusion criteria were considered. The overweight and obesity prevalence in the included studies ranged widely. In sixteen of the twenty-three countries with national representative data using the IOTF cut-off, overweight and obesity prevalence higher than 20% were found, five countries showed prevalence above 30%, and just in two countries prevalence was lower than 10%.Regarding national data, when prevalence was analysed according to sex, it was observed that boys showed a higher prevalence of overweight in almost half of the countries and a higher prevalence of obesity in almost all countries. These results are consistent with previous studies that pointed out a high prevalence of abdominal obesity among boys [55]. Differences of prevalence of overweight and obesity between genders have been related to geopolitical and cultural conditions [55].Eight articles compared data between 1980s and/or 1990s with 2000s [16, 19, 20, 22, 28, 32, 37, 50] and pointed out an increased prevalence of overweight and obesity in both sexes over this period. However, among Australian adolescents [38] the overweight and obesity prevalence increased significantly among boys but not among girls over the period 1997–2004. In the Australian National Children’s Nutrition and Physical Activity Survey 2007 (NCNPAS07) [14], 25% of boys and 30% of girls aged 9- to 13-year-olds and 25% of boys and 23% of girls aged 14- to 16-year-olds were overweight or obese using the IOTF criteria. A comparison of the 1985, 1995, and 2007 Australian national surveys of 7- to 15-year-olds indicated that Australian children are changing body shape to a more central fat distribution [14]. In USA, overweight and obesity prevalence among adolescents increased 4% in 2003 and 10% in 2007. Overweight and obesity prevalence increased by 3% and 18% among USA girls over this period. However, a cross-sectional analyses of a representative sample (n=4111) of the USA child and adolescent population (birth through 19 years of age) with data from the National Health and Nutrition Examination Survey 2009-10 (NHANES) indicated a prevalence of overweight and obesity among adolescents aged 12 through 19 years of 15.2% and 18.4%, respectively. Analyses of trends in obesity prevalence for the last two NHANES surveys (2007-08 and 2009-10) indicated that the prevalence of obesity in children and adolescents has not changed in 2009-10 compared with 2007-08 [13]. On the other hand, since 2004 the overweight and obesity trends were stabilized or decreased among German adolescents [32].In USA, substantial geographic disparities in adolescent overweight and obesity were found, with an apparent shift toward higher prevalence in 2007 for several states [20]. Generally, overweight and obesity prevalence was also higher in southern USA in 2007. Lobstein et al. [56] reported that children in Northern Europe countries generally tended to have lower overweight and obesity prevalence (10–20%) than in Southern Europe (20–35%). Also within the same country, the prevalence and trends of overweight and obesity may not be homogeneous according to different geographic regions [57]. In Italy, a north-south gradient in overweight and obesity prevalence among boys but also in overweight prevalence among girls was also reported [34]. A higher prevalence of overweight and obesity has been reported in Southern Spain in both children [58] and adults [59].It is important to note that the choice of a reference and a cut-off point will determine the absolute prevalence of overweight and obesity and its trends, and hence different information will be obtained from the papers [60]. The IOTF classification for adolescent overweight and obesity [6] is the most frequently used. Cole et al. [6] argued that the reference they published, supported by the IOTF, is less arbitrary and more international than others and recommended its use in international comparisons. Lately, Monasta et al. [61] suggested that the IOTF reference and cut-offs could be preferable to identify overweight and obesity both at individual and population levels because they are at least based on a crude association with ill and health later in life, namely, the definition of overweight and obesity at age 18 years. However, the IOTF cut-offs have been not recommended for clinical use when assessing an individual child’s growth [9, 62–64]. Furthermore, recent findings suggested that a universal BMI classification system for childhood and adolescent overweight and obesity may not correspond to a comparable level of body fatness in all populations [9]. The prevalence estimates may not accurately characterize the population groups most at risk of health disadvantages because the correlation of BMI with adiposity is highly variable and dependent on ethnic group [9, 60, 65, 66].


## 5. Limitations of the Study

The comparisons of overweight and obesity prevalence need interpretation with caution due to the difference in survey sampling methods, sample sizes, age range of subjects, quality of data in terms of height and weight measurement, and whether national programmes or strategies to tackle overweight and obesity are in place [57]. Even within the same country, the prevalence and trends of overweight and obesity may not be homogenous in view of different ethnicities, geographic regions, and socioeconomic status [57]. Only articles in English, Spanish, Italian, and Portuguese were included in this review.


## 6. Conclusions

The results of this review allow the following conclusions: (1) overweight and obesity prevalence is high; (2) obesity is higher among boys, although it is not clear which sex has a higher proportion of adolescents with overweight; (3) despite that there is no consensus about criteria to be used to classify adolescents as overweighed or obese, the most frequently used was the IOTF reference [6]. However, the international reference charts for monitoring the secular trends in childhood obesity need to be continually refined and evaluated [56]. The results of this study would contribute to guiding health planners and administrators to develop proper tools for adolescent obesity management.



---

*Source: 392747-2013-06-27.xml*