289

Asia Pac J Clin Nutr 2010;19 (2):289-293

Short Communication

Obesity screening for young Japanese males and females
using skin fold measurements: the classification revisited
Masaharu Kagawa PhD1,2,3, Kazuhiro Uenishi PhD4, Miki Mori BSc4, Hayato Uchida522
1
PhD , Deborah A Kerr PhD , Colin W Binns PhD , Andrew P Hills PhD
1Institute of Health and Biomedical Innovation, School of Human Movement Studies, Queensland Universityof Technology, Brisbane, Australia
2
Curtin Health Innovation Research Institute, School of Public Health, Curtin University of Technology,
Perth, Australia
3
Department of Health Promotion, National Institute of Public Health, Saitama, Japan
4
Kagawa Nutrition University, Saitama, Japan
5
School of Human Science and Environment, University of Hyogo, Japan
Anthropometric assessment is a simple, safe, and cost-efficient method to examine the health status of individuals. The Japanese obesity classification based on the sum of two skin folds (Σ2SF) was proposed nearly 40 years
ago therefore its applicability to Japanese living today is unknown. The current study aimed to determine Σ2SF
cut-off values that correspond to percent body fat (%BF) and BMI values using two datasets from young Japanese adults (233 males and 139 females). Using regression analysis, Σ2SF and height-corrected Σ2SF (HtΣ2SF)
values that correspond to %BF of 20, 25, and 30% for males and 30, 35, and 40% for females were determined.
In addition, cut-off values of both Σ2SF and HtΣ2SF that correspond to BMI values of 23 kg/m2, 25 kg/m2 and
30 kg/m2 were determined. In comparison with the original Σ2SF values, the proposed values are smaller by
about 10 mm at maximum. The proposed values show an improvement in sensitivity from about 25% to above
90% to identify individuals with ≥20% body fat in males and ≥30% body fat in females with high specificity of
about 95% in both genders. The results indicate that the original Σ2SF cut-off values to screen obese individuals
cannot be applied to young Japanese adults living today and modification is required. Application of the proposed values may assist screening in the clinical setting.

Key Words: anthropometry, Japanese, sum of skin folds, obesity, classification

INTRODUCTION
Anthropometry is a non-invasive, cost-efficient approachfor health assessment. Percentage body fat (%BF) andskin fold values are highly correlated with criterion bodycomposition assessment methods such as underwater
weighing (UWW) and dual energy x-ray absorptiometry(DXA).1-3 A major advantage of anthropometry is that
individuals, including the overweight and obese, can bescreened by clinicians in the field where resources may belimited.
In Japan, body composition estimation equations using
anthropometry were first proposed by Nagamine and Suzuki.4 Later, Nagamine proposed the classification of
overweight and obesity using the sum of two skin foldthicknesses (Σ2SF: triceps and subscapular) in different
age groups including adults (Table 1).5 The classification
is based on Nagamine and Suzuki’s equations and also
the assumption that the %BF values of 20 and 30% areappropriate cut-off points in the adult population.6
Recent screening protocols for obesity or the metabolic syndrome use the body mass index (BMI) or waist
circumference (WC) however Σ2SF is still widely used
for health assessment in Japan and included in the reference data for clinical use.7 In part, this may be due to thefact that neither BMI nor WC is a measure of body com-position per se and inconsistencies in classification andmeasurement protocols used in Japan8,9 compared with
the international consensus exist.10,11 There is ongoingdebate regarding the appropriateness of these measures.12
However, the Σ2SF classification was proposed somedecades ago and it is essential to confirm its usefulness toJapanese living today.
The aim of the current study was to examine the abilityof Nagamine’s Σ2SF classification to screen young Japanese adults today. By revising the classification, the study
enables us to observe any changes in subcutaneous fat
distribution pattern as well as relationships with %BF or
BMI among Japanese adults in the last 40 years.
MATERIALS AND METHODS
Two datasets consisting of 233 Japanese males and 139
Corresponding Author: Dr Masaharu Kagawa, Postdoctoral
Research Fellow, Institute of Health and Biomedical Innovation,
Queensland University of Technology, 60 Musk Avenue,
Kelvin Grove QLD 4059 Australia.
Tel: +61-7-3138-6091; Fax: +61-7-3138-6030
Email: m.kagawa@qut.edu.au; masaharuk@hotmail.com
Manuscript received 15 June 2009. Initial review completed 14
November 2009. Revision accepted 25 December 2009.

290

Obesity screening for Japanese using skin folds

Table 1. Classification of obesity for Japanese adults using the sum of two skin folds (triceps and subscapular)%BF (%)
Σ2SF (mm)Light obese
Males
Females
20
30
35
45

Obese
Males
25
45

Females
35
55

Severe obese
Males
Females
30
40
55
60

(modified from Nagamine5)

Japanese females respectively, aged between 18-40 years
were used in this study. Among the 233 Japanese males,
145 were recruited and measured in Perth, Western Australia and 88 were from Himeji, Hyogo prefecture, Japan.
All females were recruited and measured at Saitama prefecture, Japan. Data collection for the original studies wasapproved by the Human Research Ethics Committee ofappropriate institutions and each participant provided theirwritten informed consent prior to measurement sessions.
Anthropometric measurements such as stature, bodymass and skin folds at triceps, subscapular, iliac crest,
supraspinale and abdominal sites were conducted using
the international standard proposed by the International
Society for the Advancement of Kinanthropometry (ISAK).13
Male data was collected by a level three (instructor) andthree level one anthropometrists accredited by ISAK.
Female data was collected by the level three and a level
one anthropometrist. Technical error of measurements(TEM) were within the acceptable limits as recommended
in the literature.14 All landmarks were located by the level
three anthropometrist. From the anthropometric measurements, the BMI (kg/m2), Σ2SF, and height-corrected
sum of two skin folds (HtΣ2SF: Σ2SF x [170.18/stature incm]) were calculated using the “phantom” stature of
170.18 cm proposed elsewhere.15
Percentage body fat was calculated by first predicting
body density (BD) using the gender-specific body density
prediction equations proposed by Durnin and Womersley
and then using Siri’s equation.16,17 The Durnin andWomersley prediction equation was selected based on
previous studies that showed no significant differences in
predicted %BF values with results obtained from
DXA.18,19
All statistical analyses were completed using the SPSS
statistical package for Windows (version 14.0, SPSS Inc.,
Chicago, IL, 2005). Stepwise multiple regression analysis
was conducted using %BF as a dependent variable andΣ2SF, HtΣ2SF and age as independent variables. Similarly, relationships between BMI and Σ2SF as well as
HtΣ2SF were examined using BMI as an independent
variable. In order to normalize the results, Σ2SF, HtΣ2SF
and BMI were all transformed using natural logarithm.

Once cut-off values for Σ2SF equivalent to the Nagamine’s classification were identified, differences insensitivity (true positive/[true positive + false negative])and specificity (true negative/[true negative + false positive]) were compared between the proposed and Nagamine’s cut-off values. In all analyses, a significancelevel of 0.05 was applied.
RESULTS
The mean age, stature and body mass were 22.2 ± 3.6
years, 172.1 ± 5.3 cm, and 64.2 ± 8.8 kg for males, and20.4 ± 1.3 years, 158.8 ± 5.0 cm, and 52.5 ± 6.1 kg forfemales. Average BMI and %BF were within the “normal” range in both males (BMI: 21.7 ± 2.7 kg/m2; %BF:
16.5 ± 5.0%) and females (BMI: 20.8 ± 2.2 kg/m2; %BF:
27.8 ± 4.6%).
Based on equations derived from multiple linear regression analysis (data not shown), Σ2SF and HtΣ2SF
cut-off points at the %BF cut-off values adopted in the
Nagamine classification as well as BMI values of 23
kg/m2, 25 kg/m2 and 30 kg/m2 were calculated for eachgender (Table 2). Based on the relationship with the %BF
cut-off points used in the original classification, Σ2SF
values of 25 and 35 mm were found to be appropriate as
cut-off points to classify males and females as “lightobese”. Similarly, the BMI value of 23 kg/m2 had comparable Σ2SF and HtΣ2SF values at %BF values for “lightobese” and therefore may also be useful as a cut-off point.
As shown in Table 3, the proposed cut-off values provide
much higher sensitivity (90.2% for males and 90.7% forfemales) compared to the original cut-off values (27.5%
for males and 23.3% for females) and maintained comparable levels of specificity (97.7% for males and 94.8% forfemales) to the original cut-off values (100% in both genders). The results indicate that the use of the original cutoff values in the current young Japanese population may
misclassify those who may be at risk of obesity.
DISCUSSION
The current study examined the usefulness of the classification of obesity using the Σ2SF cut-off values proposed
by Nagamine in the early 1970s.5 The results indicate that

Table 2. Calculated skin fold cut-off values based on %BF and BMIClassification%BF (%)
Σ2SF (mm)HtΣ2SF (mm)BMI (kg/m2)
Σ2SF (mm)HtΣ2SF (mm)Light obese
Males
Females
20
30
24.8
34.6
25.1
32.2
23
23
22.6
37.6
22.8
34.9

Obese
Males
25
34.5
35.0
25
27.0
27.2

Females
35
48.5
45.3
25
45.2
41.8

Severe obese
Males
Females
30
40
48.1
68.1
48.9
63.7
30
30
39.6
67.8
39.8
62.2

M Kagawa, K Uenishi, M Mori, H Uchida, D Kerr, CW Binns and AP Hills
Table 3. Differences in sensitivity and specificity between the proposed Σ2SF cut-off values and the original
cut-off values for “Light obese” classification by Nagamine (1972) in a) males, and b) females.
a) MalesClassification
Proposed values
Σ2SF< 25 mm≥ 25 mm
Nagamine’s values
Σ2SF< 35 mm≥ 35 mmb) Females
Classification
Proposed values
Σ2SF< 35 mm≥ 35 mm
Nagamine’s values
Σ2SF< 45 mm≥ 45 mm

Specificity/Sensitivity tests*
%BF
< 20%
≥ 20%
177 (97.3)
55
46 (90.2)
%BF
< 20%
≥ 20%
182 (100.0)370
14 (27.5)
Specificity/Sensitivity tests*
%BF
< 30%
≥ 30%
91 (94.8)
45
39 (90.7)
%BF
< 30%
≥ 30%
96 (100.0)33
0
10 (23.3)* Sensitivity and specificity are stated as % within the brackets.

the Σ2SF values proposed nearly 40 years ago do not provide precise screening outcomes for young Japanese
adults today. The average stature and body mass of theparticipants were comparable to those reported in theJapanese Anthropometric Reference Data (JARD) collected in 2001.7 Also, considering the comparable resultswith the national nutrition survey results (e.g. 2004 data
for females),20 it can be stated that the database is representative of the general population for this specific age
group.
With consideration of the results of the height-adjusted
relative term (HtΣ2SF), the Σ2SF cut-off values of 25, 35
and 50 mm for males and 35, 45 and 65 mm for females
may be appropriate to screen obesity risk. Compared to
Nagamine’s classification, this is a reduction of about 10
mm for the “light obese” and “obese” cut-off values inboth genders and about a 5 mm reduction in males and a
5 mm increase in females for the “severe obese” cut-off
values. Assessment of sensitivity and specificity using the
proposed “light obese” cut-off values found that while the
Nagamine cut-off points can identify only about 1/4 of all
individuals with high %BF, the proposed cut-off values
can identify more than 90% of those who may requireclinical intervention. The decrease in the Σ2SF cut-off
values in young Japanese may be due to different measurement protocols, including the use of different skin foldcalipers. However, the difference may also be attributed
to a change in fat distribution pattern and its relationshipwith total adiposity. While the %BF of the current datasets were greater than the samples reported in Nagamineand Suzuki study,4 quartile values of both triceps andsubscapular skin folds were comparable in both genders(data not shown). This may indicate that young Japanese
adults are now likely to have a smaller upper body subcutaneous fat accumulation relative to their total adiposity.
In addition, quartile values for abdominal skin fold were291

greater in males but smaller in females compared with theresults reported by Nagamine and Suzuki (data notshown).4 While the study cannot identify the causes, theresults may suggest a possible change in subcutaneous fat
distribution pattern over 45 years in both genders.
In addition to the cut-off points based on %BF, thecurrent study also used BMI to determine Σ2SF cut-off
values. Although the values were slightly different, thedatasets showed consistency in the Σ2SF cut-off values
estimated based on a BMI value of 23 kg/m2 and %BF of
20% in males and 30% in females. In addition, the proposed Σ2SF value for males at the BMI value of 23 kg/m2
was comparable to the results of another study (males: 25mm; females: 40 mm) using a larger sample size.21 The
proposed value for females was about 5 mm lower thanthe previous study, which may be attributed to a smaller
sample size (139 vs 549) as well as narrower age range offemales in the current study.
Results from the current study suggest that Σ2SF cutoff values used to screen for obesity in young Japanese
adults may need to be modified by about 10 mm. While
the validity of the revised Σ2SF cut-off values needs to be
examined further, the current study indicated that the revised values will be useful in the clinical setting. However the reliability and accuracy of anthropometry largely
depends on the skill of the technician and the consistentuse of the chosen protocol. Therefore, it is fundamental
that measurers and clinicians are well-trained and maintain adequate measurement skills to minimize measurement errors. Skin folds taken by trained measurers canprovide reliable fat distribution patterns and level of adiposity. These findings may not be affected by calculation
errors from prediction equations and hydration status ofparticipants which influence BIA results. In addition,
while the revised values are specific to young Japanese
adults, the same approach may be useful to assess thehealth status of populations in other countries where resources are limited.
It is important to acknowledge the limitations of thepresent study. Percentage body fat was estimated fromgender-specific body density prediction equations by
Durnin and Womersley.16 Although the equations hadhigh correlations and small inter-method variability compared with the results obtained from DXA,18,19 the application of prediction equations using anthropometric variables may involve bias in the estimation of %BF. In order
to confirm the applicability of the proposed Σ2SF cut-off
values, it is recommended that further studies be conducted to measure the body composition of participants
using DXA or total body water assessed using the deuterium dilution technique. Further, it is also recommended
that future studies include a larger sample size across awider age range.
AUTHOR DISCLOSURES
There were no conflict of interest among the authors and nofinancial grant or other funding was obtained for the study.

REFERENCES
1. Pritchard JE, Nowson CA, Strauss BJ, Carlson JS, Kaymakci B, Wark JD. Evaluation of dual energy X-ray absorp-

292

Obesity screening for Japanese using skin folds

tiometry as a method of measurement of body fat. Eur J Clin
Nutr. 1993;47:216-28.
2. Fogelholm M, Lichtenbelt WVM. Comparison of bodycomposition methods: A literature analysis. Eur J Clin Nutr.
1997;51:495-503.
3. Wagner DR, Heyward VH. Techniques of body compositionassessment: A review of laboratory and field methods. Res
Q Exerc Sport. 1999;70:135-49.
4. Nagamine S, Suzuki S. Anthropometry and body composition of Japanese among men and women. Hum Biol.
1964;36:8-15.
5. Nagamine S. Hikashibou kara no himan no hantei Nihon
Ishikai Zasshi. 1972;68:919-24. (in Japanese)
6. Huenemann RL, Hampton MC, Shapiro LR, Behnke AR.
Adolescent food practices associated with obesity. Fed Proc.
1966;25:4-10.
7. JARD. Japanese anthropometric reference data. Eiyou Hyouka to Chiryou. 2002;19:8-81. (in Japanese)
8. The Examination Committee of Criteria for 'Obesity Disease' in Japan. New criteria for 'obesity disease' in Japan.
Circ J. 2002;66:987-92.
9. Kanazawa M, Yoshiike N, Osaka T, Numba Y, Zimmet P,
Inoue S. Criteria and classification of obesity in Japan andAsia-Oceania. Asia Pacific J Clin Nutr. 2002;11:S732-S7.
10. WHO expert consultation. Appropriate body-mass index for
Asian populations and its implications for policy and intervention strategies. Lancet. 2004;363:157-63.
11. International Diabetes Federation. The IDF consensus
worldwide definition of the metabolic syndrome. 2008/3/18[cited 2009/5/30]; Available from: http://www.idf.org/webdata/docs/IDF_Meta_def_final.pdf
12. Ito H, Nakasuga K, Ohshima A, Maruyama T, Kaji Y,
Harada M et al. Detection of cardiovascular risk factors byindices of obesity obtained from anthropometry and dualenergy X-ray absorptiometry in Japanese individuals. Int J
Obes. 2003;27:232-7.

13. ISAK. International standards for anthropometric assessment. Canberra: ISAK 2001.
14. Gore C, Norton K, Olds T, Whittingham N, Birchall K,
Clough M et al. Accreditation in anthropometry: an Australian model. In: Norton K, Olds T, eds. Anthropometrica.
Sydney: University of New South Wales Press. 1996. pp.
395-411.
15. Ross WD, Marfell-Jones MJ. Kinanthropometry. In: MacDougall JD, Werger HA, Green HJ, eds. Physiological testing of the high-performance athlete. 2 ed. Champaign: Human Kinetics Books. 1991. pp. 223-68.
16. Durnin JVGA, Womersley J. Body fat assessed from total
body density and its estimation from skinfold thickness:measurements on 481 men and women aged from 16 to 72
years. Br J Nutr. 1974;32:77-97.
17. Siri WE. Body volume measurement by gas dilution. In:
Brozek J, Henschel A, eds. Techniques for measuring bodycomposition. Washington, DC: National Academy of Sciences. 1961. pp. 108-17.
18. Kagawa M, Kerr D, Binns C. Ethnic differences in the BMI%BF relationships between young Japanese and AustralianCaucasian males living in Australia using dual-energy x-ray
absorptiometry. Asia Pac J Public Health. 2003;15:S27-S32.
19. Kagawa M, Kuroiwa C, Uenishi K, Mori M, Ishida H, Binns
C. Estimation of body fat in Japanese females using anthropometry, multi-frequency bioelectrical impedance analysis(MFBIA), and dual energy x-ray absorptiometry (DXA). J
Sci Med Sport. 2005;8:53. (Abstract)
20. Ministry of Health Labour and Welfare. Tha National Nutrition Survey in Japan, 2004. Tokyo; 2006. (in Japanese)
21. Kagawa M, Tahara Y, Byrne NM, Moji K, Tsunawake N,
Hills AP. Are Japanese obesity criteria useful for screening
at risk Japanese? Consideration from anthropometric indices-percentage body fat relationships. Asia Pac J Public
Health. 2008;20:102-10.

M Kagawa, K Uenishi, M Mori, H Uchida, D Kerr, CW Binns and AP Hills

293

Short Communication

Obesity screening for young Japanese males and females
using skin fold measurements: the classification revisited
Masaharu Kagawa PhD1,2,3, Kazuhiro Uenishi PhD4, Miki Mori BSc4, Hayato Uchida522
1
PhD , Deborah A Kerr PhD , Colin W Binns PhD , Andrew P Hills PhD
1Institute of Health and Biomedical Innovation, School of Human Movement Studies, Queensland University ofTechnology, Brisbane, Australia
2
Curtin Health Innovation Research Institute, School of Public Health, Curtin University of Technology, Perth,
Australia
3
Department of Health Promotion, National Institute of Public Health, Saitama, Japan
4
Kagawa Nutrition University, Saitama, Japan
5
School of Human Science and Environment, University of Hyogo, Japan

皮脂厚度測量用於日本年輕成人之肥胖篩檢：分級的重新檢視體位測量是一個簡單、安全與經濟的檢測個人健康狀況的方法。日本以兩項皮脂
厚度總和來做肥胖分級的方法，是在約 40 年前所提出，因此是否適用於現今的
日本人是未知的。本篇研究的目的是使用兩個日本年輕成人資料庫(233 位男性及139 位女性)，根據其體脂肪百分比及身體質量指數來檢視兩項皮脂厚度總和的肥胖切點。使用回歸分析，計算出了符合體脂肪百分比切點 (男性 20%、25%、30%；女性 30%、35%、40%)的兩項皮脂厚度總和及經身高校正的兩項皮脂厚度
總和的切點值；此外，也計算出了符合身體質量指數切點 (23、25、30 kg/m2)的
皮脂厚度總和及經身高校正的皮脂厚度總和的切點值。與原始的兩項皮脂厚度總
和切點值比較，本文建議值都較小，差距最多達 10 mm。建議值對於分辨男性≧20%體脂肪及女性≧30%體脂肪有較好的靈敏度(從 25%提昇至 90%)，在兩個
性別都有較高的特異度(95%)。結果指出，以原始的兩項皮脂厚度總和切點來評估肥胖，並不適用於現今的日本年輕成人，修正是必要的。應用本文建議值可以幫助臨床上的評估。
關鍵字：體位測量、日本、皮脂厚度總和、肥胖、分級