Applied nutritional investigationHarmonization of anthropometric measurements for a multicenter nutrition survey in Spanish adolescents☆
Introduction
Because of its importance to health, body composition is commonly investigated in epidemiologic, clinical, and population studies. Reliable methods for measurement of body fat and fat distribution therefore are important. During the past decade, investigators have emphasized the accuracy of newer techniques, such as dual-energy x-ray absorptiometry, magnetic resonance imaging, and computed tomography, for measuring body composition; nevertheless, anthropometry is the most widely used method, and it recently has been used to estimate fat distribution.1, 2 The distinct advantages of anthropometry are that it is portable, non-invasive, inexpensive, and useful in field studies, and there is a substantial literature available on the subject.3
Although the need for accurate anthropometric measurement has been repeatedly stressed, reports on growth and physical measurements in human populations rarely include estimates of measurement error. Reliability is the degree to which within-subject variability is due to factors other than measurement error variance or physiologic variation. The lower the variability between repeated measurements of the same subject by one (intraobserver differences) or two or more (interobserver differences) observers, the greater is the precision. The most commonly used measures of precision are the technical error of measurement (TEM) and the coefficient of reliability (R). The use of two error estimates, TEM and R, can provide most of the information needed to determine whether a series of anthropometric measurements can be considered accurate.4 As with any quantitative biological measure, in anthropometric assessment it is important to minimize error. Poor precision in measurement of an anthropometric variable will lead to underestimation of correlations with other variables.5 The main sources of error of imprecision are random imperfections in the measuring instruments or in the measuring and recording techniques.
Adolescence is a decisive period during human life because of multiple physiologic and psychological changes that take place. We developed a research project to evaluate the nutrition status of Spanish adolescents from five cities, Granada, Madrid, Murcia, Santander, and Zaragoza, which is called the Alimentación y Valoración del Estado Nutricional en Adolescentes (AVENA Study). Before carrying out the field work, we conducted a pilot study. For anthropometric assessment, in the pilot study we standardized the methods of measurement and obtained the intra- and interobserver errors of measurement. We describe the standardization process and the reliability of the anthropometric measurements carried out in the pilot study.
Section snippets
Population and design
In September 2000, we conducted a 2-d theoretical and practical workshop in Madrid with the five researchers who planned to perform the anthropometric measurements. All five anthropometrists had experience in the anthropometric assessment of nutrition status. The aim of the workshop was to standardize the methodology and use it as a reference, as determined by an experienced anthropometrist (L.A.M.).6, 7, 8 In October 2000, we conducted the pilot study in the five cities to assess the
Results
Table II shows the intraobserver TEM and %R for each anthropometric measurement in the five cities. For skinfold thickness, TEMs in general were smaller than 1 mm, except for the suprailiac skinfold in Madrid and the thigh skinfold in Madrid and Santander. For circumferences, TEMs were smaller than 1 cm, except for waist circumference in Murcia and hip circumference in Granada, Madrid, Murcia, and Santander. Reliability for skinfold thickness was greater than 95% for all cases, except for
Discussion
In choosing the instrument to assess nutrition status, researchers often elect to measure only height and weight. These measures are quick and simple and require only limited training. More comprehensive measurement sets that include skinfold thickness and circumference require more training and produce different degrees of error. Skinfold thickness is accepted as body fatness predictor for two reasons: approximately 40% to 60% of total body fat is in the subcutaneous region of the body, and
Acknowledgements
The authors thank all the adolescents who participated in this pilot study, especially those from the Colegio Escuelas Pías (Zaragoza, Spain) who participated in the intra- and interobserver assessments.
References (32)
- et al.
Body composition assessed on the basis of arm circumference and triceps skinfold thicknessa new index validated in children by magnetic resonance imaging
Am J Clin Nutr
(1997) - et al.
Compressibility of skinfolds and the measurement of subcutaneous fatness
Am J Clin Nutr
(1979) - et al.
Use of anthropometric measures to assess weight loss
Am J Clin Nutr
(1978) - et al.
Secular increases in body fat percentage in male children of Zaragoza, Spain, 1980–1995
Prev Med
(2001) - et al.
Prediction of intra-abdominal and subcutaneous abdominal adipose tissue in healthy pre-pubertal children
Int J Obes
(1998) - et al.
Indices of body fat distribution in Spanish children aged 4.0 to 14.9 years
J Pediatr Gastroenterol Nutr
(1997) - et al.
Anthropometry in body composition. An overview
Ann NY Acad Sci
(2000) - et al.
Intra- and inter-observer error in anthropometric measurement
- et al.
Interval estimates for correlation coefficients corrected for within-person variationimplications for study design and hypothesis testing
Am J Epidemiol
(1988) - et al.
Fat distribution in obese and non obese children and adolescents
J Pediatr Gastroenterol Nutr
(1998)
Trends in body mass index and overweight prevalence among children and adolescents in the region of Aragón (Spain) from 1985 to 1995
Int J Obes
Body mass index, triceps skinfold and waist circumference in screening for adiposity in male children and adolescents
Acta Paediatr
Anthropometric measurement error and the assessment of nutritional status
Br J Nutr
Standards for subcutaneous fat in British children. Percentiles for thickness of skinfolds over triceps and below scapula
BMJ
Anthropometry, physique, body composition and maturity
Anthropometric standards for the assessment of growth and nutritional status
Cited by (0)
- ☆
This study was supported by the Spanish Ministry of Health (FIS 00/0015).
- *
Coordinator: A. Marcos, Madrid. Principal Investigators: M. Bueno, Zaragoza; M. J. Castillo, Granada; M. García Fuentes, Santander; A. Marcos, Madrid; S. Zamora, Murcia. Collaborating Centers: Universidad de Granada (M. J. Castillo, M. D. Cano, Biochemistry; A. Gutierrez, J. L. Mesa, J. Ruiz, physical capacity; M. Delgado, P. Tercedor, physical activity); Instituto de Nutrición y Bromatología CSIC-UCM, Madrid (A. Marcos, M. Gonzalez-Gross, M. Joyanes, F. Sanchez-Muñiz, E. Nova, S. Medina, J. Weinberg, S. Gomez, A. Montero, B. de la Rosa, S. Sanmartin, J. Romeo, R. Alvarez, coordination, immunology; L. Barrios, statistical analysis; A. Leyva, psychological assessment); Departamento de Fisiología, Universidad de Murcia, Murcia (S. Zamora, M. Garaulet, F. Perez-Llamas, J. C. Baraza, J. F. Marin, F. Perez de Heredia, M. A. Fernandez, C. González, R. García, C. Torralba, E. Donat, E. Morales, M. D. García, J. A. Martínez, J. J. Hernandez, A. Asensio, F. J. Plaza, M. J. Lopez, diet analysis); Departamento de Pediatría, Universidad de Cantabria, Santander (M. García Fuentes, D. Gonzalez-Lamuño, P. de Rufino, R. Perez Prieto, M. D. Fernandez, T. Amigo, genetic study); Universidad de Zaragoza, Zaragoza (M. Bueno, L. S. Moreno, A. Sarría, J. Fleta, G. Rodríguez, C. M. Gil, M. I. Mesana, J. A. Casajús, anthropometric assessment).