第15回 Auxology分科会研究会 　2000年11月25日 　大妻女子大学

　

Maya in Disneyland: Growth and Health

　

　

B. BOGIN (1), P.K. SMITH (2), J. LOUCKY (3), A.B. ORDEN (4), Ma. I. VARELA SILVA (5), M. KAPELL (1), S .MACNEE (1).

(1) Behavioral Sciences and (2) Social Sciences, University of Michigan-Dearborn, Dearborn,
(3) Anthropology, Western Washington University, Bellingham, WA (4) Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata. Argentina.
(5) Sports Sciences and Physical Education, University of Coimbra. Portugal.

　

Introduction
　　It is known from studies in Japan, China, Argentina, Poland and Mexico, that environmental factors are powerful determinants of body proportion. Both secular change in amount and rate of growth and existing difference in SES between groups are associated with changes in the ratio of trunk length to leg length (Bogin, 1999). Our previous research shows that Maya refugee children living in the United States are significantly taller than Maya children living in Guatemala (Bogin & Loucky, 1997). We did not measure body proportions in that study, but we hypothesized that an increase in relative leg length accompanies the increase in stature.

Samples
　　A new study of the growth of Maya refugee children began in 1999. We measured the height, weight, and sitting height of 360 Maya children ages 6 to 12 years old, living in south central Los Angeles in February 1999, and Indiantown, Florida, in March 2000. With these data we computed the sitting height ratio [(sitting height/height) * 100] and body mass index (body weight/height2). We compared these newer data with our Maya sample from 1992 of Maya living in USA (n=174) and a sample of Maya schoolchildren living in rural Guatemala measured in 1998-99 (n=1297). The Guatemalan data were kindly supplied by L. Rios of the Universidad Autonoma de Madrid.

Analysis
　　Anthropometric reference data from the NHANES I & II surveys of the United States (Frisancho, 1993) are used as a baseline for comparison in each variable.
　　Analysis of variance (ANOVA) was used to evaluate differences between samples. After adjusting for the effect of age and sex, our results show that the Maya children of both the 1992 (Maya-USA1992) and the 1999 and 2000 (Maya-USA2000) samples are significantly taller and heavier than Maya children living in Guatemala (Maya-Guat). The Maya living in the USA also have greater BMI values and smaller sitting height ratios (Fig. 4). All differences are significant at p<.01. A smaller sitting height ratio generally indicates a child with relatively longer legs. Similarly, the Maya-USA 2000 sample are significantly taller, heavier, and have higher BMI than the Maya-USA 1992 sample. Sitting height was not measured in 1992. Compared with the NHANES references, all of Maya are shorter and have higher sitting height ratios, i.e, relatively shorter legs. The Maya-USA 1992 is equal in body weight to the reference, but the Maya-USA 2000 is above the reference. Both samples are above the reference for body mass index.

Conclusion
　　Our findings add further support to the literature of developmental plasticity in body proportions. The results indicate that between 1992 and the present, there is a clear, and positive, trend in growth of Maya children living in United States. The reasons for this trend are likely due to improvements in the environment for growth. All Maya in the USA have access to clean drinking water, health services, and education that may not exist in Guatemala. The Florida Maya children participate in school breakfast and lunch programs. These health and nutritional changes are known to result in greater stature. Our findings support the hypothesis that the increase in stature is due mostly to relatively longer legs. Body weight and body mass index of Maya children in USA have increased at a faster pace than their height. The Maya 1992 and 2000 samples are well above the reference data. This indicates a trend to childhood obesity. Similar risk for obesity has been observed in other samples of migrants to the USA from Latin America. Martorell et al (1987) call this the short and plump syndrome. The disharmony between weight and height may predispose these children to greater risks for obesity related disease. We predict that the positive trend in height seen between 1992 and 2000 will continue. Eventually heights and weights should achieve a more harmonious relationship, reducing risks for disease.

Literature cited
Bogin, B (1999) Patterns of Human Growth, 2nd ed. Cambridge: Cambridge University Press.

Bogin, B & Loucky, J (1997) Plasticity, political economy, and physical growth status of Guatemala Maya children living in the United States. American Journal of Physical Anthropology, 102, 17-32.

Frisancho, AR (1993) Anthropometric Standards for the Assessment of Growth and Nutritional Status. Ann Arbor: University of Michigan Press.

Martorell, R, Mendoza, SF, Castillo, RO, Pawson, LG, & Budge, CC (1987). Short and plump physique of Mexican-American children. American Journal of Physical Anthropology, 73, 475-487.