|Effects of Improved Nutrition in Early Childhood : The institute of Nutrition of Central America and Panama (INCAP) Follow-up Study; Proceedings of an IDECG workshop, July 1990, Bellagio, Italy, Supplement of The Journal of Nutrition (International Dietary Energy Consultative Group - IDECG, 1994, 198 pages)|
|Nutritional supplementation during the preschool years and physical work capacity in adolescent and adult Guatemalans(¹,²)|
JERE D. HAAS.*³ ELKIN J. MARTINEZ. SCOTT MURDOCH,* ELIZABETH CONLISK,* JUAN A. RIVERA AND REYNALDO MARTORELL§
*Division of Nutritional Sciences, Cornell
University, Ithaca NY 14853-6301, Facultad de Medicina, Unioersidad de
Antioquia, Medellín, Colombia, Centro de Investigaciones en Salud
Pública, Instituto Nacional de Salud Pública, 62508 Cuernaaaca, Morelos, Mexico,
and §Department of International Health, The Rollins School of Public
Health of Emory University, Atlanta, GA 30322
¹ Presented in the symposium on Nutrition in Early Childhood and its Long-term Functional Significance, FASEB' April 6, 1992, Anaheim, CA. Published as a supplement to The Journal of Nutrition Guest editors for this supplement publication were Reynaldo Martorell, The Rollins School of Public Health of Emory University, Atlanta, GA and Nevin Scrimshaw, The United Nations University, Boston, MA.
²upported by NIH grant numbers ROI-HD22440 and T32 HD07331.
³ To whom correspondence should be addressed: Division of Nutritional Sciences, 211 Savage Hall, Cornell University, Ithaca, NY 14853-6301.
A follow-up study (1988-89) was carried out in 364 rural Guatemalans, 11-27 y of age, who earlier had participated in a nutritional supplementation experiment. Among its objectives was the assessment of the long-term effects of the nutrition intervention on physical work capacity. Subjects and their mothers from two villages had available a high-energy, high-protein supplement (Atole: 163 kcal/682 kJ and 6.4 g protein per serving or 180 mL), whereas in two other villages a low-energy, no-protein supplement (Fresco: 59 kcal/247 kJ per 180 mL) was provided. Consumption was ad libitum. Maximum oxygen consumption (VO2max) at follow-up was significantly greater in Atole compared with Fresco subjects of both sexes. In subjects 14-19 y, exposed to supplementation throughout gestation and the first 3 y of life, Atole males had a significantly higher VO2max (2.62 L/min) than Fresco males (2.24 L/min), the differences remaining significant even after controlling for body weight and fat-ter mass; also, there was a significant positive relationship between amount of supplement consumed and VO2max. The supplementation effect in females of similar age was not statistically significant.. It is concluded that early nutritional improvements can have long-lasting effects on physical performance. J. Nutr. 125: 1078S-1089S, 1995.
INDEXING KEY WORDS:
Most evaluations of nutritional interventions in children have focused on outcomes measured during or shortly after the intervention has occurred. Although at least one study has examined the relation ship of childhood nutritional status and physical performance during adolescence (Satyanarayana et al. 1979), no studies have reported on the long-term effects of early nutritional interventions on later performance. Achieved growth, as measured by body size and composition, is an indicator of general constitutional development of the individual. It reflects functional aspects of development and performance and thus is a good proxy for overall well being. One important measure of functional performance that has been shown to be related to current nutritional status, as well as to anthropometric indicators of past nutritional status, is physical work capacity (Spuur 1983).
There are very few studies of work capacity in undernourished children. The single prospective study reported in the literature found no relationship between height at 5 y and submaximal work capacity adjusted for body weight at adolescence (Satyanara-yana et al. 1979). However, Spurr (1983) noted in these same data a strong negative relationship between height at age 5 and the percentage of maximal work capacity at which the submaximal work load was carried out. This means that the shortest adolescents would have the least endurance. The most extensive study of anthropometric characteristics and work capacity in undernourished children was conducted by Spurr and colleagues in Call, Colombia (1982a, 1982b, 1983, 1984). This cross-sectional study of 1013 boys (7-15 y) demonstrated a significantly lower maximal oxygen consumption (VO2max) in children with low weight-for-age and low weight-for-height than in anthropometrically normal children. These results, along with those from India (Satyanarayana et al. 1979), Brazil (Desai et al. 1984) and East Africa (Davies 1977), suggest that reduced body weight, probably reflecting less fat-free mass (FFM), accounts for the reduced work capacity seen in adolescents who were undernourished as young children. However, other evidence suggests that concurrent physical activity and anemia affect work capacity independently of variation in muscle mass in Tanzanian youths and young adults (Davies 1974).
None of the studies has examined the possibility that the same factors that cause poor growth also affect maturation during adolescence (Frisancho et al. 1970); thus, the relationship between body size and work capacity during adolescence may be due to retarded maturation because the latter affects work capacity independently (Bouchard et al. 1976, Kemper and Verschuur 1987). No studies have been made of the interrelationships among maturation, body weight, body composition and work capacity in adolescents undernourished as young children. It is not clear how much of the reduced adolescent body weight and its components of fat and lean tissue are a function of growth retardation in height that occurred in early childhood and how much is a reflection of current nutritional problems.
Although the evidence from previous research of the effects of past nutritional status on growth, maturity and physical performance during adolescence have been suggestive of a long-term impact of early nutrition on later development, these studies have been retrospective or used indirect methods to ascribe causality to nutritional effects. In this paper we test the hypothesis that improved nutrition during early life results in improved physical work capacity during adolescence and early adulthood.