Author
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Heird, William |
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Submitted to: Nestle Nutrition Workshop
Publication Type: Book / Chapter Publication Acceptance Date: 8/5/1999 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Low birth weight (LBW) infants who receive no nitrogen intake during early life experience nitrogen losses of up to 180 mg/kg/d, or a daily loss of 1.0% of body protein stores. Amino acid intake of about 1.0g/kg/d appears to reverse the negative nitrogen balance and a higher intake results in positive balance. This appears to be mediated by an increase in endogenous protein synthesis with minimal effects on endogenous protein breakdown. Achievement of a positive balance of 160 mg/kg/d should result in lean body mass deposition of about 5g/kg/d (1g/kg/d of protein plus accompanying intracellular fluid). A higher amino acid intake results in greater rates of lean body mass deposition and, perhaps, earlier resumption of normal growth. The functional consequences of inadequate early nutrition are not clear. Since growth and development of the central nervous system is particularly rapid during the third trimester, the impact of inadequate nutrition during this period is likely to be particularly detrimental. Indeed, studies show that LBW infants fed a preterm formula (higher protein intake) between birthweight's being regained and discharge have higher neurodevelopmental indices at both 18 mos and 7-8 years of age than infants fed formula with a lower content of protein (and other nutrients). LBW infants usually experience some catch-up growth. The nutrient requirements for which, are a function of the amount of catch-up needed and the duration over which it is achieved, e.g., the requirements to produce catch-up of 500g over 50 days are those necessary to support weight gain of an additional 10 g/d but the requirements to achieve this within 25 days are greater and those for achieving it within 100 days are less. |
