Book contents
- Frontmatter
- Contents
- List of contributors
- Preface
- Acknowledgments
- List of abbreviations
- 1 Fetal nutrition
- 2 Determinants of intrauterine growth
- 3 Aspects of fetoplacental nutrition in intrauterine growth restriction and macrosomia
- 4 Postnatal growth in preterm infants
- 5 Thermal regulation and effects on nutrient substrate metabolism
- 6 Development and physiology of the gastrointestinal tract
- 7 Metabolic programming as a consequence of the nutritional environment during fetal and the immediate postnatal periods
- 8 Nutrient regulation in brain development: glucose and alternate fuels
- 9 Water and electrolyte balance in newborn infants
- 10 Amino acid metabolism and protein accretion
- 11 Carbohydrate metabolism and glycogen accretion
- 12 Energy requirements and protein-energy metabolism and balance in preterm and term infants
- 13 The role of essential fatty acids in development
- 14 Vitamins
- 15 Normal bone and mineral physiology and metabolism
- 16 Disorders of mineral, vitamin D and bone homeostasis
- 17 Trace minerals
- 18 Iron
- 19 Conditionally essential nutrients: choline, inositol, taurine, arginine, glutamine and nucleotides
- 20 Intravenous feeding
- 21 Enteral amino acid and protein digestion, absorption, and metabolism
- 22 Enteral carbohydrate assimilation
- 23 Enteral lipid digestion and absorption
- 24 Minimal enteral nutrition
- 25 Milk secretion and composition
- 26 Rationale for breastfeeding
- 27 Fortified human milk for premature infants
- 28 Formulas for preterm and term infants
- 29 Differences between metabolism and feeding of preterm and term infants
- 30 Gastrointestinal reflux
- 31 Hypo- and hyperglycemia and other carbohydrate metabolism disorders
- 32 The infant of the diabetic mother
- 33 Neonatal necrotizing enterocolitis: clinical observations and pathophysiology
- 34 Neonatal short bowel syndrome
- 35 Acute respiratory failure
- 36 Nutrition for premature infants with bronchopulmonary dysplasia
- 37 Nutrition in infants with congenital heart disease
- 38 Nutrition therapies for inborn errors of metabolism
- 39 Nutrition in the neonatal surgical patient
- 40 Nutritional assessment of the neonate
- 41 Methods of measuring body composition
- 42 Methods of measuring energy balance: calorimetry and doubly labelled water
- 43 Methods of measuring nutrient substrate utilization using stable isotopes
- 44 Postnatal nutritional influences on subsequent health
- 45 Growth outcomes of preterm and very low birth weight infants
- 46 Post-hospital nutrition of the preterm infant
- Index
- References
21 - Enteral amino acid and protein digestion, absorption, and metabolism
Published online by Cambridge University Press: 10 December 2009
- Frontmatter
- Contents
- List of contributors
- Preface
- Acknowledgments
- List of abbreviations
- 1 Fetal nutrition
- 2 Determinants of intrauterine growth
- 3 Aspects of fetoplacental nutrition in intrauterine growth restriction and macrosomia
- 4 Postnatal growth in preterm infants
- 5 Thermal regulation and effects on nutrient substrate metabolism
- 6 Development and physiology of the gastrointestinal tract
- 7 Metabolic programming as a consequence of the nutritional environment during fetal and the immediate postnatal periods
- 8 Nutrient regulation in brain development: glucose and alternate fuels
- 9 Water and electrolyte balance in newborn infants
- 10 Amino acid metabolism and protein accretion
- 11 Carbohydrate metabolism and glycogen accretion
- 12 Energy requirements and protein-energy metabolism and balance in preterm and term infants
- 13 The role of essential fatty acids in development
- 14 Vitamins
- 15 Normal bone and mineral physiology and metabolism
- 16 Disorders of mineral, vitamin D and bone homeostasis
- 17 Trace minerals
- 18 Iron
- 19 Conditionally essential nutrients: choline, inositol, taurine, arginine, glutamine and nucleotides
- 20 Intravenous feeding
- 21 Enteral amino acid and protein digestion, absorption, and metabolism
- 22 Enteral carbohydrate assimilation
- 23 Enteral lipid digestion and absorption
- 24 Minimal enteral nutrition
- 25 Milk secretion and composition
- 26 Rationale for breastfeeding
- 27 Fortified human milk for premature infants
- 28 Formulas for preterm and term infants
- 29 Differences between metabolism and feeding of preterm and term infants
- 30 Gastrointestinal reflux
- 31 Hypo- and hyperglycemia and other carbohydrate metabolism disorders
- 32 The infant of the diabetic mother
- 33 Neonatal necrotizing enterocolitis: clinical observations and pathophysiology
- 34 Neonatal short bowel syndrome
- 35 Acute respiratory failure
- 36 Nutrition for premature infants with bronchopulmonary dysplasia
- 37 Nutrition in infants with congenital heart disease
- 38 Nutrition therapies for inborn errors of metabolism
- 39 Nutrition in the neonatal surgical patient
- 40 Nutritional assessment of the neonate
- 41 Methods of measuring body composition
- 42 Methods of measuring energy balance: calorimetry and doubly labelled water
- 43 Methods of measuring nutrient substrate utilization using stable isotopes
- 44 Postnatal nutritional influences on subsequent health
- 45 Growth outcomes of preterm and very low birth weight infants
- 46 Post-hospital nutrition of the preterm infant
- Index
- References
Summary
Introduction
The amino acid requirements of neonates continue to be an area of investigation despite numerous studies, due to the complexity of determining these requirements within the ever-changing biochemical environment of the developing infant. In the following discussion some of the issues related to digestibility and absorption, special aspects of development as they impact on requirements – including amino acid metabolism and infant responses to amino acid variations in the diet – will be addressed.
Protein is often assessed for its function in infant nutrition based on its role in supporting growth. However, protein is responsible for supplying some 20 individual amino acids with a variety of specific functions, as well as serving as precursors for a number of biologically active proteins (for example enzymes, cytokines, and immunoglobulins) that have more complex roles than to merely supply the amino acid building blocks for the body's proteins. The major conundrum in determining protein requirements for infants is that human milk proteins are fundamentally different than the proteins supplied in various substitution formulas. Human milk is perfectly satisfactory nutrition for the healthy term infant (and is also usually satisfactory for preterm infants when supplemented with additional nutrients to support the greater requirements of these infants). Thus, the determination of infant protein requirements is often an exercise in comparing human milk protein nutriture to various possible substitutes (adapted cow milk or soy proteins, usually).
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- Information
- Neonatal Nutrition and Metabolism , pp. 332 - 339Publisher: Cambridge University PressPrint publication year: 2006