NUTRITION PRINCIPLES OF INFANTS

NUTRITION PRINCIPLES OF INFANTS
Nutrient requirements
• Energy, measured as cal/kg/d
• Carbohydrates
• Water
• Minerals and trace elements
• Protein
• Vitamins
• Fat

Energy needs
• The exact energy needs of a given neonate depend upon several factors, including postnatal age, weight, gest age, route of energy intake, growth rate, activity, and thermal environment.

• Infants who are ill or experiencing stressful situations (sepsis, surgery, BPD) have higher energy requirements.

• Infants receiving parenteral nutrition need less energy for adequate growth. Since they do not need to absorb the provided nutrients, they have no fecal losses. As a result, 70-90 cal/kg/d with 2.4-2.8 g/kg/d of protein may be adequate for growth.

• Protein is not an ideal source of energy; rather, it is provided as a building block for new tissue. If adequate nonprotein calories are provided, the nitrogen balance in the infant is positive, and the protein provided is used to build new tissue. Therefore, even if energy intake from protein is included in calculations of total energy intake, not all the protein-derived calories are available for energy expenditure.

• The ideal energy ratio is to provide 65% of the energy as carbohydrates and 35% as lipids. Providing more than 165-180 cal/kg/d is of no benefit.

• As an example, the total energy needs of a growing enterally fed premature infant without any acute illness are listed as follows:
o Resting expenditure: 50 cal/kg/d
o Minimal activity: 4-5 cal/kg/d
o Occasional cold stress: 10 cal/kg/d
o Fecal loss (10-15% of intake): 15 cal/kg/d
o Growth (4.5 cal/g of growth): 45 cal/kg/d
o Total required to produce a 10 g/d weight gain: 125 cal/kg/d