What are high calorie formulas?

High Calorie Formulas

High calorie formulas are specialized nutritional products with increased caloric density (24-30+ kcal/oz) designed to meet the elevated energy needs of infants with conditions requiring additional calories for adequate growth and development. 1

Types and Composition of High Calorie Formulas

• Standard infant formulas typically provide 20 kcal/oz, while high calorie formulas start at 24 kcal/oz for newborns and can be increased to 30 kcal/oz or more for infants approaching 1 year of age 1
• Commercially available high calorie formulas include preterm formulas, preterm follow-up formulas, and specialized formulas with increased caloric density 1
• Nutritionally complete high calorie formulas contain balanced macronutrients (8-12% protein, 40-50% carbohydrate, and 40-50% fat) and appropriate micronutrients 1
• Energy- and protein-enriched formulas (EPEF) have been shown to improve weight gain in infants with poor growth due to various medical conditions 2

Methods to Create High Calorie Formulas

Commercial Options:

• Ready-to-use preterm formulas with higher caloric density 1
• Breast milk fortifiers that can be added to expressed breast milk 1, 3

Formula Concentration Methods:

• Adding modules of fat (long- or medium-chain triglycerides) to increase caloric density 1
• Adding carbohydrate modules (glucose polymers) to standard formulas 1
• Adding rice cereal (1 teaspoon per ounce increases caloric density by 5 kcal/oz) 1
• Adding blended avocado, which adds both calories and potassium 1

Clinical Applications

• High calorie formulas are indicated for infants with:

  • Chronic lung disease of infancy (CLDI) 1
  • Congenital heart disease 2
  • Poor weight gain or growth failure 3, 4
  • Increased metabolic demands due to illness 1, 3
  • Fluid restriction requirements 1

• Initial recommendation is to start with 120 kcal/kg/day to promote "catch-up" weight gain 1, 3

• For infants with higher energy requirements, intake may need to increase to 150 kcal/kg/day or more 1

Monitoring and Considerations

• Slow transition to calorically dense formulas improves tolerance 1

• Monitor for potential side effects:

  • Extra fat may decrease gastric emptying and contribute to gastroesophageal reflux 1
  • High fat content may lead to ketosis 1
  • Excess carbohydrates may cause loose, watery stools 1
  • Monitor stools for fat (qualitatively and quantitatively) in infants with loose, greasy stools 1
  • Test stools for reducing substances in infants receiving formulas with added carbohydrate 1

• When using high calorie formulas, regularly assess:

  • Weight, length, and head circumference to determine adequacy of nutritional support 3
  • Formula tolerance, including stool consistency and frequency 2
  • Signs of feeding difficulties 4

Important Considerations and Potential Pitfalls

• Excessive energy intake may occur with long-term use of formulas thickened with rice cereal (adding 1 tablespoon of rice cereal per ounce increases energy density from 20 to 34 kcal/oz) 1
• Protein intake should be maintained at appropriate levels (3 g/kg/day in early infancy to 1.2 g/kg/day in early childhood) 1
• Young infants should receive no more than 4 g/kg/day of protein due to risk of acidosis related to immature kidneys 1
• Micronutrient assessment is necessary, as high calorie formulas may need vitamin and mineral supplementation if less than 100% of the Recommended Dietary Allowance 1
• Formula enhancement with homemade recipes may have unstudied bioavailability and tolerance issues 5