Caloric Requirements by Age
| Age group |
Requirement |
Notes |
| 0–6 months |
100–120 kcal/kg/day |
~500–600 kcal/day total [1] |
| 6–12 months |
80–100 kcal/kg/day |
~700–850 kcal/day total [1] |
| Preterm infants |
110–130 kcal/kg/day |
For catch-up growth [2] |
| Toddlers (1–3 yr) |
80–100 kcal/kg/day |
| Preschool (4–6 yr) |
70–90 kcal/kg/day |
| School-age (7–12 yr) |
55–75 kcal/kg/day |
| Adolescents |
40–55 kcal/kg/day |
| Critically ill (sepsis, trauma, major burns) |
1.2–1.5× baseline; up to 1.5–2× in severe illness |
Calculate targets in WHO Calories →
Metabolic Rate Estimation (Schofield)
The Schofield equations estimate basal metabolic rate (BMR) directly from weight when a more granular estimate than age-based ranges is needed [5].
| Group |
Equation (BMR, kcal/day) |
| Males, 3–10 yr |
22.7 × weight (kg) + 495 |
| Males, 10–18 yr |
17.5 × weight (kg) + 651 |
| Females, 3–10 yr |
22.5 × weight (kg) + 499 |
| Females, 10–18 yr |
12.2 × weight (kg) + 746 |
Multiply BMR by an activity factor (1.3–1.5 in illness) and an injury factor (1.0–1.5 with fever or sepsis) to obtain total energy expenditure.
Calculate BMR in Schofield BMR →
Parenteral Nutrition Macronutrients
Protein [3]
| Group |
Goal dose |
| 0–6 months |
2.5–3 g/kg/day |
| 6–12 months |
2–2.5 g/kg/day |
| Toddlers |
1.5–2 g/kg/day |
| Older children |
1–1.5 g/kg/day |
| Critically ill |
1.5–2 g/kg/day |
| Renal failure |
0.8–1 g/kg/day |
Start at 0.5–1 g/kg/day and advance by 0.5–1 g/kg/day daily to reach goal by day 3–4 [3].
Dextrose (3.4 kcal/g)
| Timing |
Dose |
| Newborn, day 1 |
4–6 g/kg/day (prevents hypoglycemia) [4] |
| Day 2–3 |
8–10 g/kg/day |
| Day 4+ |
10–14 g/kg/day, kept ≤12–14 to avoid hyperglycemia |
| Older children |
5–10 g/kg/day, advanced gradually |
Concentrations above 12.5% require central venous access.
Lipids (9 kcal/g)
| Step |
Dose |
| Start |
0.5–1 g/kg/day |
| Advance |
+0.5–1 g/kg/day per day |
| Goal |
2–3 g/kg/day (up to 4 g/kg/day in neonates) |
Infuse over 12–24 hours to limit hypertriglyceridemia. Check triglycerides weekly at doses above 3 g/kg/day. Cyclic lipid infusion (8–12 hours) is an option in stable patients [3].
Caution. Advancing dextrose or protein directly to goal on day 1 in a neonate can precipitate hyperglycemia or metabolic intolerance. Titrate stepwise as above rather than starting at target.
Calculate goal doses in TPN Macros →
Glucose Infusion Rate
GIR quantifies the rate of glucose delivery per kilogram per minute:
GIR = (g dextrose/kg/day) / 1.44
| GIR (mg/kg/min) |
Interpretation |
| 2–4 |
Early support |
| 4–7 |
Standard for preterm infants |
| 7–12 |
Full nutritional support for growing preterm infants |
| >12 |
Risk of metabolic complications |
Rates above 12–14 mg/kg/min shift metabolism toward lipogenesis, produce hepatic steatosis, and increase CO₂ production, which can impair ventilator weaning.
Clinical pearl. A neonate on 12 g/kg/day of dextrose has a GIR of 12 / 1.44 = 8.3 mg/kg/min, within the full-nutrition range for a growing preterm infant.
Calculate GIR →
Breast Milk Fortification
Mature breast milk provides approximately 65–70 kcal/100 mL (about 20 kcal/oz). Preterm infants require approximately 80 kcal/100 mL (24 kcal/oz) for adequate growth [2].
- Powder fortifiers add approximately 4 kcal/100 mL.
- Liquid fortifiers allow more flexible dosing.
- Modular fortifiers allow independent adjustment of protein, fat, and carbohydrate when standard fortification is insufficient.
Target weight gain in fortified preterm infants is 15–20 g/kg/day [2]. If this target is not met, increase fortification or add supplemental feeds.
Monitoring Parameters
- Set calorie targets using WHO-based ranges [1] or Schofield BMR [5].
- Advance TPN stepwise; avoid abrupt increases in protein, dextrose, or lipid dose.
- Maintain neonatal blood glucose at 60–150 mg/dL; consider reducing GIR if glucose exceeds 150–180 mg/dL [4].
- Check triglycerides weekly when lipid dose exceeds 3 g/kg/day.
- Check prealbumin and transferrin every 1–2 weeks.
- Transition to enteral feeds as early as feasible to preserve gut function [2].
- Reassess nutritional targets weekly and with any change in clinical status.
References
- FAO/WHO/UNU. Human energy requirements: report of a joint FAO/WHO/UNU expert consultation. Food Nutr Bull. 2005;26(1):166.
- Embleton ND, Moltu SJ, Lapillonne A, et al. Enteral Nutrition in Preterm Infants (2022): A Position Paper From the ESPGHAN Committee on Nutrition. J Pediatr Gastroenterol Nutr. 2023;76(2):248-268. doi:10.1097/MPG.0000000000003642
- Koletzko B, Goulet O, Hunt J, et al. Guidelines on Paediatric Parenteral Nutrition of ESPGHAN and ESPEN. J Pediatr Gastroenterol Nutr. 2005;41 Suppl 2:S1-S87. doi:10.1097/01.mpg.0000181841.07090.f4
- Adamkin DH, Committee on Fetus and Newborn. Postnatal glucose homeostasis in late-preterm and term infants. Pediatrics. 2011;127(3):575-579. doi:10.1542/peds.2010-3851
- Schofield WN. Predicting basal metabolic rate, new standards and review of previous work. Hum Nutr Clin Nutr. 1985;39 Suppl 1:5-41.