Basal Metabolic Rate — Schofield Equation
Schofield WN.
Predicting basal metabolic rate, new standards and review of previous work.
Hum Nutr Clin Nutr. 1985;39 Suppl 1:5–41.
(
PMID 4044297)
· Endorsed by FAO/WHO/UNU Expert Consultation, Technical Report Series 724 (1985).
BMR estimates (kcal/day), weight-based with height, by sex and age band:
Female 0–3 y: (16.252 × Wt) + (10.232 × Ht) − 413.5
Female 3–10 y: (16.969 × Wt) + (1.618 × Ht) + 371.2
Female 10–18 y: (8.365 × Wt) + (4.65 × Ht) + 200.0
Male 0–3 y: (0.167 × Wt) + (15.174 × Ht) − 617.6
Male 3–10 y: (19.59 × Wt) + (1.303 × Ht) + 414.9
Male 10–18 y: (16.25 × Wt) + (1.372 × Ht) + 515.5
Wt in kg, Ht in cm. Note: Schofield equations may overestimate BMR in some pediatric populations and are unsuitable for obese individuals.
Total Energy Expenditure
TEE = BMR × Activity Factor × Stress Factor × Catch-up Growth
Activity factors for habitual physical activity (PAL values) and hospitalized patients (bedridden 1.2 / ambulatory 1.3) follow standard clinical nutrition references.
See: FAO/WHO/UNU. Human energy requirements. Report of a Joint Expert Consultation. Rome, 2004.
Stress factors are condition-dependent multipliers from clinical nutrition practice (e.g. surgery, sepsis, burns, trauma). Values vary between institutions — verify against local protocol.
Catch-up Growth (Malnutrition / Wasting)
Catch-up factor = Ideal body weight ÷ Actual body weight
Ideal body weight taken as weight-for-height at the 50th centile.
See: WHO. Management of severe malnutrition: a manual for physicians and other senior health workers. Geneva: WHO, 1999.
Growth Assessment & Z-scores
WHO Multicentre Growth Reference Study Group.
WHO Child Growth Standards: length/height-for-age, weight-for-age, weight-for-length, weight-for-height and body mass index-for-age.
Geneva: WHO, 2006.
(
who.int)
— used for automatic growth assessment (0–5 y). The Thai 0–5 y charts (Pediatric Nutrition Association of Thailand / Siriraj) are built on this same standard.
Z-scores computed by the LMS method:
z = ((X/M)^L − 1) / (L·S), for L ≠ 0
where L, M, S are the sex- and age/height-specific parameters; M (median) is the 50th-centile (ideal) value.
Cole TJ, Green PJ. Smoothing reference centile curves: the LMS method and penalized likelihood. Stat Med. 1992;11:1305–1319.
5–19 y (Thai patients): National growth reference for children 5–19 years, 2020 (Bureau of Nutrition, Ministry of Public Health, Thailand). These charts are not embedded for automatic calculation — read the weight-for-height median from the chart and enter the ideal weight manually.
Maintenance Fluids — Holliday-Segar
Holliday MA, Segar WE.
The maintenance need for water in parenteral fluid therapy.
Pediatrics. 1957;19(5):823–832.
(
doi:10.1542/peds.19.5.823)
100 mL/kg/d (first 10 kg) + 50 mL/kg/d (10–20 kg) + 20 mL/kg/d (>20 kg)
Hourly rate ("4-2-1" rule) = daily volume ÷ 24.
Feld LG, Neuspiel DR, Foster BA, et al.
Clinical Practice Guideline: Maintenance Intravenous Fluids in Children.
Pediatrics. 2018;142(6):e20183083.
(
doi:10.1542/peds.2018-3083)
— supports isotonic maintenance fluids and clinical adjustment of rates.
Refeeding Syndrome
World Health Organization.
Guideline: Updates on the management of severe acute malnutrition in infants and children.
Geneva: WHO, 2013.
— basis for gradual caloric advancement, thiamine supplementation, and electrolyte monitoring (phosphate, potassium, magnesium).
Advancement schedule (start at a fraction of TEE, advance over several days) and monitoring recommendations are illustrative defaults derived from WHO SAM guidance and general refeeding-syndrome literature. They are not patient-specific — adapt to clinical context.
Caloric Distribution — Macronutrients
Protein DRI by age: WHO/FAO/UNU recommended protein intakes (g/kg/day):
6–11 months: 1.56 · 1–3 y: 1.20 · 4–8 y: 1.05 · 9–12 y: 1.10 · 13–15 y: 1.07 · 16–18 y: 1.05 · >19 y: 1.00.
Catch-up protein = DRI for age × (Ideal BW ÷ Actual BW)
Source: WHO. Protein and amino acid requirements in human nutrition. Technical Report Series 935. Geneva: WHO, 2007.
Fat distribution by age: 0–6 months: 40–60% TC · 6 mo–2 y: 35–40% TC · >2 y: 25–35% TC.
ESPGHAN / Academy of Nutrition and Dietetics Pediatric Nutrition Reference.
GERD: Low-normal fat preferred — fat delays gastric emptying and may worsen reflux symptoms.
Chronic lung disease: High-normal fat (35–45%) lowers the respiratory quotient (RQ = CO₂ produced ÷ O₂ consumed), reducing CO₂ production compared with carbohydrate oxidation. Particularly relevant in ventilated patients.
Talpers SS et al. Nutritionally associated increased carbon dioxide production. Chest. 1992;102(2):551–555.
Disclaimer: This tool is for clinical education and decision-support only. It does not replace clinical judgment, institutional protocols, or specialist advice. All calculations should be independently verified before being applied to patient care. Equation values may differ slightly between published sources and editions.