When estimating caloric requirements for pediatric patients, what are the preferred equations (Schofield, World Health Organization (WHO), Pediatric Dietary Reference Intake (PDRI)) for different age groups, weights, and medical conditions, such as impaired renal function or critical illness?

Selecting Energy Estimation Equations for Pediatric Patients

Primary Recommendation

The Schofield equation using both weight and height is the preferred method for estimating resting energy expenditure (REE) across most pediatric populations and clinical conditions, as it is least likely to underestimate REE compared to measured values. 1, 2, 3

Algorithm for Equation Selection by Clinical Setting

Critically Ill Children (PICU/ICU)

• First-line approach: Measure energy expenditure directly using indirect calorimetry whenever feasible, as this is the gold standard for mechanically ventilated and critically ill children 1, 2, 4
• When indirect calorimetry unavailable: Use Schofield weight-height equation as the backup method 1, 2
• Acute phase (first 1-2 days): Provide 60-85 kcal/kg/day depending on age, which approximates REE without adding activity or stress factors 1, 2
• Stable/recovery phase: Multiply calculated REE by 1.3 to account for tissue repair and growth 1, 2
• Major burns specifically: Schofield equation is explicitly advocated for pediatric burn patients 1

Critical caveat: Prediction equations have poor accuracy in critically ill children—no equation achieves >50% accuracy within ±10% of measured values 4. The Schofield and Talbot tables perform best but still only achieve ~50% accuracy within ±15% of measured values 4.

General Pediatric Ward and Outpatient Settings

• Use Schofield weight-height equation for calculating REE in stable hospitalized children and outpatients 1, 5, 2, 6
• Calculate total energy expenditure (TEE): REE × physical activity level (PAL) + growth energy needs 5, 2
• Physical activity factors: Sedentary/hospitalized PAL = 1.2-1.3; light activity PAL = 1.5; moderate activity PAL = 1.7; vigorous activity PAL = 2.0 5, 2
• Growth energy additions: 20 kcal/day for ages 6-12 months and prepubertal children; 30 kcal/day during peak pubertal growth 5

Failure to Thrive and Malnutrition

• Measure REE by indirect calorimetry when knowledge of precise caloric needs is required for optimal clinical care, particularly in young infants (birth to 3 years) with moderate to severe failure to thrive 1, 3
• When measurement unavailable: Use Schofield weight-height equation, as it is least likely to underestimate REE in this population 1, 3
• For catch-up growth: Calculate energy requirements based on ideal weight for height age (not chronological age) plus additional allowance for accelerated growth 2

Important warning: Younger age and more severe growth failure are associated with underestimation of REE by all prediction equations 3. The Schofield weight-height equation predicted REE accurately in only ~40% of children with failure to thrive 3.

Pediatric Obesity

• Use Schofield weight-height equation with actual body weight (not ideal body weight), as body weight is the main predictor of energy expenditure and the equations were developed using actual weight 5
• Create caloric deficit: Subtract 500-750 kcal/day from calculated TEE to achieve ~0.5 kg weight loss per week 5
• Minimum intake threshold: Never allow intake to fall below 900 kcal/day, even under medical supervision 5

Parenteral Nutrition

• Use Schofield equation to calculate REE, then apply age-specific energy targets 1
• Premature infants: 45-55 kcal/kg/day on first day of life; 90-120 kcal/kg/day after initial weight loss to approximate intrauterine growth 1
• Stable patients: Total parenteral energy can be calculated by doubling resting energy requirements 1

Why NOT to Use WHO or Other Equations

WHO Equation Limitations

• The WHO equation shows similar mean bias to Schofield at the population level but has larger individual variability 7
• Current ESPGHAN/ESPEN guidelines explicitly moved away from 1985 FAO/WHO/UNU recommendations to 2004 recommendations, resulting in substantially lower energy recommendations 1
• The Schofield equation outperforms WHO in preventing underestimation of REE 1, 3

Harris-Benedict Equation Limitations

• Harris-Benedict significantly overestimates REE, predicting only 92% ± 25% of measured values compared to Schofield's 100% ± 19% 8
• It overestimates REE in approximately two-thirds of critically ill children 4
• It is less accurate than Schofield across all pediatric age groups 8

Oxford Equation Limitations

• While showing small mean bias at population level, the Oxford equation has large standard deviation of bias, making it inaccurate for individual patients 7

Specific Schofield Equations by Age

Ages 0-3 years:

• Boys: REE (kcal/day) = 59.5 × (weight in kg) + 30 1, 6
• Girls: REE (kcal/day) = 58.3 × (weight in kg) + 31 1, 6

Ages 3-10 years:

• Boys: REE (kcal/day) = 22.7 × (weight in kg) + 504 1, 5
• Girls: REE (kcal/day) = 20.3 × (weight in kg) + 486 1, 5

Ages 10-18 years:

• Boys: REE (kcal/day) = 17.7 × (weight in kg) + 658 1, 5
• Girls: REE (kcal/day) = 13.4 × (weight in kg) + 692 1, 5

Common Pitfalls to Avoid

• Do not add arbitrary stress factors to Schofield-calculated REE in critically ill children, as this leads to overfeeding 1
• Do not rely solely on prediction equations in children with suspected metabolic problems, severe malnutrition, or when initial nutritional interventions fail—measure REE directly 1, 2
• Do not use weight-only equations when height is available, as the weight-height Schofield equation consistently outperforms weight-only versions 1, 8, 3
• Recognize inherent inaccuracy: Even the best prediction equations (Schofield) are accurate within ±10% in fewer than 50% of individual patients 4, 7, 8