Teaching Pediatric Nutrition to Residents: A Comprehensive Curriculum
Pediatric residents must master energy requirement calculations using Schofield's equations for resting energy expenditure (REE), understand age-specific macronutrient distributions (particularly the critical 30-40% fat requirement in infants under 2 years), and recognize that caloric needs vary dramatically by age, activity level, and clinical status—ranging from 90-120 kcal/kg/day in premature infants to 30-55 kcal/kg/day in adolescents. 1
Core Calculation Methods for Energy Requirements
Schofield's Equations for REE (Preferred Method)
Use Schofield's weight-based equations as the foundation for calculating resting energy expenditure, as these are least likely to underestimate actual needs compared to measured values. 1
Ages 0-3 years:
Ages 3-10 years:
Ages 10-18 years:
Adjusting REE for Total Energy Needs
After calculating REE, multiply by activity factors: sedentary children require minimal adjustment, moderately active children need an additional 0-200 kcal/day, and very active children require an additional 200-400 kcal/day. 1
For catch-up growth in malnourished children, use this formula: (RDA for chronological age in kcal/kg × ideal weight for height) ÷ actual weight. 1
Age-Specific Energy Requirements
Premature Infants (Critical First Days)
On day 1 of life, provide at least 45-55 kcal/kg/day to meet minimal energy requirements, then advance to 90-120 kcal/kg/day to approximate intrauterine lean body mass accretion. 1
- Target weight gain: 17-20 g/kg/day to prevent growth failure 1
- Energy cost includes both expenditure (45-55 kcal/kg/day) and tissue synthesis 1
- Inadequate early nutrition leads to impaired neurodevelopment and increased disease severity 1
Full-Term Infants (0-12 Months)
Healthy full-term infants require 75-85 kcal/kg/day in the acute phase, 60-65 kcal/kg/day when stable, and 45-50 kcal/kg/day during recovery. 1
- Expected weight gain: 210 grams/week (30 g/day) from 0-3 months, then 140 grams/week (20 g/day) from 3-6 months 2
- Birth weight should be regained by 10-14 days; failure to do so requires immediate evaluation 2
- Weight gain below 17-20 g/kg/day represents inadequate growth requiring intervention 2
Toddlers (1-3 Years)
Children aged 1-3 years require 65-75 kcal/kg/day when stable, with total daily intake of 900-1,300 kcal depending on activity level. 1, 3
- Sedentary: 900-1,000 kcal/day 1, 3
- Moderately active: 1,000-1,200 kcal/day 3
- Active: 1,200-1,300 kcal/day 3
School-Age Children (4-8 Years)
Children aged 4-8 years require 55-60 kcal/kg/day when stable, with total daily intake of 1,200-1,800 kcal based on gender and activity. 1
Pre-Adolescents (9-13 Years)
Children aged 9-13 years require 40-55 kcal/kg/day when stable, with total intake of 1,400-2,600 kcal/day. 1, 4
- Girls sedentary: 1,400-1,600 kcal/day 4
- Girls active: 1,800-2,200 kcal/day 4
- Boys sedentary: 1,600-2,000 kcal/day 4
- Boys active: 2,000-2,600 kcal/day 4
Adolescents (14-18 Years)
Adolescents require 25-40 kcal/kg/day when stable, with total intake of 1,800-3,200 kcal/day depending on gender and activity. 1
Macronutrient Distribution by Age
Infants Under 12 Months
Fat intake should NOT be restricted in infants under 12 months due to critical roles in brain and cognitive development. 1
- Fat: 40-50% of total calories 1
- Carbohydrate: 40-50% of total calories 1
- Protein: 8-12% of total calories 1
Children 1-3 Years
Fat should comprise 30-40% of total calories, with transition to reduced-fat milk after age 2 years based on growth trajectory and cardiovascular risk. 1
Children 4-18 Years
Fat should comprise 25-35% of total calories, with saturated fat limited to <10% and trans fats minimized. 1
- Fat: 25-35% of calories 1
- Protein: 15-20% of calories 1
- Carbohydrate: 50-55% of calories 1
- Fiber: age + 5 grams/day for young children, up to 14 g/1000 kcal for older children 1
Specific Macronutrient Recommendations
Emphasize monounsaturated and polyunsaturated fats (20% of fat intake), limit saturated fats, and eliminate trans fats. 1
- Use fat-free milk after age 2 years to optimize nutrient intake without excess saturated fat 1
- Consume fish twice weekly for omega-3 fatty acids 1
- Choose whole grains for at least half of grain intake 1, 4
Parenteral Nutrition Considerations
Glucose Administration in PN
The amount of glucose in parenteral nutrition must balance meeting energy needs against risks of overfeeding, considering phase of illness (acute/stable/recovery), and glucose from all sources including medications. 1
Glucose Dosing by Weight
For critically ill children, glucose dosing varies by weight and illness phase: 1
- <10 kg: Acute phase 2-5 mg/kg/min, stable phase 5-7 mg/kg/min, recovery 7-9 mg/kg/min 1
- 10-45 kg: Acute phase 1-3 mg/kg/min, stable phase 3-5 mg/kg/min, recovery 5-7 mg/kg/min 1
- >45 kg: Acute phase 0.5-1 mg/kg/min, stable phase 1-2 mg/kg/min, recovery 2-3 mg/kg/min 1
Critical Glucose Management
Avoid hyperglycemia >8 mmol/L (145 mg/dL) in both PICU and NICU patients due to increased morbidity and mortality. 1
- Treat repetitive glucose >10 mmol/L (180 mg/dL) with continuous insulin infusion in PICU patients 1
- In neonates, treat glucose >10 mmol/L with insulin only after adjusting glucose infusion rate 1
- Avoid repetitive/prolonged hypoglycemia <2.5 mmol/L (45 mg/dL) in all ICU patients 1
Consequences of Glucose Overfeeding
Excessive glucose intake causes hyperglycemia, increases lipogenesis with hepatic steatosis, elevates VLDL triglycerides, and increases CO2 production with higher minute ventilation. 1
Glucose intake does NOT reduce protein catabolism during acute critical illness. 1
Timing of Parenteral Nutrition in Critical Illness
In previously well-nourished critically ill children, withholding parenteral nutrition for up to 1 week while providing micronutrients reduces infections, enhances recovery, and decreases ICU-acquired weakness. 1
- Early PN (within 24 hours) does not prevent muscle wasting but increases adipose tissue deposition 1
- During acute phase, endogenous energy production provides majority of needs regardless of exogenous intake 1
- After acute phase (typically 1-2 days), increase energy intake to 1.3 times REE for growth and catch-up growth 1
Energy Calculations Using Atwater Factors
Standard Atwater Factors (Clinical Practice)
Use simplified Atwater factors for clinical calculations: protein and carbohydrate provide 4 kcal/g, fat provides 9 kcal/g. 1
Differences Between Enteral and Parenteral Sources
Recognize that actual metabolizable energy differs between routes: 1
- Amino acids: 3.75 kcal/g when oxidized to urea, 4.75 kcal/g when stored as protein 1
- Glucose: 3.75 kcal/g (lower than complex carbohydrates at 4.2 kcal/g) 1
- Intravenous lipid emulsions: ~10 kcal/g including glycerol content 1
- Enteral nutrition requires 10-20% higher energy intake than parenteral due to splanchnic metabolism 1
Special Clinical Scenarios
Chronic Lung Disease of Infancy
Infants with chronic lung disease require 120-150 kcal/kg/day or more due to increased metabolic rates and diminished oxygen transfer capacity. 1
- Start with 24 kcal/oz formula, advance to 30 kcal/oz or higher as infant approaches 1 year 1
- Maintain oxygen saturation >95% to keep pulmonary vascular resistance low and reduce energy requirements 1
- Add fat modules (MCT or LCT) or carbohydrate modules (glucose polymers) to increase caloric density 1
- Target macronutrient balance: 8-12% protein, 40-50% carbohydrate, 40-50% fat 1
Type 1 Diabetes
Individualized medical nutrition therapy is essential, with carbohydrate monitoring (counting or experience-based estimation) as the key to optimal glycemic control. 1
- Consistency in carbohydrate counting matters more than absolute accuracy 1
- Over/under-calculating by 10-15 g carbohydrate is unlikely to cause significant glycemic excursions 1
- Comprehensive nutrition education at diagnosis with annual updates by experienced dietitian 1
- Assess caloric intake relative to weight status and cardiovascular risk factors 1
Critically Ill Children
Energy requirements during critical illness vary by phase: acute phase requires energy equal to or lower than measured expenditure, stable phase requires REE-based intake, recovery phase requires 1.3 times REE. 1
- Acute phase: Do not exceed measured energy expenditure 1
- Stable phase: Use Schofield equations or indirect calorimetry 1
- Recovery phase: Increase to 1.3 × REE for catch-up growth 1
- Prediction equations frequently fail to accurately estimate expenditure in critically ill children 1
Practical Food Group Servings
Daily Servings by Age (American Heart Association)
Teach residents these specific daily serving targets: 1, 4
Ages 1-3 years: 1
- Milk/dairy: 2 cups (2% fat for 1-year-olds, transition to fat-free after age 2) 1
- Lean meat/beans: 2 oz 1
- Fruits: 1 cup 1
- Vegetables: 1 cup 1
- Grains: 3 oz (half whole grains) 1
Ages 4-8 years: 1
- Milk/dairy: 2 cups (fat-free) 1
- Lean meat/beans: 3-4 oz 1
- Fruits: 1.5 cups 1
- Vegetables: 1.5 cups 1
- Grains: 4 oz (half whole grains) 1
Ages 9-13 years: 4
- Milk/dairy: 3 cups (fat-free or low-fat) 4
- Lean meat/beans: 5 oz 4
- Fruits: 1.5 cups 4
- Vegetables: 2.5 cups (variety from all subgroups) 4
- Grains: 5-6 oz (at least half whole grains) 4
Ages 14-18 years: 1
- Milk/dairy: 3 cups (fat-free or low-fat) 1
- Lean meat/beans: 5-6 oz 1
- Fruits: 1.5-2 cups 1
- Vegetables: 2-3 cups 1
- Grains: 5-7 oz (at least half whole grains) 1
Critical Pitfalls to Avoid
Overfeeding Risks
Excessive energy intake, particularly from glucose, causes hyperglycemia, hepatic steatosis, increased CO2 production, and does not reduce protein catabolism in acute illness. 1
- Monitor for hyperglycemia >8 mmol/L (145 mg/dL) in all critically ill patients 1
- Avoid adding stress factors to REE calculations without evidence 1
- Recognize that early aggressive PN in critical illness may worsen outcomes 1
Underfeeding Risks
Inadequate energy provision limits growth because protein is diverted to energy metabolism rather than tissue accretion, and is associated with impaired immunity and increased morbidity/mortality. 1
- Weight gain <17-20 g/kg/day in infants requires immediate intervention 1, 2
- Failure to regain birth weight by 12-14 days mandates evaluation 2
- Inadequate early nutrition in premature infants impairs neurodevelopment 1
Fat Restriction Errors
Never restrict fat intake in infants under 12 months without medical indication due to critical roles in brain and cognitive development. 1
- Infants require 40-50% of calories from fat 1
- Transition to reduced-fat milk only after age 2 years based on individual growth and risk factors 1
Calculation Errors
Do not use CDC growth charts for infants under 24 months—WHO charts represent optimal growth patterns and are the gold standard. 2
- Schofield equations using weight and height are preferred over weight-only equations 1
- Prediction equations may not reliably estimate energy expenditure in critically ill children 1
- Indirect calorimetry is optimal when available for mechanically ventilated children 1
Glucose Management in Critical Illness
Glucose metabolism is profoundly altered during acute critical illness, with loss of normal substrate utilization control. 1
- Hyperglycemia during acute illness is as undesirable as hypoglycemia 1
- Use blood gas analyzers rather than point-of-care glucometers for accuracy 1
- Account for glucose from all sources including medications 1
Monitoring and Assessment
Growth Monitoring
Regular monitoring of weight, height, and BMI is essential, with growth following established percentile curves. 3
- Dramatic changes in percentiles indicate potential nutritional issues 3
- Weight gain of 17-20 g/kg/day represents appropriate trajectories for young children 3
- Schedule weight checks within 48-72 hours after nutritional interventions 2
Nutritional Assessment at Diagnosis
Detect malnourished patients at admission as they are most vulnerable and benefit most from timely intervention. 5