II. Protocol: Step 1 - Estimate Resting Energy Expenditure (REE)
- Based on Mifflin-St Jeor Equation
- Males Resting Energy Expenditure
- Start: 10 x (Weight in kilograms) + 5
- Add: 6.25 x (Height in centimeters)
- Subtract: 5 x (Age in years)
- Females Resting Energy Expenditure
- Start: 10 x (Weight in kilograms) - 161
- Add: 6.25 x (Height in centimeters)
- Subtract: 5 x (Age in years)
III. Protocol: Step 2 - Estimate Daily Caloric Need
- Consider Activity factor (AF) of 1.0
- AF >1.0 grossly overestimates caloric needs
- Using activity factor of 1.0 may be weight neutral
- Mucha (2007) HP Primary Care Medicine, Lecture
- Bezera (2001) J Amer Dietetic Assoc 101 [PubMed]
- Determine Daily Caloric Need
- Resting Energy Expenditure x Activity Factor
- See Daily Energy Allowances
- Moderately active adolescents (e.g. teen athletes) may have high energy requirements to sustain activity, growth
- Females may require 2200 kcals/day, while males may require 2800 kcals/day
IV. Protocol: Step 3 - Calculate Adjusted Caloric Intake (for intentional weight loss)
- Determine daily caloric deficit (typically 250 to 500 kcals/day)
- Deficit of 500 Kcals/day = 3500/week (1 pound/week)
- See precautions below regarding over-estimation of weight loss with 3500 calorie/pound rule
- Determine Adjusted Caloric Intake
- Daily Caloric Need - Daily caloric Deficit (500)
- Do not lower intake below 1000 Kcals/day
- Consider using REE x0.8 for weight loss program
- Mucha (2007) HP Primary Care Medicine, Lecture
- Bezera (2001) J Amer Dietetic Assoc 101 [PubMed]
- Consider calorie intake goal based on body weight range
- Body weight <200 pounds: 1000 Kcals/day (500 kcal deficit per day)
- Body weight 200-249 pounds: 1200 Kcals/day (750 kcal deficit per day)
- Body weight 250-299 pounds: 1500 Kcals/day (1000 kcal deficit per day)
- Body weight 300-349 pounds: 1800 Kcals/day (1250 kcal deficit per day)
- Body weight >350 pounds: 2000 Kcals/day (1500 kcal deficit per day)
- Klein (2002) 123(3): 882-932 [PubMed]
V. Precautions: Over-estimation of weight loss with 3500 calorie/pound rule
- Weight loss estimates based on 3500 calorie deficit per pound weight loss will markedly overestimate loss
- Naive weight loss approximation with 3500 calorie rule (due to compensatory mechanisms)
- For every 100 calorie deficit, expect 10 pound weight loss over time
- Year 1: Weight loss of 50% of total estimate (5 pounds per 100 calorie deficit/day)
- Year 3: Weight loss of 95% of total estimate (9.5 pounds per 100 calorie deficit/day)
- Resources
- FPnotebook Resting Energy Expenditure Calculation
- NIH Body Weight Simulator
- References