Mifflin et al developed equations for predicting the resting energy expenditure (REE) in healthy adults. These are referred to by the authors as the Mifflin-St Jeor Equations (MSJE).
Population studied:
(1) healthy adults aged from 19 to 78 years of age, with a mean age of 45
(2) approximately equal numbers of men and women
(3) approximately half were of normal weight and half were obese
24 hour energy expenditure in kcal/day =
= (resting energy expenditure) + (thermic effects of food) + (physical activity)
where:
• resting energy expenditure = 65-70% of daily energy expenditure
• thermic effects of food = 10-15% of daily energy expenditures
• physical activity = 20-30% of daily energy expenditures
• thermic effects of food and physical activity tend to be variable
REE in females =
= (9.99 * (weight in kilograms)) + (6.25 * (height in centimeters)) - (4.92 * (age in years)) - 161
REE in males =
= (9.99 * (weight in kilograms)) + (6.25 * (height in centimeters)) - (4.92 * (age in years)) +5
The authors also found that fat free mass (FFM) and body weight alone could give estimates of the REE:
estimated REE in kcal =
= (19.7 * (fat free mass in kilograms)) + 413
estimated REE in kcal =
= (15.1 * (body weight in kilograms)) + 371
where:
• R^2 for fat free mass = 0.64
• R^2 for body weight = 0.56
