Dietary Computation
Dietary Computation
Dietary Computation
BASAL METABOLISM
Is the measure of energy needed by the body at rest for all its internal chemical activities Also known as Required Energy Expenditure (REE)
Harris-Benedict formula (use of weight, height, age and sex) REE = 66 + [13.7 x wt(kg)] + [5 x ht(cm)] [6.8 age(yr)] REE = 655 + [9.6 x wt(kg)] + [1.8 x ht(cm) [4.7 x age (yr)]
15
20 25 30
7.6
9.5 12.1 12.8
35
40 45 50
14.4
15.9 17.4 18.8
65
70 80 90
21.6
24.2 26.7 29.2
100
31.6
Sex
Women have a metabolism of 5-10% lower than men when they are of the same weight and height.
Age
Metabolic rate is highest during periods of rapid growth (1st and 2nd year of life) Peak through the ages of puberty and adolescence BMR declines slowly with increasing age
Body composition
Large adipose tissue = lowers BMR Muscular development = increase in BMR
State of nutrition
Starvation/undernourishment = lowers BMR as much as 50 % below normal
Sleep
BMR falls approximately 10-15% than of waking levels.
Endocrine glands
Secretion of endocrine glands are the principal regulators of the Metabolic rate.
Fever
Increases the BMR about 7% for each degree rise in the body temperature above 78.6 F.
Age
for every 5 years between 25 to 50 years, 2 lbs additional
Tannhausers Method
Height in cm 100 cm Take 10% of the remainder and subtract the answer from the remainder Example:
DBW of 45 years old male, 54 tall Height = 54 = 64 inches = 162.56 cm 162.56 cm 100 cm = 62.56 10% of 62.56 cm = 6.256 62.56-6.256 = DBW (kg) 56.7 kg = DBW 126 lbs = DBW
Method I
Based on desirable body weight (DBW) according to occupation; often used in clinics and hospitals. Example:
50 kg man doing moderate activities 50 kg x 40 (moderate work see chart) = 2400 kcal/day
Occupation or activity
Male kcal/kg 14 16 18 20 30 35 40 44
60-60
70-79
2060
1810
1540
1340
Heavy
Very Heavy
2.1
2.4
1.9
2.2