College of Nursing
NCM 105A
NUTRITION AND DIET THERAPY
LABORATORY
LABORATORY EXERCISE NO. 3
Dietary Computation: Desirable Body Weight Determination
Name: _________________________________________________________ Date Due: _________________________
Year and Section: ______________________________________________ Date Submitted: ____________________
Professor: ______________________________________________________ Score: _____________________________
I. Objectives:
Within the week, the student will be able to:
1. Define Desirable Body Weight
2. Compute Desirable Body Weight of different age groups using various formulas
II. Procedure:
Desirable Body Weight (DBW) is also termed ideal or reference weight but more appropriately
called healthy weight. In children, ideal weight is the midpoint of the recommended weight range at a
specified age.
Recently, authorities emphasize that the most important factor in weight is body composition.
Thus, the term healthy weight has replaced ideal weight, indicating that a person’s body composition has a
good balance between lean body mass and fat tissue.
In adolescent and adults, however, DBW refers to the average recommended weight range at
a specified height for a given body frame; it is weight found statistically to be most compatible with health
and longevity.
When calculating the DBW, it is generally recommended to round it off to the nearest whole
number except for infants.
A. Infants:
a. 1-6 months
DBW (gm) = birth weight (gm) + (Age in mo. X 600)
7-12 months
DBW (gm) = birth weight (gm) + (Age in mo. X 500)
Note: If the birth weight is unknown, allow 3000 gm (full term) or 2500 gm (premature). One kilo is
2.2 pounds.
Exercise 3.1 Birth weight= 3500 gm, 6-month old infant
b. DBW (k)=age (mo.) ÷ 2 + 3
Exercise 3.2 6 month-old infant
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B. Children
DBW (k) = (age in years x 2) + 8
Exercise 3.3 7-year old child
Note: Add 2 kilos for each year
C. Adolescents/ Adults
a. NDAP Method
Step 1. Allow 112 pounds for 5 feet tall (men)
Allow 106 pounds for 5 feet tall (women)
Step 2. Then: add (subtract) 4 pounds for every inch above (below) 5 feet.
Conversion aid:
1 kilo= 2.2 lb
1 foot= 12 inches
1 inch= 2.54 cm
Exercise 3.4 64”tall male subject (64”=5’4”)
Exercise 3.5 4’11” female subject
b. Tannhauser’s Method (Broca index)
Step 1. DBW (k)= Height (cm)-100
Step 2. Deduct 10%= (To apply this method for Filipinos whose statures are usually small, unless
body frame is identified).
Exercise 3.6 5’2” female subject
c. Using the BMI-derived formula
Men: DBW (k) = height in meters² x 22.0
Women: DBW (k) = height in meters² x 20.8
Conversion aid:
1 m= 100 cm
Exercise 3.7 5’5” male
d. Using the Hamwi formula (adults only)
Females:
100 lb for first 5 ft
Add 5 lb for each additional inch
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Males:
106 lb for first 5 ft
Add 6 lb for each additional inch
Adjustments:
Small frame- subtract 10%
Large frame: add 10%
D. Estimating DBW of Amputees
1. Compute DBW (in pounds or in kilos) by age and sex using any method.
2. Adjust DBW according to type of amputation
Amputation DBW= DBW- (DBW x % total body weight amputated)
Body Part % of Total Body Weight
Hand 0.3
Forearm and Hand 2.6
Entire arm 6.2
Foot 1.7
Below- knee Amputation (BKA) 7.0
Above-knee Amputation (AKA) 11.0
Entire Leg 18.6
Exercise 3.8 5’2” woman, 25 y/o with BKA (use NDAP Method)
Exercise 3.9 72” tall bachelor with bilateral amputation of the feet
Note: 72 inches= 6 feet
% total body weight amputated= 1.7 x 2 (bilateral)
= .034
E. Adjusting DBW According to Body Frame (Adolescents and Adults)
Desirable body weight of teens and adults is more precisely estimated when body frame is
considered. To determine a person’s body frame, try using the technique below.
Body Frame According to Wrist Size
Technique: Wrap the fingers of one hand around the opposite wrist.
Frame Size
If the thumb and middle finger overlap by 1 cm Small
If the thumb and middle finger touch Medium
If the thumb and middle finger cannot touch by 1 cm Large
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Build Adjustment DBW Range
Small Less 10% of computed DBW ± 10% of adjusted DBW
Medium As computed ± 10% of adjusted DBW
Large Add 10% of computed DBW ± 10% of adjusted DBW
Exercise 3.10 5’10” Male using NDAP Formula, Large Frame
Exercise 3.11 Compute for your DBW using the three methods. Adjust DBW if it is necessary depending on
your body frame.
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