Body Composition—Activity 1
Name ________________________________________________ Date _________________ Class Period ___________
How Much Body Fat Do You Need?
Body composition is the proportion of fat, muscle, bone, connective
tissue, and water that make up body weight. There is no single ideal body
weight. Many people place too much emphasis on how much they weigh.
The more important factor is the amount of lean body weight or percentage
of body fat of an individual. Lean body weight is the combined weight of
bone, muscle, water, and connective tissue. Each person needs some body
fat to pad or protect the body and to use some vitamins in the body. It is
important to be at a healthy percentage of body fat. Being too lean or too
fat has associated health risks. Males at a healthy level would be between
7% and 19% body fat, while females would be between 12% and 24%.
Figure 6.1 shows calculations for measuring body fat.
Figure 6.1
Your body fat weight Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
Your percentage
of body fat
Your total
body weight
Your lean
body weight
Your body fat
weight
Your total
body weight
Individuals who have a high percentage of body fat are at risk for
being obese with the associated diseases, such as cardiovascular disease,
hypertension, and diabetes. Individuals who are too lean may delay or
affect puberty. They may also be malnourished, lacking vitamins and
minerals for good health.
Physical activity and exercise can help keep body fat at a proper level
because when you are active and move your body, you burn or expend
energy. The source of energy is found in calories from the foods you eat.
Calories that are not burned become stored by the body as fat.
Fitness Zone Online Body Composition
Body Composition—Activity 1
Name ________________________________________________ Date _________________ Class Period ___________
Sometimes the Body Mass Index Scale (BMI) is used to provide
information using your height and weight to determine where you fit
on a chart. For many people, the BMI provides an accurate assessment.
However, for someone who is very muscular, the BMI scale may falsely
indicate they are overweight. The greater weight is due to muscle mass,
not body fat. Figure 6.2 below illustrates a BMI for males and females.
Figure 6.2
30
28
26
BMI
24
22
le
enti
erc
th P
95
ile
nt
erce
P
th
85
20
ntile
18
16
32
May be
overweight
28
May be
at risk of
overweight
Range of
appropriate
weight
26
24
5
12
14 15 16 17 18
AGE
Fitness Zone Online Body Composition
95
ntile
e
Perc
85th
May be
overweight
May be
at risk of
overweight
Range of
appropriate
weight
20
16
May be
underweight
erce
th P
22
18
erce
th P
14
ntile
30
BMI
32
BMI Chart for Females
ntile
erce
5th P
14
12
14 15 16 17 18
AGE
May be
underweight
Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
BMI Chart for Males
Body Composition—Activity 1
Name ________________________________________________ Date _________________ Class Period ___________
Body Mass Index Activity
The purpose of this activity is to determine your own BMI using
mathematical calculations rather than looking on a chart.
Determine Your BMI
STEP 1: Your weight × 0.45 = _____________
STEP 2: Your height (in inches) × 0.025 = _____________
STEP 3: Multiply the answer of STEP 2 by itself _____________ × _____________ = _____________
STEP 4: Divide your answer in STEP 1 by your answer in STEP 3
_____________ ÷ _____________ = _____________ Body Mass Index
STEP 5: Refer to your age and BMI in the above chart.
EXAMPLE
Female who is 4’8” (56 inches), weighs 98 pounds, and is 15 years old.
STEP 1: (Weight) 98 × 0.045 = 44.1
STEP 2: (Height) 56 × 0.025 = 1.4
STEP 3: (Answer of STEP 3) 1.4 × 1.4 = 1.96
STEP 4: (Answer of STEP 1) 44.1 ÷ (Answer of STEP 3) 1.96 = 22.5 Body Mass Index
STEP 5: This female is in her range of appropriate weight.
Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
What is your BMI? Where do you fall on the BMI chart?
___________________________________________________________________________________
___________________________________________________________________________________
Do you think the BMI shows an accurate picture of your health? Why?
___________________________________________________________________________________
___________________________________________________________________________________
Fitness Zone Online Body Composition
Body Composition—Activity 1
Name ________________________________________________ Date _________________ Class Period ___________
Evaluation
1.What is body composition?
___________________________________________________________________________________
___________________________________________________________________________________
2.Why could a BMI measurement be an inaccurate depiction of a
person’s health?
___________________________________________________________________________________
___________________________________________________________________________________
3.What are three reasons why your body needs some fat?
___________________________________________________________________________________
Copyright © by The McGraw-Hill Companies, Inc. All rights reserved.
___________________________________________________________________________________
Fitness Zone Online Body Composition