EXSC 191 Exam 2 Notes.docx - Chapter 18: Body Composition...

Chapter 18: Body Composition
Body Composition
- Refers to the relative amount of fat and fat-free tissues in the body
- Fat and nonfat components of human body
o Percent body fat (adipose tissue): proportional amount of fat in the body based
on total weight
o Lean body mass: body weight without body fat
Types and Functions of Fat
- Essential fat:
o Located in nerves, heart, glands, and liver
o Necessary for normal physiological function
o 3% for men
o 12% for women
- Storage fat:
o Visceral (around organs) or subcutaneous (below the skin)
o Functions include:
 Insulator
 Energy substrate
 Padding against physical trauma
 8-22% for me
 20-35% for women
Regional Fat Deposition: Visceral Fat
- Visceral body fat poses greater health risks because it is more active and has greater
access to the circulation
- Increase risk to CVD and type 2 diabetes
How is Body Composition Related to Health?
- Android pattern of obesity
o Fat is stored in upper body and around the waist
o Most common in men
o Apple shape= higher health risk
- Gynoid pattern of obesity
o Fat is stores in waist, hips, and thighs
o Most common in women
o Pear shape= lower health risk
Waist-to-Hip Ration (pear vs. apple)
- Abdominal obesity increases risk of:
o Heart disease
o High blood pressure

o Cholesterol
o Diabetes
o Cancers
o Early death
Chronic Conditions of Overweight and Obesity
- Cardiovascular disease
- Diabetes
- Cancers (breast, prostate, colon)
- Joint problems and osteoarthritis
- Sleep apnea
- Gallbladder disease
- Menstrual abnormalities
- Difficulty with conception and pregnancy
Health Effects of Underweight
- Loss of muscle mass and strength
- Osteoporosis
- Menstrual abnormalities that can lead to infertility
- Sever underweight conditions may lead to:
o Heart problems
o Digestive disorders
o Kidney damage
o Anemia
o Lethargy
o Muscle weakness
o Dry skin
o Compromised immune function
Use of Body Composition Results
- Serves as a baseline data for repeated testing
- Provide motivation for goal setting
- Provide awareness about health risks
Methods used to Assess Body Composition
- Anthropometry
o BMI: ratio of a person’s weight to height squared (kg/m^2)
 1 kg = 2.2 lbs
 1 in: 2.54 cm
 Ex: 170 lbs / 2.2 = 77.27 kg
 6 foot = 72 in
 72 in x 2.54 = 182.88 cm
 182.88 / 100 = 1.8288 m

 (1.8288 m)^2 = 3.3445 m^2
 BMI= 77.27 kg / 3.3445 m^2 = 23.1
o Circumference
o Waist to hip ration
- Skinfold technique
- DEXA
- Underwater weighing
- Bod Pod
- Bioelectrical Impedance Analysis (BIA)
BMI Classifications
BMI Classification
< 18.5 Underweight
18.5 – 24.99 Acceptable
25 – 29.99 Overweight
30 – 39.99 Obese
>/= Sever Obesity
Body Mass Index
- Good estimate of body composition at population level but not at individual level
- Does not take muscle mass into account
- Does not equal to percentage of body fat
Waist Circumference
- Waist girth measurement
- Inches at the smallest point
Men Women Disease Risk for CVD
< 35.5 < 32.5 Low
35.5-40 32.5-35 Moderate
>40 >35 High
Waist to Hip Ratio
- Waist (inches) at smallest point/ Hips (inches) at largest point
- Men - Women - Disease Risk
- </= .95 - </= .80 - Very low
- 0.96-0.99 - 0.81-0.84 - Low
- >/= 1 - >/= .85 - high
Skinfold Technique
- measures thickness of skin at specific body sites to estimate toal body fat
- 7 sites:
o Chest
o Axilla

o Triceps