Lab 3: Body Composition Flashcards
Essential Adipose tissue
-Necessary to sustain life
-Found in marrow, organs, and CNS
-Females need more
Non-Essential adipose tissue
-Storage fat: Energy
-Found in intramuscular, intermuscular, visceral, and subcutaneous depots
Non-Essential Fat Depots
-Intramuscular: In muscle fibers
-Intermuscular: Between muscles
-Visceral/Central/Abdominal: Surrounds organs
-Subcutaneous: Beneath the skin
Ways to assess obesity/fat tissue
-Direct: Cadavers
-Indirect: Estimates
Co-morbidities of obesity
-Type 2 diabetes
-Cardiovascular Disease
-Depression
-High Cholesterol
-Cancer
-Hypertension
-Stroke
Adult Overweight & Obesity in the US
-35% of adults overweight
-32% of adults obese
-9% are severely obese
-Obesity has DOUBLEd in the past 30 years
Children & Adolescent Overweight & Obesity in the US
-13% of 2-5 year-olds are obese
-20% of 6-11 year-olds are obese
-21% of 12-19 year olds are obese
-Obesity has TRIPLED in past 30 years
BMI Classification
-Underweight: <18.5
-Normal: 18.5-24.9
-Overweight: 25-29.9
-Obesity: 30+
Stages of obesity by BMI classification
-Stage 1: 30.0-34.9
-Stage 2: 35.0-39.9
-Stage 3: >40
BMI Measurment
(Weight(kg))/(Height(m^2))=BMI
Body fat percentage from BMI
BF%: (1.20BMI) + (0.23age) - (10.8*sex)
-Male=1
-Female=0
Waist circumference ratio
Compares ratio between waist and hip circumferences to give insight on fat distribution
Ratio = (waist circumference/hip circumference)
Measuring circumferences
-Waist: Horizontal measure taken at narrowest part of torso
-Hip: Horizontal measure taken at widest part of hip
Bioelectrical Impedance
Based on principle of electrical current flowing through body at certain speed depending on body composition. Water in muscle conduces electricity well while fat resists.
-Faster current: Lower BF%
-Slower current: Higher BF%
Bioelectrical impedance pros
-Quick and easy to use
-Beneficial for large sample sizes
-Considers height, age, weight, and sex
Bioelectrical impedance cons
-Assume constant hydration factor
-Inaccurate for extremely under or overweight individuals
-Estimates lower body comp from upper body
Skinfolds
Measures subcutaneous fat
-Based off assumption that 1/3 of total body fat is subcutaneous
Jackson-Pollock Method
Based on approximation that subcutaneous fat is a proportion of total fat in the body
3-Site fold for men
Chest, abdomen, and thigh
3-Site skinfold for women
Triceps, suprailiac, thigh
Normal body fat ranges for men
-ADA: 13-18% (As low as 5-12%)
-ACE: 14-24% (As low as 6-13%)
-ACSM: 10-22%
Normal body fat ranges for women
-ADA: 21-25% (As low as 10-20%)
-ACE: 21-31% (As low as 14-20%)
-ACSM: 20-32%
Densitometry
Application of body density to derive body composition
-Density = (Mass/Volume)
Two compartment model of body composition
-Fat free mass density = 1.1g/mL
-Fat mass density= 0.9 g/mL
BOD POD
-Interior volume and volume with subject are measured to find subject volume
Pros of BOD POD
-Subject and user friendly
-Ideal for special populations (Kids & Elderly)
-Excellent validity (+/- 0.3%)
-Fast (5 minutes)
Cons of BOD POD
-Expensive
-Also assumes constant density of FFM and fat for prediction of % Body fat from total body density
Hydrodensity
Uses archimedes principle that uses loss of water to equal loss of weight in water
Hydrodensity advantages
-Very accurate
-Gold standard
Disadvantages of hydrodensity
-Very subject dependent
-Timely and costly
-High skill needed from technician
-Assumes constant density of FFM and fat for prediction of BF%
