W2- Body Composition Flashcards
What is body composition?
“Body’s relative amounts of FAT MASS and FAT-FREE MASS
Why is knowledge of body composition important? (3)
- Health and disease
- Performance
- Longevity
- What is percentage of essential fat is normal for both males and females?
- Dropping below what % has no benefit?
- Males = 3-5% (below 8% has no benefit)
- Females = 8-12% (below 14% has no benefit)
How is body composition affected by age? (2)
- Body composition tends to degrade with age.
- Lean body weight decreases and fat increases.
List of Caloric Input and Output.
Input
- Food
- Drink
Output
- Basal metabolic rate
- Dietary induced thermogenesis
- Physical activity
- Thermogenic effects of drugs
- Climate
- What is basal metabolic rate?
- What is dietary induced thermogenesis?
- Basal metabolic rate = How much kcal burnt to stay alive.
- Dietary induced thermogenesis = How much burnt to process intake
If someone gains too much fat tissue and each fat cells size is maximized the individual will undergo __________, what is this?
Hyperplasia = Increase in fat cells.
At what (3) points in life does hyperplasia normally occur?
- Last trimester prior to birth
- First year of life
- During adolescence
When people lose weight are they reducing the number of fat cells or shrinking them? What can this cause?
Shrinking the fat cells, which the body may interpret as early starvation which slows metabolism.
What is the Set Point Theory?
Body has a “comfortable” body composition.
What are the (3) body classifications? Explain each.
- Ectomorph = Long and lean.
- Endomorph = Rounded with lots of muscle and body fat, stocky structure.
- Mesomorph = Naturally high muscle-to-fat ratio.
Is an android or gynoid body type at increased risk for CVD? How does each look?
- Android = Apple body shape (increased risk for CVD).
- Gynoid = Pear body shape.
What is the best measure for CVD risk?
Waist circumference
> ___% of adults and adolescents do not get the recommended weekly physical activity level.
80%
Overnutrition Health Risks. (10)
- Heart disease and stroke
- High blood pressure
- High Cholesterol
- Diabetes
- Some cancers
- Gallbladder disease and gallstones
- Osteoarthritis
- Gout
- Breathing problems
- Early death
Undernutrition Health Risks. (8)
- Malnutrition
- Vitamin deficiencies
- Anemia
- Osteoporosis
- Decreased immune function
- Increased risk for complications from surgery
- Fertility issues
- Growth and developmental issues
What are some ways to assess body composition? (8)
- Underwater Densitometry
- Air Densitometry
- Dual-energy X-ray absorptiometry (DEXA)
- Bioelectrical Impedance Assessment (BIA)
- MRI and/or CT
- Fatfold/skinfold Technique
- BMI
- Waist Circumference
What are the advantages and disadvantages of Underwater Densitometry?
Advantages:
-Proven to be valid and reliable.
Disadvantages:
- Requires a lot of equipment/space.
- Equipment is expensive.
- Requires high skill level to administer and compute.
- Time consuming and involved.
- Not everyone can tolerate being submerged.
What are the advantages and disadvantages of Air Densitometry?
Advantages:
- Strong validity and reliability.
- Measurement time is short.
- Well suited for special populations.
Disadvantages:
- Very expensive.
- Not everyone can tolerate due to claustraphobia.
What are the advantages and disadvantages of DEXA?
Advantages:
- Quick and comfortable.
- Do not have to wear bathing suit.
- Excellent precision.
- Excellent validity and reliability.
Disadvantages:
- Costly.
- Radiation exposure.
- Validity reduced in very lean and highly obese patients.
- Requires certification.
What are the advantages and disadvantages of Bioelectrical Impedance Assessment (BIA)?
Advantages:
- Safe.
- Observer independent.
- Inexpensive.
Disadvantages:
- Unreliable.
- Hydration status alters results.
- Affected by many factors.
What are the advantages and disadvantages of MRI/CT?
Advantages:
- Highly specific as to tissue composition.
- Able to separate into regions.
- Highly valid and reliable.
Disadvantages:
- Costly.
- Time consuming.
- Radiation exposure with CT.
- Difficulty comparing results.
What are the advantages and disadvantages of Skinfold Technique?
Advantages:
- Quick and easy to perform.
- Noninvasive.
- Inexpensive.
- Can be performed nearly anywhere.
- Valid with proper technique.
Disadvantages:
- Technical sources of error.
- Mostly measures subcutaneous fat.
- Not as accurate with highly obese and very lean populations.
What are the advantages and disadvantages of Body Mass Index (BMI)?
Advantages:
- Quick and easy.
- Minimal equipment.
- Moderate validity.
Disadvantages:
- Does not consider fat free mass vs fat mass.
- Can improperly categorize participant’s weight category.
What are the advantages and disadvantages of Waist Circumference?
Advantages:
- Cheap.
- Minimal equipment and training.
- Moderate validity.
Disadvantages:
- Overestimates body fat on muscular patients.
- Underestimates body fat on lean participants.
-Underweight = BMI ___.
- Underweight = <18.5
- Normal = 18.5-24.9
- Overweight = 25-29.9
- Obese = >30
What is a high risk waist circumference for males and females?
- Males = >40in
- Females = >35in
What is a high risk waist to hip ratio for males and females?
- Males = >0.9
- Females = >0.85
