Exam (elaborations)
Body Composition – Questions With Complete Solutions
- Course
- Institution
Body Composition – Questions With Complete Solutions
[Show more]
Seller
Follow
Studycafe
Reviews received
Content preview
Body Composition – Questions With CompleteSolutions
Components of total body mas ✔️Ans - 1. Adipose
2. Lean body mass (muscle, bone, extra-cellular, water, other)
Measures of absolute body components (to separate adipose from lean
body mass) ✔️Ans - 1. Dilution
2. Densitometry
3. Impendence
4. Anthropometric measures (skinfolds, circumference measures, height
and weight)
Principle of dilution ✔️Ans - Calculate total body water to derive lean
body mass
Assumption of dilution ✔️Ans - Water makes up 73% of lean body mass
and no water in adipose
Dilution procedure ✔️Ans - 1. Consume known amount of substance
(radioactive)
2. Wait for mixing
3. Measure concentration of substance in urine
4. Lean body mass = (total body water/0.732)
Disadvantage of dilution ✔️Ans - Requires drinking radioactive
substance and measuring urine: not feasible for large studies
Densitometry ✔️Ans - Underwater weighing
Principle of densitometry ✔️Ans - Body composition estimated using
body density (density=mass/volume)
Assumption of densitometry ✔️Ans - Fat tissue is less dense than fat-free
tissue, uses standard equations to calculate % body fat assuming constant
density for lean body mass
2 compartment model of densitometry ✔️Ans - fat and fat-free mass
, Which method is considered the gold standard for % body fat? ✔️Ans -
Densitometry (underwater weighing)
How Densitometry works ✔️Ans - 1. Measure body weight in air and in
water and calculate the difference (loss of weight in water = the weight of
the volume of water displaced)
2. Use known density of water to calculate the volume of water displaced
(=volume of the body)
3. Based on the volume and weight of the body, you can calculate its density
4. Standard formula: density=body fat%
Densitometry using 'BOD POD' ✔️Ans - Use of air pressure instead of
underwater weighing to calculate body volume. Uses Boyle's law: pressure
and volume vary inversely with one another. Therefore, monitoring
pressure changes in a closed chamber allows one to calculate volume.
Limitations of densitometry ✔️Ans - 1. 2-compartmental model:
assumes that the components that make up the fat-free mass (water,
minerals, protein) are relatively constant from person to person)
2. Labor intensive
3. No information on fat distribution
Principle behind impedance and conductance to measure adiposity ✔️Ans
- Lean body mass conducts electricity better than fat
What is conductance? ✔️Ans - Pass body through a large coil and
measure difference between impedance when coil empty vs. when subject
present
Limitations to conductance? ✔️Ans - 1. Expensive
2. Not portable
3. Not practical for large studies
What is impedance (BIA- bioelectrical impedance analysis) ✔️Ans - Pass
low-level electrical signals using electrodes placed on subject. The faster
the signal travels, the more lean mass.
Advantages to impedance ✔️Ans - 1. Inexpensive
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Studycafe. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $9.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
78252 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now