8. Body composition

Question 1

What is the body composition?

Answer 1

It’s the in vivo quantification of body components, the quantitative relationships between components and component alterations

Question 2

Body composition Methods

Answer 2

Model assumption
measurment errors
validation in study population
In vivo/in vitro methodologies
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Question 3

How the body mass can be divided (5 levels)?

Answer 3

Atomic (O+N+H+C…)
molecular (lipids, water, proteins…)
cellular (cell mass…)
tissues-system(adipose tissues, skeletal muscle + blood…)
wholebody (head+neck+ trunk+ lower upeer extremities)

Question 4

What are the BC methods according to BC levels?

Answer 4

1: neutronactivation
2: in vivo neutron activation analysis + water dilution
3: TBK + DXA (Dual-energy X-ray absorptiometry)+ bromide dilutions
4: CT/DXA + blood dilution
5: general status

Question 5

wHAT IS THE ANTHROPOMETRY?

Answer 5

the scientific study of the measurements and proportions of the human body.
Arm cirumference and triceps skinfold thickness

Question 6

Densitometry?

Answer 6

estimation of body composition by knowing the body density

quello che assomiglia ad un uovo

Question 7

How is the total body water calculated?

Answer 7

By deuterium dilution, tritium dilution, labled oxygen dilutions, bioelectric impedance

Question 8

How is the total boby cells calculated?

Answer 8

Measurment of naturally occuring 40K in a body counter
estimates body cell mass via intracellular K

BMC= 0.0833 *TBK(total body potassium)

Question 9

Whats the bioelectrical impedance analysis?

Answer 9

BIA[1] actually determines the electrical impedance, or opposition to the flow of an electric current through body tissues which can then be used to estimate total body water (TBW), which can be used to estimate fat-free body mass and, by difference with body weight, body fat.

A fat salami have a high resistance compared to a lean salami
resistance is proportional to fat

Question 10

What are the different methods in the Bioimpedance?

Answer 10

Single frequency BIA
multifrequency BIA
Bioelectrical spectroscopy (low frequency current does not go inside cells, with high current yes)

Question 11

What affect BIA?

Answer 11

body position
hydratation status
consumption of food and beverages 
air and skin T
physical activity
conductance ox the table

Question 12

What are the conclusion about BIA?

Answer 12

BIA convenient, portable, ok in helaty subjects but less in the one with disturbed water,electrolyte balance
not valid in extreme BMI body mass index

Question 13

What is DXA? what does it measure?

Answer 13

Dual energy X-ray absorptiometry

bone mineral 
fat
fatfree tissues
skeletal muscle mass
fat localization ratio
CV

Question 14

How do you measure muscle mass?

Answer 14

CT/MRI (Computed Tomography) scan and an MRI (Magnetic Resonance Imaging)
DXA
bioimpedance
anthropometru

Question 15

How do you calculate the body mass index?

Answer 15

BW body weight
BH body height
BMI: BW/BH^2

Question 16

Tell about the BMI classifications

Answer 16

<18.4 malnutrition
18.5-24.9 normal
25-29 overweight
30-39 obese ( you can calculate obesity also by circumferences)

Question 17

which are the trends in sweden for obesity?

Answer 17

50% are overweihht or obese
increase up to 14%
most take place in the middle afe
women increase from 45 to 53 man from 65 to 70%

Question 18

Facts bout obesity

Answer 18

decrease by level of education
adults without a high school degree are more obese and this decrease with the type of qualification

It can lead to CVD diabetes, no glucose tolerance, low level of HDL
sleep apnea
probelm in gastrointestinal tract
artritis 
mestrual disfunction
infertility
kidney stones
cancer
mental dysfuncions

Question 19

How to treat obesity?

Answer 19

decrease energy intake
(beheviour, low carb, anorectic drugs, surgery (gastroplastic, gastric by pass) )

Increase energy expenditure
increase fecal energy losses