This document discusses bioelectrical impedance analysis (BIA) for measuring body composition. It begins by explaining what BIA is and how the measurements can depend on factors like ethnicity, age, and genetics. It then covers the positive aspects of BIA, such as being easy to use and inexpensive, as well as negative aspects like a lack of standardization. The document goes on to describe the mechanisms of BIA, including how electric currents are passed through the body to determine total body water, extracellular water, and fat-free mass. It also discusses single and multi-frequency BIA methods and ideal measurement conditions. In the end, it notes there are obstacles to relying solely on BIA and that an expert's experience

1. BIA TEST PAPER LIKE YOU HAVE
NEVER SEEN IT BEFORE
RD AHMAD ZYOUD
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2. WHTS THE BIA
Method to determination of the fat-free mass
(FFM) and total body fat in subjects when using
appropriate population, age or pathology-
specific BIA equations and established
procedures
BIA results depends of ethnicity, age, gender,
hormonal and genetic variations
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3. Positive points
• Easy to use
• It doesn't take long to get results
• cheap cost
• It gives accurate results for healthy people
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4. Negative points
• lack of standardized method
• quality control procedures
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5. Mechanism of Action
• The device passes an electric current at
certain frequencies and based on the
resistance of the body fluids to this current, it
determines the mass of “TBW” and “ECW” as
well as the BONE MINERAL CAOUNT and thus
we have a full body weight without fat and it
is called FAT FREE MASS
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6. Mechanism of Action
• We have equations and specific algorithms in
order for the device to analyze the resistances,
and here lies the negatives of the analysis
• As the equations used differ according to
people and their physical structures, which
leads to the lack of standardization of the
devices and also their inability to keep pace
with these changes.
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7. Mechanism of Action
• The device deals with the human body as if it
were cylindrical, as it calculates the amount of
electrolytes that the current crosses from the
length of the human body, which is from the wrist
to the ankle, and through a specific logarithms
that compares them and calculates the amount
of fluids, taking into account that approximately
75% of the human body water
• errors occur when there are alterations in
resistivity of the conductive material
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8. Mechanism of Action
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9. Methods of bioelectrical impedance
analysis
• We have tow type of BIA
1. Single frequency BIA (SF-BIA)
2. Multi-frequency BIA (MF-BIA)
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10. Methods of bioelectrical impedance
analysis
• Single frequency BIA (SF-BIA)
SF-BIA, generally at 50 kHz, is passed between surface
electrodes placed on hand and foot
not measuring TBW but a weighted sum of extra-
cellular water (ECW) and intra-cellular water (ICW)
SF-BIA permits to estimate fat-free mass (FFM) and
TBW, but cannot determine differences in ICW.
BIAresults are based on a mixture theories
SF-BIA is not valid under conditions of significantly
altered hydration this does not negate its use to predict
absolute FFM or TBW in normally hydrated subjects
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11. Methods of bioelectrical impedance
analysis
• Multi-frequency BIA (MF-BIA) As with SF-BIA,
MF-BIA uses empirical linear regression
models but includes impedances atmultiple
frequencies. MF-BIA uses different
frequencies (0, 1, 5, 50, 100, 200 to 500 kHz)
to evaluate FFM, TBW, ICW and ECW
• At frequencies below 5 kHz, and above 200
kHz, poor reproducibility have been noted
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12. Methods of bioelectrical impedance
analysis
• MFBIA was more accurate and less biased
than SF-BIA for the prediction of ECW
• SF-BIA, compared to MF-BIA, was more
accurate and less biased for TBW in critically ill
subjects
• MFBIA was unable to detect changes in the
distribution or movement of fluid between
extracellular and intracellular spaces in elderly
patients
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13. Measurement conditions
• To reach the best results, we have to take
some procedures to adjust the measurement
accuracy to the highest limit, so here is the
following set of procedures before the
examination
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14. Measurement conditions
• Do not make in any kind of physical or sports
activities within 24 hours before the
measurement date
• Wear the least weight you have
• You must fast 4 hours before the
measurement
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15. Measurement conditions
• Drink two glasses of water before the
measurement time
• Go to the bathroom half an hour before the
measurement time
• The room temperature in which it is measured
should be 20 Celsius
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16. Measurement conditions
very important
• The measurement is always on the same
device and same time of the day if you want
to monitor weight and fat mass
• More electrodes, more accuracy
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17. Measurement results
• Protein and fat Non-conductive
• Tbw and Ecw : Total fluid mass extracellular fluid
mass and bone minerals( Ca//P ) is the first thing
measured by device then TBW and ECW used by
equations are used to determine the amount of
protein and body cell mass
• Protein : It is considered an indicator of active
cells because cells membrane contain of protein
and ICW / ECW , and therefore, through
equations, it is possible to calculate muscle mass
and active cells
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18. Measurement results
• bone minerals (through which bone density
and weight can be detected) its increase when
body weight increase to improve the skeletal
ability to carry additional weight and reduce
the chance of fragility or fractures
• TBW+protein = soft lean mass “SLM”
• TBW+Protein+bone mineral = fat free mass
• Fat free mass “FFE”-Total body weight= body
fat
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19. Measurement results
• ECW:TBW its indicator for malnutrition and water retention and
inflammation etc.
• Body cell mass calculated as 70-75% of SLM and it can help to determine
basal metabolic rate “BMR”
• Skeletal muscle mass “SMM” calculated as 60% of SLM
-note that when your body weight increase the body water will be
increase to improve ability to carry additional weight by the muscle this
led to increase SMM because it’s a percentage from SLM
• Segmental fat mass reading by Segmental of fat free mass in every part of
the body
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20. Measurement results
• Abdominal circumference calculated by fat
free mass in trunk and body fat at the same
time
every 1kg of fat give 1-1.2cm according to age
sex and race
male less than 102cm
female less than 88cm
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21. Measurement results
• VFL : its calculated by Abdominal
circumference and BMI and cross sectional
reading of frequency
0-8 level normal
9-11 boundary
12-15 visceral obesity class 1
16-20 visceral obesity class 2
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22. Measurement results
• Obesity dagree : ((currant weight - stander
weights)/ stander weights) * 100%
very week less than -20%
week -20% to -10%
normal -10% to +10%
little obese +10% to +20%
obesity more than 20%
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23. In the end, there are many obstacles to relying
on BIA for the components of the body, and the
experience and practice of the specialist remains
the decisive factor in determining the correct
measurements.
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24. With Regards
RD. Ahmad Zyoud
THE END
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