Dear Colleagues. This topic is concerning to understand methods of evaluation of body composition and their applications in medical practice; as obesity is the most important concerns of morbidity and life expectancy, healthcare system have to understand its importance for evaluation. Best regards Dr Majid Abi Saab

1. Body Composition
Concept and Utility
By
Dr. Majid Abi Saab
Consultant Rheumatologist
Al Ahli Hospital
QA

2. Bo dy Co m po sitio n
Most methods consider body having two components:
• fat component, i.e. fat mass
• fat-free component, i.e. fat-free mass (FFM)
Body fat %
• average values: women, ~25%; men ~15%
• minimal values: women, 8-12%; men – 5%
• considered obese: women, >30%; men >20%
e sse ntialand no n-e sse ntialfat

3. Reference body composition for man

4. Reference body composition for women

5. Rating s o f % Fat (ag e s 20 -29 yr)
Rating Men Women
Excellent 6-9 10-17
Good 10-14 17-21
Acceptable 15-19 21-25
Too Fat 20-22 27-32
Obese >22 >32

6. De te rm ining Ide alBo dy We ig ht
Indire ct appro ache s
Me tro po litan he ig ht– we ig ht table s
body mass index (BMI)
• weight (kg) / height2
(m2
)
• ideal range is 18-25
• >30 considered obese
Dire ct appro ache s
• hydrostatic (underwater) weighing
• anthropometric (skin-fold) measurements
• bioelectrical impedance analysis (BIA)
• air-displacement plethysmography (BOD POD volume)
• DEXA The Most Accurate

7. X Y
x y

8. Bio e le ctricalIm pe dance

9. GE Lunar DEXA Body composition
FDAapprovedtheLUNARDEXAforBodyComposition
Indications foruse: The GE LunarBody Composition
“…management of diseases/conditions where the disease/condition itself, or it's
treatment, can affect the relative amounts of patient fat and lean tissue. “
Main indications: Obesity | Metabolic Syndrome | Chronic Steroids treatment | Back
pain related android obesity.
“Some of other diseases/conditions for which body composition values are useful
include chronic renal failure, anorexia nervosa, AIDS/HIV and cystic fibrosis.

10. X-ray Source
X ray Absorption
Bone has a Higher
XRay Attenuation than
Soft Tissue

11. DEXA Physics
Xray attenuation is depending on the amount, type of tissue and energy level
Bone
Soft Tissue
Low Energy High Energy keV
Abs(HE keV) = Abs(HE keV) ST + Abs(HE keV) B
Abs(LE keV) = Abs(LE keV) sT + Abs(LE keV) B
Abs(HE keV) = Abs(HE keV) ST + Abs(HE keV) B
I(HE keV) = Io exp(µHE.ST DST + µHE.B DB)
Abs(LE keV) = Abs(LE keV) ST + Abs(LE keV) B
I(38keV) = Io exp(µLE.ST DST + µLE.B DB)
Ab
s
DST ; DB could be calculated
and so MB =DB x AreaB
MST = DST x AreaST

12. Measure Bone/Fat/Lean Using DXA
-3Compartment model
 Define anatomical region
 Define bone area (green pixel)
 Calculate Bone mass using two energies
 Outside of bone region, R-value -> %Fat using two
energies
 Use local uniform composition over Bone region to
calculate total soft tissue and after fat - lean in each
sub-regions
 Calculate Total weight by summing up Fat, Lean
and Bone masses for all sub-regions

13. Obesity
Female (42years) (Height: 162 cm / Tissue (kg) (Fat + Lean): 96,2 to
93kg)
A/G decrease : DECREASE fat in android!
Fat (kg): 49,9 to 44,6 to 45,7 / Lean (kg): 46,2 to 47,4 to 47,3kg

14. Normal Weight Obese Syndrome
Female (26 years) (Height: 158 cm / Total Mass (kg) : 54,8 to 52,3kg)
Follow up case over1,5 year
BMI from22,2 to 21,2 (normal)

15. Normal Weight Obese Syndrome
Female (26 / H:158 cm / W:54,8 to 52,3kg) Tissue (kg) (FM + LM): 52,7kg to 50,2kg
What did she lose over1,5 year, Fat and/orLean?
Fat (kg): 18,9 to 16,5 / Lean (kg): 33,7kg to 33,7kg

18. Ask yourself
• Are you Obese?
• Do you suffer from Obesity related disorders?
• Metabolic?
• Chronic Back Pain, Knee/Hip OA?
• Do you have difficulties on making regular/sport activities?
• Is your HAQ within normal?

19. We ig ht Manag e m e nt
• diet modification
• physical activity modification
• behavior modification
Principles Common to Successful Programs

20. Weight Management
base d o n Ene rg y Expe nditure (kcal/m in)
Activity 56 kg 83 kg
basketball 7.3 11.5
Circuit training 9.8 15.4
Cycling (9.4 mph) 5.6 8.3
Running (9 min/mile) 10.8 16.0
Running (7 min/mile) 13.3 18.5
Swimming (slow) 7.2 10.6
Swimming (fast) 8.7 12.9
Tennis (singles) 6.1 9.0
Walking (3.0 mph) 4.5 6.6
Sitting (quietly) 1.2 1.7

21. We ig ht Manag e m e nt
base d o n Intake
Weight change = Calories (energy) intake – energy
expenditure
Ene rg y Intake
caloric density
• CHO = 4 kcal/g
• protein = 4 kcal/g
• fat = 9 kcal/g
• ethanol = 7 kcal/g
influence of diet composition

22. Effe cts o f lo w-
e ne rg y intake o n
RMR
Bray, Lancet, 1969

23. Yo ur are o ffe re d a tiny part o f Snicke r’s candy
bar.
It co ntains 6 g o f fat and the re is 1 0 0 kcalo f
e ne rg y.
What is the pe rce ntag e o f e ne rg y that co m e s
fro m fat?
a. 6 kcal
b. 600 kcal
c. 6%
d. 54%
e. 60%
f. cannot be determined

24. Weight Management
Calculate % Intake fro m Fat
Breakfast - McDonald's
Total Energy
(kcal)
Fat
(g)
Sausage McMuffin w/Egg 517 33
1% Milk - 8 oz 110 2
Hash Brown Potatoes 125 7
Lunch - Burger King
Bacon Double Cheeseburger 510 31
French Fries - regular 227 13
Chocolate Shake - 10 oz 374 11
Snack
Snicker's Candy Bar 280 13
Dinner - Taco Bell
Two Tacos 372 16
Combination Burrito 404 16
Pepsi - 24 oz 288 0
TOTAL (40% of intake from fat) 3,207 142

25. Weight Management
Be havio r Mo dificatio n
• avoid automatic eating
• plan meals ahead of time
• don’t serve self more food than should eat
• avoid social binges
• practice other stress management techniques
• set realistic goals
• incorporate physical activity into program

26. Thank you for sharing