1. Body composition and Practical Nutritional Assessment
Khursheed Jeejeebhoy

2. Determinants of Nutritional Status
Nutritional health
a state of equilibrium
nutrient intake and requirements balance.
Malnutrition
net nutrient intakes < requirements.
change in body and blood composition
changes in body and blood composition have traditionally used to assess nutritional status.

3. Nutritional Assessment: Veterinary approach
C– P--

4. Objective of Nutritional Assessment
Veterinary Objective:
Mass of muscle, fat and viscera in the carcass.
Clinical Objective:
To improve patient outcome.
Can measurement of muscle, fat and viscera predict outcome?

5. Levels of Body Components
Tissue-Organs
Cellular
Molecular
Atomic
Adipose tissue
Adipocyte
Lipid
Hydrogen
Water
Skeletal Muscle
Cells
Carbon
Visceral Organs
Oxygen
ECF
Protein
Skeleton
ECS
Mineral
N, Ca,P,K,Na,Cl

6. Nutritional Assessment: Tissue-Organs
Body Weight and Weight Loss
BMI = Wt/Ht2 < 15 is associated with mortality
Unintentional weight loss is associated with mortality
Weight is difficult to assess due to:
Dehydration
Edema
Dialysate
Weight loss estimate has errors of recall

7. Nutritional Assessment: Tissue-Organs
1. How much muscle and fat: Anthropometry
Arm muscle circumference
Skin Fold thickness
2. How much circulating protein: Visceral Protein
Albumin
Prealbumin
Transferrin
3. Errors of Antropometry
Errors due to Baseline values
Variability of measurement
What is abnormal?
Errors due to edema
4. Errors of Visceral Protein
Altered by hydration status
Altered by Protein loss (GI and renal)
Altered by Infection

8. Nutritional Assessment: Tissue-Organs DUAL-ENERGY XRAY ABSORPTIOMETRY (DEXA)
Two low level energy xrays to differentiate tissues of different densities.
The only method for assessing the skeleton.
Differentiates body composition into:
Fat
Muscle
Bone
No data to predict outcome

9. Levels of Body Components
Tissue-Organs
Cellular
Molecular
Atomic
Adipose tissue
Adipocyte
Lipid
Hydrogen
Water
Skeletal Muscle
Cells
Carbon
Visceral Organs
Oxygen
ECF
Protein
Skeleton
ECS
Mineral
N, Ca,P,K,Na,Cl

10. Nutritional Assessment: Cellular
Cell mass = Total body potassium / 150 X 1/80
Potassium content of cells = 150 mmol/L
Solid to fluid in cells = 1:4
Intracellular potassium is very sensitive to malnutrition and refeeding

11. Nutritional Assessment: Cellular Am J Clin Nutr 1982;35(suppl) 1117-1127
Patients with anorexia Nervosa
Weeks of feeding TBN TBK K/TBN
kg mM

12. Levels of Body Components
Tissue-Organs
Cellular
Molecular
Atomic
Adipose tissue
Adipocyte
Lipid
Hydrogen
Water
Skeletal Muscle
Cells
Carbon
Visceral Organs
Oxygen
ECF
Protein
Skeleton
ECS
Mineral
N, Ca,P,K,Na,Cl

13. Nutritional Assessment: Molecular
Body Weight = Fat mass (FM) + Fat Free Mass (FFM)
Hydration of FFM = 73%
FFM= Total Body Water/0.73
Total Body Water can be assessed by:
Isotope dilution
Bioelectric Impedance

14. Nutritional Assessment: Molecular
Isotope dilution
Total body water
Extracellular water
No correlation with outcome
Bioimpedance Analysis
Easy to perform
Measures body water
DEXA
Measures FM
Muscle mass from which FFM can be derived
Bone mass

15. Levels of Body Components
Tissue-Organs
Cellular
Molecular
Atomic
Adipose tissue
Adipocyte
Lipid
Hydrogen
Water
Skeletal Muscle
Cells
Carbon
Visceral Organs
Oxygen
ECF
Protein
Skeleton
ECS
Mineral
N and Ca

16. Nutritional Assessment: Atomic
Measured By:
Hydrogen Neutron Activation
Carbon Inelastic Neutron scattering
Nitrogen Prompt Gamma Emission
Calcium Neutron Activation

19. Subjective Global Assessment

39. Predictive value of a test

40. Predictive ability of SGA

41. SGA assessment and record of other risk factors influencing prognosis
Nutritional Prognosis in Hospital Patients Perman et al. Am J Clin Nutr 2002;75:426S
448 Hospital Patients
SGA assessment and record of other risk factors influencing prognosis
Logistic regression to evaluate independent risk of malnutriton by SGA on complications and mortality

42. Nutritional Prognosis in Hospital Patients Perman et al
Nutritional Prognosis in Hospital Patients Perman et al. Am J Clin Nutr 2002;75:426S
* only odds ratio of BC not different from A *

47. Mohandas IJG 2005;24:

48. Subjective Global Assessment and Cancer
Thoresen et al. Palliat Med ;16:33-42.
Sensitivity 96% and specificity 83%
Persson et al. Clin Nutr 1999; 18:71-77
Survival Lower in SGA B+C vs A (P<0.001)