2. Learning Objectives
To the principles of measurement of
energy expenditure
To now how to diagnose a risk of
malnutrition
To know the methods for measurement
of body composition
To be able to estimate energy intake in
hospitalized patients
3. Flow of energy in biosphere
H2O + CO2
+N
O2 O2
ATP
ph CHO
ot
os Fat
yn
H2O + CO2 th Proteins
es
is
N
4. Energy expenditure
FOOD
O2
CHO CO2
Fat H 2O
Proteins Nitrogen
Heat
BODY
RESERVES
Total energy expenditure - TEE
resting energy expenditure - REE
diet induced energy expenditure - DEE
activity induced energy expenditure - AEE
5. Components of energy expenditure
-adult person-
Activity induced energy Is the most variable
expenditure ∼ 60-70% component of TEE
Dependent on physical
activity
An postprandial increase in
Diet induced energy EE above basal fasting level
expenditure ∼ 10% Lasts for several hours
after meal
Maintaining cell membrane
ion gradients
Constant protein synthesis
and breakdown
Resting energy expenditure
Amino acid metabolism
∼ 60-70%
Glycogen synthesis and
breakdown
Fatty acids cycle
Gluconeogenesis
Energy for breathing and
heart function
6. Energy expenditure measurement
Direct calorimetry
Measurement of heat produced during
energy processes
Indirect calorimetry
Measurement: O2 consumption
VO2 production
7. Direct calorimetry
Whole body heat production
Special chambers
difference in heat coming into and out of the
chamber
V
T1
V
T2
EE ∼ ∆Q = V (T2 – T1)
8. Indirect calorimetry
Measurement of O2 consumption
VO2
production
V
cO2, cCO2
V
cO2, cCO2
EE ∼ VO2 consumption and VCO2 production
9. Indirect calorimetry
flow CO2-analyser
respiratory air
ventilated hood
or gasmeter O 2-analyser
respiration
chamber
outdoor air ² CO 2 ²O2
outdoor air
Westerterp K, Schols A Basics in Clinical Nutrition, 2004
11. Indirect calorimetry
VO2 = 0.829 CHO + 2.02 Fat + 6.04 Nitrogen
VCO2 = 0.829 CHO + 1.43 Fat + 4.84 Nitrogen
Substrate oxidation:
CHO = 4.59 VCO2 – 3.25 VO2 – 3.68 Nitrogen
Fat = 1.69 VO2 – 1.69 VCO2 – 1.72 Nitrogen
Protein = 6.25 Nitrogen
Energy expenditure:
EE = 3.87 VO2 + 1.19 VCO2 – 5.99 N
12. Indirect calorimetry
Energy expenditure can be calculated both from VO2 and
VCO2:
Calculation from VO2 and VCO2:
EE = 3.95 VO2 + 1.11 VCO2
Calculation from VO2:
EE = VO2 (3.95 + 1.11 RQ) – moderately dependent on RQ
Calculation from VCO2:
EE = VCO2 (1.11 + 3.95/RQ) – Highly dependent on RQ
Doubly labeled water, labeled bicarbonate
13. Relationship between REE and RQ
[REE calculation based on VO2 or on VCO2]
120,0
115,0
Difference in REE [%]
110,0
105,0
VCO2
100,0
VO2
95,0 VO2 a VCO2
90,0
85,0
80,0
0,7 0,75 0,8 0,85 0,9 0,95 1
RQ
REE calculated from VCO2 is more dependent on RQ (possible
mistake 15%) then if calculated from VO2 (possible mistake
4%)
14. Measurement of EE using doubly labeled water
2H 18 O
2
2H 18 O
Labels Labels water and
water pool bicarbonate pools
2HHO H 2 18 O CO 18 O
K2 = rH K18 = r CO + rH
2O 2 2O
K18 - K2 = r CO
2
Principle of the doubly labelled water (2H218O) method for the measurement of
carbon dioxide production (rCO2) from the elimination rates of 18O (k18) and 2H
(k2). The elimination rate of 2H is a function of water loss (rH2O) while k18 is a
function of rCO2 and rH2O.
Westerterp K, Schols A Basics in Clinical Nutrition, 2004
15. Relationship between heart rate and energy
expenditure
12,00
10,00
8,00
Energy expenditure
[kcal/min.]
6,00
4,00
2,00
0,00
40 50 60 70 80 90 100 110 120 130 140
Heart rate [b/min]
16. Relationship between heart rate and energy
expenditure –whole group
14
12
10
Energy expenditure
8
[cal/min.]
6
4
2
0
75 95 115 135 155 175
Heart rate [b/min]
17. Relationship between heart rate and energy
expenditure –individual patients
18
16
14
12
Energy expenditure
[cal/min.]
10
8
6
4
2
0
95 105 115 125 135 145 155
Heart rate [b/min]
18. Harris-Benedict equations
The most common approach to predict resting energy expenditure
Male:
REE = 66.5 + (13.8 x weight) + (5.0 x height) - (6.8 x age)
Female:
REE = 655.1 + (9.6 x weight) + (1.8 x height) - (4.7 x age)
19. The theoretical reserves of a 74 kg
man
Body substrate Substrate weight Energy content
( kg ) ( kcal )
Fat 15 141.000
Protein 12 48.000
Glycogen (muscle) 0.5 2000
Glycogen (liver) 0.2 800
Total 191.800
20. Prevalence of undernutrition
• Ambulatory outpatients 1-15%
• Institutionalized patients 25-60%
• Hospitalized patients 35-65%
Omran et al, Nutrition 2000
• These rates depend on how malnutrition
is defined
22. ESPEN Guidelines
for Nutrition Screening
• All patients should be screened on admission to the
hospital
• If the patient is at risk, a nutrition plan is worked
out by the staff
• Monitoring and defining outcome has to be
organized
• Results of screening, assessment and nutrition care
plans should be communicated to healthcare
professionals to which the patient is transferred
• Outcome should be audited and communicated to
furnish the data on which future policy decisions
can be made
Nutrition Screening 2002, Clin Nutr 2003
www.espen.org → Education → Guidelines
23. Nutritional screening
Is a tool to rapidly and simply
evaluate whether the patient is
at risk to be or to become
malnourished
25. Screening tools
• Nutritional Risk Index1 - biochemical
• Subjective global assessment2
• Malnutrition Universal Screening
Tool (MUST)3
• Nutritional Risk Screening
(NRS 2002)4
• MNA (elderly)5
1 Veterans Affairs, New Engl J Med 1991 4 Kondrup et al, Clin Nutr 2003
2 Detsky et al, JPEN, 1984 5 Vellas et al, Nutrition 1999
3 BAPEN
26. Nutritional risk screening
Subjective global assessment (SGA)
I Patient‘s history
(weight loss, change in dietary intake, gi-symptoms,
functional capacity)
II Physical examination
(muscles, subcutaneous fat, edema, ascites)
Clinician‘s overall judgment
• good nutritional status
• moderate malnutrition
• severe malnutrition
Detsky et al, JPEN, 1984
27. ESPEN guidelines for nutrition screening
2002
Part 1
Kondrup J et al. ESPEN guidelines for nutrition screening 2002. Clin Nutr 2003
28. Part 2
Kondrup J et al. ESPEN guidelines for nutrition screening 2002. Clin Nutr 2003
29. Nutritional Assessment
Is the actual measurement of
nutritional state and has to be done
in patients that are considered to be at
risk by the nutritional screening
or
when metabolic or functional problems
prevent a standard plan being carried out
30. Normal body composition
• Normal body cell mass (BCM) is the major
determinant of an adequate nutritional state:
– Living, actively metabolizing part of the body
– Extra-cellular mass may increase
disproportionately in malnutrition, disease,
whereas fat free cell mass decreases
• Normal macronutrients, electrolytes,
trace-elements, vitamins
• Normal organ sizes
31. What can be measured?
• Fat body mass
Body fat percentage
Fat distribution (visceral fat)
• Lean body mass
Water: extra and intracellular
Body cell mass
Muscle mass
Bone
39. Anthropometric measurement
• Validation only partially performed
• Large inter-individual variability
• Good intra-individual variability if
the investigator is properly trained
40. Creatinine excretion in urine
• Creatinine excretion correlates with
lean body mass and body weight
• 18-20 kg of muscle produce 1 g
of creatinine
• Dietary protein sources contribute
up to 20% of excreted creatinine
• Urinary creatinine excretion
is proportional to skeletal muscle mass
(stable renal function; no dialysis
or hemofiltration)
43. Body fat distribution
and waist circumference
• Measured at the mid-point
between the ileac crest and
the lower rib
• Correlates strongly with
intra-abdominal adipose
tissue as assessed by CT and
MRI
• Upper body obesity defined
as a waist circumference:
– ≥ 102 (94) cm for men
– ≥ 88 (80) cm for women
45. ESPEN - GUIDELINES
Bioelectrical impedance analysis
Fat-free mass and
Total body water
1) Review of principles & methods.
Clin Nutr 2004; 23: 1226-1243
2) Utilisation in clinical practice.
Clin Nutr 2004; 23: 1430-1453
www.espen.org/education
46. Bioelectrical impedance
analysis (BIA)
• BIA allows the determination of
- FFM on the basis of TBW measurement
• in subjects without significant fluid and
electrolyte abnormalities when using appropriate
equations (age, sex, race)
• BIA in subjects at extremes of BMI ranges
(16-34 kg/m2) or with abnormal hydration
status is not reliable
• Disease almost always includes inflammatory
activity (ICW/ECW ratio decreases; TBW
increases; BIA unreliable)
47. Dual energy X-ray
absorptiometry (DEXA)
• Three-compartment
model
• Fat mass, free-fat
mass and bone
• State of hydration
may affect results
49. Creatinine excretion in urine
• Creatinine excretion correlates with
lean body mass and body weight
• 18-20 kg of muscle produce 1 g of
creatinine
• Dietary protein sources contribute up
to 20% of excreted creatinine
• Urinary creatinine excretion is
proportional to skeletal muscle mass
(stable renal function; no dialysis or
hemofiltration)
51. Muscle strength
• Is a good predictor of outcome:
– In chronic situations:
• Aging
• Organ failure (renal failure, COPD,
heart failue….
– In acute situations:
• Surgery or trauma
• Second hit (superimposed infection when
already subject to inflammatory activity)
58. Inflammatory and disease
activity
Disease always includes inflammatory
activity
• Clinical evaluation
- Pre-existing inflammation or disease
• Plasma Albumin levels
- Already significant when ≤ 35 g/L
• Cytokine levels (TNF-α, IL 6, ...)
• CRP
- Very volatile, is a rough correlations, but not
suitable for the individual patient
59. Serum proteins
• Albumin (T½): 20 days
• Transferrin (T½): 8-10 days
• Transthyretin (T½): 2-3 days
(Prealbumin)
• Retinol-binding protein (T½): ∼ 12 h
60. Wound healing is dependent of
endogenous substrates
Undernutrition
poor wound healing
(dehiscence, infections)
Loss body cell mass
Deficit endogenous
substrates for wound
healing.
68. How to measure food intake
• Bomb calorimetry of food before and after
meal (double plate method)
• Weighing of food before and after meal
• Quarter plate method
69. Quarter plate method
• Standard meal
• 2000 kcal
• 60 g protein
• 290 g CHO
• 70 g fat
70. Calculate energy and protein intake
– he eats ¼ of servings
• Standard meal
• 2000 kcal
• 70 g protein
• 280 g CHO
• 70 g fat
71. Calculate energy and protein intake
– he eats ¼ of servings
• Standard meal
• 2000 kcal
• 70 g protein
• 280 g CHO
• 70 g fat
• Daily intake
• Energy – 500 kcal
• Protein – 24 g
72. Calculate daily energy balance
• Energy balance EB:
EB = EI – TEE
EB = 500 – 1800 = -1300 kcal/day
73. Calculate daily need of supplements
• Energy deficit: 1300 kcal/day
• Protein deficit: 30.4 g day
Standard supplement (sipping)
= 150 kcal & 6 g Prot/100 ml
Recommendation
= 1000 ml of standard nutrition (e.g. sipping)
