Transcript Nutrients & Assessments

NUTRIENTS
and
ASSESSMENT
Myrna D.C. San Pedro, MD, FPPS
NUTRITION
Combination of processes by which
the living organism receives & uses
the materials necessary for growth,
maintenance of functions & repair
of component parts
METABOLISM
All the changes in the foodstuffs
from absorption in the digestive
tract until elimination by the
excretory organs
Nutrient Requirement: the amount to
replace obligatory losses & support
synthesis of new tissues; varies by age,
sex, size & growth rate
Energy Requirement/Expenditure:
1.
2.
3.
4.
5.
Basal Metabolic Rate (BMR)
Specific Dynamic Action of food (SDA)
Body activity
Growth allowance
Losses per excreta
Basal Metabolic Rate (BMR)





Energy expenditure of an awake individual
at rest in a thermoneutral environment after
an overnight or 14 hours fasting
Most closely related to lean body mass
Factors: metabolic disorders, surgery,
infections, anorexia or fever; for example,
basal metabolism increases by about 10%
for each centigrade of fever
50-100% of resting metabolic rate in infants
and 20-25% in adults goes to maintenance
of temperature
In infants about 55 kcal/kg/day which
decreases to 25-30 kcal/kg/day at maturity
Specific Dynamic Action
(SDA)



The obligation to expend energy
to digest & assimilate food
Highest for proteins & lowest for
carbohydrates
About 5 kcal/kg/day



Body activity (exercise & physical
activity): average allowance during
the first year is 25 kcal/kg/day
Growth allowance: during the first 4
months is about 15-20 kcal/kg/day
which decreases to 12 kcal/kg/day at
the end of the first year
Fecal loss: 8 kcal/kg/day in the form of
unused fats & proteins
Thus, the energy requirement of the infant
or child is the level of intake which can
maintain appropriate
body size & composition
include deposition of new tissue
and the thermic effect of food
meet the energy required for physical activity
Daily Requirement
Approximately 80-120 kcal/kg
body weight for the 1st year
of life with subsequent
decreases of about 10 kcal/kg
body weight for each
succeeding 3-year period
Recommended Dietary Allowances
(RDAs, USA)



Other terms are Recommended Dietary
Intakes (RDIs, UK) and Safe Levels of Intake
(FAO/WHO)
The levels of intake of essential nutrients that
are judged by the Food and Nutrition Board,
based on scientific knowledge, to be adequate
to meet the known nutrient needs of
practically all healthy persons
An important element is that recommended
intakes must be adequate for population
groups implying that safety margins are
inherent in these recommendations
MAJOR NUTRIENTS
1.
2.
3.
4.
5.
6.
Carbohydrates
Proteins
Fats
Vitamins
Minerals
Water
Energy is provided by the following
1.
2.
3.
Carbohydrates:
60% (45-65%) of the diet
1gm provides 4 kcal
Proteins:
11% (9-15%) of the diet
1gm provides 4 kcal
Fats:
35% (25-45%) of the diet
1gm short-chain provides 5.3 kcal
1gm medium-chain provides 8.3 kcal
1gm long-chain provides 9 kcal
Carbohydrates’ Functions
1.
2.
3.
4.
5.
6.
7.
Readily available source &
supply most of the body’s
energy needs
Antiketogenic
Structure of cells
Store calories as glycogen
Convert to fat
Amino acid synthesis
Cellulose as roughage
Proteins’ Functions
1.
2.
3.
4.
5.
6.
Supply amino acids for growth &
repair of body tissues
Supply ions in acid-base balance
Part of hemoglobin, nucleoproteins,
glycoproteins & lipoproteins
As enzymes, hormones, antibodies &
cellular respiratory substance
Protective structure (nails & hair)
Source of energy when there is
shortage of fats & carbohydrates
Daily Protein Requirement
2002 Dietary Reference Intakes (DRIs)
Updates from the (US) Food and Nutrition
Board of the National Academy of
Sciences (gm/kg BW/day)
0-6 mo
---- (2.2, WHO)
1978 FNRI
Publications, Daily
Requirements of
Filipinos
(gm/kg BW/day)
0-5 mo
3.5
6-11 mo
3
1 to 3 yr
1.1
1-2 yr
2.5
4 to 13 yr
0.95 (1 for 7 yr WHO)
3-6 yr
2
7-15 yr
1.5
16-19 yr
1.2
14 to 18 yr
0.85 (0.75, WHO)
As a point of reference, 3 ounces of lean
beef, which is a serving the size of a deck
of cards, provides 30 grams of protein. A
cup of milk contains 8 grams of protein.
Essential Amino Acids




Essential nutrient: A substance necessary
for normal metabolic functioning but cannot
be synthesized by the body and must be
obtained from the diet
24 amino acids identified
9 are found to be essential for children:
histidine, isoleucine, leucine, lysine,
methionine, phenylalanine, threonine,
tryptophan & valine
Arginine, cystine & taurine are essential for
LBW infants
Evaluating Protein Quality
1.
2.
3.
Protein Efficiency Ratio (PER): Wt gained/gm
protein consumed; the U.S. FDA used the PER as
the basis for the % of the USRDA for protein on
food labels but PER was based upon the a. a.
requirements of growing rats, which are different
from humans
Biologic Value (BV) of protein: Amount of nitrogen
accumulated compared with nitrogen absorbed;
indicates effectiveness of utilization but does not
take into account certain factors influencing
digestion
Net Protein Utilization (NPU): Percentage of
nitrogen consumed that is retained by the body;
influenced by factors other than inherent a. a.
composition such as reduced digestibility caused
by overheating lowering protein value by
decreasing availability of several essential a. a.
Evaluating Protein Quality
4.
5.
Amino Acid Score (AAS): A chemical
technique measuring indispensable a. a. in a
protein and comparing values with a reference
protein; considered fast, consistent, and
inexpensive
Protein Digestibility Corrected Amino Acid
Score (PDCAAS ): Amino Acid Score w/added
digestibility component; current accepted
measure based on the amino acid
requirements of humans; limitations: takes no
account of where the proteins have been
digested and may also be considered
incomplete since human diets almost never
contain only one kind of protein
Fats’ Functions
1.
2.
3.
4.
5.
6.
7.
8.
9.
A concentrated & reserve source of energy
Physical protection for vessels, nerves,
organs
Insulate against changes in temperature
Structure of body tissues, cell membranes
& nuclei
Carry the fat-soluble vitamins (A, D, E, K)
Give appetite appeal
Aid satiety (delay emptying time of the
stomach)
Spare protein
Supply linoleic acid, the essential fatty acid
Essential Fatty Acids (EFAs)




Linoleic acid (LA) & linolenic or alpha-linolenic acid
(LNA or ALA) are the 2 EFAs; LA can be converted to
both arachidonic and linolenic acids
Necessary for growth, skin & hair integrity, regulation
of cholesterol metabolism, lipotropic activity,
decreased platelet adhesiveness and reproduction;
diets w/<1-2% cal will affect growth rate, cause dry
scaly rash w/ intertrigo and poor wound healing
LA is abundant in soy oil, sunflower, safflower &
sesame seeds, corn oil, and most nuts while LNA is
found abundantly in flax, small quantities in walnuts,
cold pressed canola oil, wheat germ and dark green
leafy vegetables
The right ratio of LA to ALA in the diet, about 3:1 or
2:1, is important; an imbalance may lead to a variety
of mental disorders, including hyperactivity,
depression, brain allergies, and schizophrenia
Omega-3 and Omega-6 Fats





Polyunsaturated fatty acids (PUFA) containing more
than one cis double bond
ALA (18:3n-3) belongs to the omega-3 family of fatty
acids while LA (18:2n-6) belongs to the omega-6
family; from these 2 EFAs can be manufactured other
(non-essential) omega-3 and omega-6 fatty acids
Important structural components of cell membranes,
that, when incorporated into phospholipids, affect cell
membrane properties such as fluidity, flexibility,
permeability and the activity of membrane bound
enzymes
Lowers LDL cholesterol & decreases CV disease risk
Can modulate the expression of a number of genes,
including those involved with fatty acid metabolism
and inflammation
Eicosanoids derived from DGLA, AA and EPA play critical roles in
immune and inflammatory responses by being formed into
prostaglandins and leukotrienes although EPA eicosanoids are
less potent inducers of inflammation, blood vessel constriction,
and coagulation than those derived from AA




DHA and AA are high in the phospholipids of brain
gray matter suggesting their importance to CNS
function such that depletion of DHA in the brain
can result in learning deficits
Also, EPA and DHA supplementation during
pregnancy has beneficial effects on long-term
cognitive development in children
DHA appears to be important for visual and
neurological development but it is not yet clear
whether feeding infants formula enriched with DHA
and AA enhances visual acuity or neurological
development in preterm or term infants
There is evidence, though, that human conversion
of EPA and, particularly DHA, is relatively
inefficient suggesting that EPA and DHA may also
be essential under some conditions
Vitamins



Organic compounds in minute
amounts that catalyze cellular
metabolism
16 vitamins, 8 of which are
considered necessary for human
nutrition: retinal, thiamin, riboflavin,
niacin, cobalamin, folacin, ascorbic
acid & vitamin D
There is presumptive evidence that
pyridoxine & tocopherol may be
necessary for infant nutrition
Minerals







Macrominerals
Sodium 1gm or
2mEq/kg
Potassium 1-2gm or
1.5mEq/kg
Calcium 0.6gm/day
Magnesium 150300mg/day
Chlorine 0.5gm/day
Phosphorus
Sulfur 0.5-1gm/day










Microminerals
Iron 1mg/kg/day
Iodine 34-45 mcg/day
Copper 0.5-1mg/kg/day
Fluorine 0.5-1mg/day
Zinc 3-5mg/kg/day
Cobalt 1-2mcg/day
Manganese 0.05-1.5mg/day
Chromium 0.02-0.10mg/day
Selenium 0.02-0.10mg/day
Molybdenum 0.050.15mg/day
Macrominerals





Sodium, Chloride, Potassium work together to
regulate the flow of fluids in the body & help
regulate the nervous system, muscle functions &
nutrient absorption in the cells
Calcium is needed for bone rigidity & helps in
blood clotting, muscle contraction & normal nerve
functions.
Phosphorous aids in all phases of calcium
metabolism & helps build strong bones & teeth
Magnesium helps regulate body temperature,
muscle contractions & the nervous system & helps
cells utilize carbohydrates, fats, and proteins
Sulfur helps in detoxification reactions & is present
in the amino acids in proteins & a component of
constituents of mucopolysaccharides & essential
compounds
Microminerals










Iron combines with protein to form hemoglobin
Iodine is needed by thyroid gland to produce thyroxine
Copper is necessary in the formation of hemoglobin
Fluorine helps reduce incidence of tooth decay
Zinc plays an important role in the formation of protein,
thus, assists in wound healing, blood formation and
general growth & maintenance of all tissues
Cobalt is a component of vitamin B12
Manganese is necessary for normal development of
bones and connective tissues
Chromium maintains normal glucose uptake into cells
& helps insulin bind to cells
Selenium w/vitamin E protects cells from destruction
Molybdenum is a component of xanthine oxidase and
aldehyde oxidase
Water





Essential for life
Two-thirds of body weight, 75-80% in
infants while 55-60% in adults
Daily consumption by a healthy infant
is 10-15% BW versus 2-4% BW in adult
Of fluid intake: water retention 0.5-3%,
evaporation from lungs & skin 40-50%,
fecal losses 3-10% & renal excretion
about 40-50% or more
Fruits & vegetables 90% water
ASSESSMENT OF NUTRITIONAL
STATUS OF CHILDREN
1.
2.
3.
4.
5.
History
Dietary history of mother & child
History of height & weight changes
Anthropometric indicators
Evidence of deviations from average
height & weight
Evidence of depletion of fat depots
Evidence of decrease in muscle mass
Change in psychic reaction
Reaction to infection
Evidence of specific deficiencies
ANTHROPOMETRIC INDICATORS OF
NUTRITIONAL STATUS
1.
2.
3.
Weight: index of acute nutritional status
Height or length: unaffected by excess fat
or fluid; assesses growth failure
Weight for height measurement: more
accurately assesses body build
A. Measure child’s height
B. Find age for which measured height is
on the 50th % on the growth curve
C. Child’s actual weight (numerator)
50th% wt based on age of plotted ht
(denominator)
4.
5.
6.
7.
Head circumference: influenced by nutrition
till age 36 mo; measurements < 5th% may
indicates chronic undernutrition during fetal
life & early childhood
Skinfold thickness(TSF): provides an
estimation of total body fat
Mid-arm circumference (MAC)/Mid-arm
muscle circumference (MAMC): with TSF,
determines muscle area & fat area
**MAMC = MAC – (3.4 x TSF)
Bone age: epiphyseal closure; percentage of
maturity attained indicates potential for
catch-up growth
8.
Growth Velocity (GV)
Evaluates change in rate of growth over a
specific time period expressed in cm/yr;
more sensitive way of assessing growth
failure or slowed growth
 Formula:
GV (cm) = H2 (cm) – H1 (cm)
T (yr)
where
H1 = initial height in centimeters
H2 = height at next measurement
T = period between two
measurements in years

9.





Body Mass Index (BMI)-for-Age
An effective screening tool specific for age
and gender but not a diagnostic tool
Formula: Weight (kg)/[Height (m)]2
Calculation: [weight (kg)/ height (cm)/height
(cm)] x 10,000
BMI-for-age cut-offs:
> 95th %
Overweight
85th - < 95th % Risk of overweight
< 5th %
Underweight
BMI-for-age correlates w/ clinical
risk factors in CVS disease such as
hyperlipidemia, elevated insulin &
high blood pressure during middle age
Can you see risk?
A
Overweight
Age=3 y 3 wks boy
Height=100.8 cm
Weight=18.6 kg
BMI=18.3
BMI-for-age
= >95th %
B
Normal
Age= 4 y 4 wks
girl
Height=106.4 cm
Weight=15.7 kg
BMI=13.9
BMI-for-age
= 10th %
C
At risk for overweight
Age=4 y girl
Height=99.2 cm
Weight=17.55 kg
BMI=17.8
BMI-for-age
= between 90th –95th %
BMI-for-Age
A
C
B

During early childhood, BMI decreases reaching a nadir
(the so-called rebound point) between 4 and 7 years of
age, then increases to 20 years of age reflecting the
normal changes in body composition during puberty.