Macronutrients II Flashcards
Also used in the synthesis of the porphyrin nucleus of hemoglobin
-a constituent of the bile acids
Glycine
A precursor of the neurotransmitter GABA
Glutamic acid
Water is drawn back into the capillaries by increasing the concentration of
Albumin
Common in protein deficiency when albumin levels are low
Edema
A severe protein deficiency impairs the body’s ability to produce adequate
Albumin
Serum albumin has a half-life of
18-20 days
Reflects protein status over the previous three months
Serum albumin
Serum pre-albumin has a halflife of only
2 to 3 days
Reflects the nutritional status as well as protein and calorie intake over the previous week
Serum pre-albumin
What is the RDA for protein in healthy people
0.8g / kg body weight
What is the AMDR for protein?
10%-35% of energy
Amino acids are used for energy if they are stripped of their
Nitrogens
When nitrogen intake equals nitrogen output
Zero nitrogen balance
If the body synthesizes more nitrogen than it degrades than we have a positive nitrogen balance and
Protein is added
We see positive nitrogen status in
Growing infants and children
Athletic training causes
Positive nitrogen balance
One in four children in the developing world is severely underweight by age
5
The cause of death in underweight children is often
Diarrhea and dehydration that accompanies infections
The most common deficiency in early life is
Protein deficiency
Who estimates that this condition plays a role in 5 million child deaths per year
Protein-Energy Malnutrition (PEM)
Characterized by severe, chronic, overall malnutrition
Marasmus
Marasmus kids are alert and ravenously hungry at first, but eventually lose appetite and become
Apathetic
Caused by a sudden and recent deprivation of protein
Kwashiorkor
Leads to severe edema and ascites, i.e. fluid accumulation in the abdominal cavity
Kwashiorkor
Kwashiorkor patients have cracked and peeling skin, sparse unnaturally blond or red hair, and an
Enlarged, fatty liver
The recommendation from the world cancer research fund is to limit red meat to
500g (18 oz) per week
Fats and oils are types of
Lipids
Hydrophobic and made up of carbon, hydrogen, and oxygen
Lipids
Solid at room temperature
Fats
What are the 5 classes of lipids?
Fatty acids, triglycerides, phospholipids, sterols, and fat soluble vitamins
What is the difference between saturated and unsaturated fatty acids?
Unsaturated has double bonds
Fatty acids with chain lengths of 4-10 carbons are found in significant quantities in
Milk
Structural lipids and triacylglycerides contain primarily fatty acids of at least
16 Carbons
Arachidonic acid is a precursor of
Prostaglandins
May be a bigger risk factor for heart disease than saturated fatty acids
Trans fatty acids
Increase LDL and decrease HDL
Trans fatty acids
The most common type of lipid
Fatty acids
The Alpha (α) end of a fatty acid contains a
COOH group
The Omega (ω) end of fatty acids contains a
Methyl group
Short chain fatty acids have less than
8 Carbons
Medium chain fatty acids have between
8-12 carbons
Long chain fatty acids have
Greater than 12 fatty acids
Partially hydrogenated oils are
Trans fats
What are the two essential fatty acids?
Linoleic acid and linolenic acid
Humans can not introduce double bonds into a fatty acid from carbon
10 and beyond
This is the basis for the nutritional essentiality of the
Essential fatty acids
The body also can not create double bonds in the
ω-3 or ω- 6 positions
Made up of 18 carbons with 2 cis double bonds
-A ω- 6 fatty acid
Linoleic acid
Made up of 18 carbons with 3 cis double bonds
-A ω-3 fatty acid
Linolenic acid
Linoleic acid and linolenic acid are building blocks for longer chain
ω-3 and ω- 6 fatty acids
Linoleic acid is a precursor for
Arachidonic acid (20C, AA)
Linolenic acid is a precursor for
Eicosapentaenoic acid-20C (EPA) and Docoshexaenoic acid-22C (DHA)
Compete for the same enzymes and their actions often oppose eachother
Linoleic and linolenic acid
What is the suggested ration of linoleic to linolenic acid?
4:1 (in the U.S. diet 10:1)
Assist and regulate immune and cardiovascular systems
Eicosanoids
Eicosanoids act as
Chemical messengers
Control dilation and constriction of blood vessels
- regulate BP
- an eicosanoid
Prostaglandins
Linoleic acid is classified as a
ω- 6 eicosanoid
Functions in inflamation
Arachiodonic Acid (AA)
Linolenic acid is classified as a
ω-3 eicosanoid
ω-3 derivative that functions in dilation of blood vessels
-an eicosanoid
EPA
ω-3 derivative that functions in visual and cognitive development
-an eicosanoid
DHA
Irritated and flaky skin, GI problems, and comprised immune system are symptoms of
Essential fatty acid deficiency
During infancy, babies may not have specific enzymes to make
AA and DHA
Particularly important for the brain development and formation of the retina
DHA
Has at least 47 different fatty acids not found in formula
Human milk
Conditionally essential for infants for growth, development of eyes, and nervous system development
Polyunsaturated FAs
Formula does not have
Cholesterol
The health benefits of fish oil are believe to be derived principally from
EPA and DHA (ω-3) derivatives
Flaxseed oil contains only
Alphalinolenic acid (ALA)
Must be converted into EPA and DHA
-thus only a small fraction has ω-3’s effects
ALA
We can increase HDL with
High MUFA intake
A high PUFA diet and a diet rich in ω-3 FAs is a good way to lower
LDL
Sucrose bonded w/ 6-8 fatty acids
-cannot be digested by lipases or colonic bacteria
Olestra
Interferes w/ vitamin A, D, E, and K absorption
Olestra
Cellulose, vegetable gum fibers, Maltrin, and Stellar are all
Fat substitutes
What is the AMDR for lipids?
20%-35%
We want no more than 10% of total calories to come from
Saturated FAs
