definition of nutrition
science that studies all interactions between living organisms and food
where do nutrients and energy come from? what are essential nutrients?
provided by food, essential nutrients must be supplied in the diet
How does the canadian diet differ in the past and present?
Past
more time spent obtaining
food ingredients
more time spent
preparing foods
less variety
consumed seasonal foods
family sat together to eat
meals at a slower pace
reasonably-sized portions
of food
Present
purchase convenient and
processed foods
spend
how does the primary concern about the canadian diet differ from past to present?
Primary concern in the past was obtaining all
the nutrients needed for good health.
Today, primary concern is balancing
consumption of calories to prevent obesity
and chronic diseases associated with it, while
obtaining essential nutrients.
What are the top 3 leading nutrition related causes of death
heart disease, cancer, stroke
phytochemicals, zoo chemicals
come from plants, come from animals
fortified food
foods to which nutrients have been added too
six classes of nutrients are
lipids, proteins, carbs, water, vitamins and minerals
calories per gram of macros
carbs and protein - 4
fat - 9
alcohol - 7
What do carbs include? Are they organic?
starches, sugars, fibre - yes
does fibre provide energy?
no
what are lipids?
concentrated source of energy, fat, oils - triglycerides is a type of fat that is found, it's made of fatty acids
what are proteins?
required for growth, maintenance and repair of body - made of different amino acids
what do micro nutrients do? what is a micro nutrient?
provide no energy by are necessary for proper functioning of the body, these are required in small amounts
is water a macro??? how much body % does it make up?
yes, does not provide calories, makes up 60%
How do macros/micros provide energy for the body?
Macronutrients and micronutrients work together
to help the body to stay healthy.
Biochemical reactions in the body help to
release the energy contained in carbohydrates,
fats and proteins.
Energy is used to maintain body functions and
fuel physical work.
what is weight due to? How do nutrients help form and maintain the shape of the structure?
water, fat, protein
form ligaments, tendons, bones and teeth
what are reactions called in the body??
metabolism
what is the proper regulation of metabolism called? What helps this process?
homeostasis
Enzymes (proteins) + micronutrients speed up or slow down metabolic reactions
Water helps to regulate temperature.
what does malnutrition mean??
eating too little or too much of one or more nutrient
under nutrition
overnutrition
eating not enough
eating excess
both are malnutrition
diet is impacted by cultural and personal variables such as..
Religious dietary laws
Ethnic menu preferences
Social acceptability
Personal preference
Psychological and emotional factors
Health concerns
food availability depends on:
Geography
Transportation and mobility
Available income
Food storage and preparation equipment
Health status
what is nutrient density???
is a measure of the nutrients a food provides compared to its energy content
how do you choose a healthy diet?
Different interactions between different foods and nutrients ? these could be positive (enhancing nutrient utilization) or negative (inhibiting use), moderation, portion control
observational studies include... and demonstrate,,,
epidemiology( study of diet), correlations
what questions should you ask to see if the information is reliable?
does it make sense?
where did it come from?
is the info based on well-designed accurately-interpreted research studies?
who will benefit?
has this product stood the test of time?
what does cars stand for??
Credibility: authorship, organization, peer review
Accuracy: timely-ness, completeness
Reasonableness: fairness, objectivity, moderate-ness
Support: bibliography, corroboration, external consistence
what are the red flags for junk science?
Promise a quick fix
� Dire warnings; dramatic statements
� Sounds too good to be true
� "Good" foods and "bad" foods
� Selling a product
� Sometimes use "science" to support claim
Simple conclusions from a complex study
Statements refuted by reputable sci
What are DRIs, what are they used for?
used for planning, assessing diets, they vary according to life stage and gender, promote good health and reduce disease
what are the 2 types of recommendations?
nutrient based - amount of nutrients needed
food based - dietary pattern recommended
what have DRIs been developed for??
energy (macros)
water-soluble vitamins (b/c)
fat-soluble vitamins (a,d,e)
minerals
water
what is an EAR?
the estimated amount of a nutrient required to meet the needs of 50% of people within a particular sex and life-stage group
what is an RDA?
the recommended target intake of a nutrient for an individual
EAR + 2SD = RDA
NOT 50% OF THE POP, BUT 98
What is an adequate intake?
recommended specific amount of a nutrient for an individual
what is the tolerable upper intake level?
maximum daily intake of a nutrient unlikely to cause adverse health effects
what 2 recommendations do DRIS make for energy?
Estimated Energy Requirement (EER) - used to calculate kcalorie intake needed to maintain body weight
Acceptable Macronutrient Distribution Range(AMDR) - range for healthy intake
carbohydrate (45 to 60%)
protein (10 to 35%)
fat (20 to 35%)
what does page one of the canada food guide show?
Rainbow graph
Veggys and Fruit (green)
Grain products (yellow)
Milk (blue)
Meat (red)
Length corresponds to servings
High fibre/ veggies and fruit have been known to reduce chronic diseases (cardiovascular and cancer)
Milk - prevents bone diseases
Meat -
page 2 of canada food guide
number of servings, states the purpose of food guide - meeting nutrient needs, reduce obesity and chronic disease like type 2 diabetes, heart disease, cancers, osteoporosis
page 3 of Canada Food Guide
defines portion size
KNOW PORTIONS FOR AGE
page 4 of food guide
additional statements about food choices like Low-fat, low sugar - reduces obesity
low salt - reduces high blood pressure
Advised to consume dark green and orange veggies - these are rich in folate and Vitamin
To ensure fibre - make sure half of your grai
page 5 of f.g
specific recommendations are made for pregnant women, kids, elderly
page 6 of food guide
how to improve diet, how to become more physically active
foods to limit
what are the food label requirements in canada?
name of product
weight of product
date by which the product should be sold (if
perishable)
name of manufacturer, packager or distributor
list of ingredients
nutrition facts table
what has to be incorporated on the ingredient list?
all items must be listed
highest weighted items listed first
additives, food colours and flavourings must be
listed
serving size
number of kcalories (calories) per serving
total amount of fat and amounts of saturated fat,
trans fat and cholesterol per ser
what is a % Daily Value?
a percentage (%) of a standard called
Daily Value (DV)
goal: allows consumers to compare
products
5% DV indicates
15% indicates
low value
high value
what are:
Nutrient-content claims?
disease-risk reduction claims?
nutrient-function claims?
low fat, sugar free
lowering blood cholesterol
roles of nutrients - aids bone development
natural health products director of health canada indicates...
vitamin and mineral supplements
natural health products
herbal remedies
traditional medicines
homeopathic products
labels on health products must include..
product name
product licence holder
Natural Product Number (NPN) and Homeopathic
Number (DIN-HM)
medicinal and non-medicinal ingredients
dosage form
recommended use or purpose
risk information
dietary intake can be assessed through..
24-hour recall
food diary or food intake record
food frequency questionnaire
diet history
what are the challenges in determining dietary intake?
unable to recall exactly what was eaten
under- and overestimation of portion consumed
weekend intake differ from that during the week
lack of commitment to recording intake
intake not a typical day
what are nutrient analysis tools used to determine if dietary intake is adequate?
Eating Well with Canada's Food Guide
food labels
nutrient content tables
computer programs
what additional info is useful and needed to assess nutritional health??
info about physical health - anthropometric measurements, such as height
and weight
medical history and physical
exam
laboratory measurements
what are the stages of nutrient deficiency?
Inadequate Intake: assess nutrient intake - medical history, physical exam and lab tests, assess problems due to poor nutrient absorption, increased need or increases losses
Decreased stores and tissue levels: lab tests - assess nutrients levels in blood,
what are food disappearance surveys??
means of estimating the food available to a population and identifying trends in diets
what are tissues organized in?
tissues organized from cells of similar functions
what makes up organs?
tissues of specialized function
what are the 4 types of tissue?
muscular, skeletal, endocrine, integumentary, digestive
what is digestion?
what is absorption?
Digestion: process of breaking food into components small enough to be absorbed by the body
Absorption: process of taking substances into the interior of the body
what is the GI tract composed of?
hollow tube consisting of the
mouth, pharynx, esophagus, stomach, small intestine,
large intestine and anus
what is transit time? what is it effected by?
amount of time it takes food to pass the length of the GI tract - effected by comp of diet, physical activity, emotions, medications, illnesses
what are feces?
body waste, including unabsorbed food resiude, bacteria and dead cells
name the functions of the mouth, sal gland, pharynx, stomach, esophagus, pancreas, gallbladder, small intestine, large intestine and anus
Mouth - chews, mixes with salvia
Salivary glands - starch digesting enzyme
Pharynx - swallows chewed food
Esophagus - moves food into stomach
Stomach - churns and mixes food, secretes acid and protein-digesting enzyme
Liver - makes bile, aids in digestion
What are the components of the gut wall?? What do they do?
4 layers of tissue
Mucosa: lining the lumen, protective layer, responsible for the absorption of the end products of digestion - these cells have a short lifespan, because they have high reproductive needs (they die quickly) they need a lot of nutrients a
how is mucus used by the GI tract?
viscous material produced by goblet cells, mucus moistens and lubricates and protects the tract
what do enzymes do?
protein molecules speed up chemical reactions
salivary amylase
mouth, breaks down starch into smaller carbs
rennin
stomach - causes milk protein to curdle
pepsin
breaks preteens into polypetides and amino acids
trypsin
pancreas - breaks proteins and polypeptides into shorter polypeptides
chymtrypsin
pancreas breaks proteins and poly peptides into shorter polypeptides
carboxpeptidase
breaks polypeptides into amino acids
pancreatic lipase
break triglycerides into monoglycerides, fatty acids and glycerol
pancreatic amylase
breaks starch into shorter glucose chains and maltose
lipase, sucrase,lactase, maltase
monoglycerides into fatty acids,sucrose into glucose and fructose, lactose into glucose and galactose, maltose into glucose
gastrin
stimulates secretion of HCl and pepsinogen by gastric glands in stomach and increases gastric motility and empying
somtostatin
inhibts : stomach secretion, motility and empyting, pancreatic secretion absorption in the small intestine, gallbaldder contraction and bile release
secretin
inhibits gastric secretion and motility, inceases output of water and bicarbonate from the pancreas, increases bile output from the liver
CCK
stimulates contraction of the gallbladder to expel bile, increases output of enzyme rich pancreatic juice
gastric inhibitory peptide
inhibts gastric secretion and motiliity
explain the GI tracts role in immune function
the go tract limits the absorption of toxins and disease causing organisms
phagocytes
engulf invaders
lymphocyes
detect antigens and produce antibodies
antibodies
binds to invading antigen and destroys them, antibody fights one specific antigen, antibodies remember antigens
Mouths role in digestion
Saliva in the mouth moistens food.
Saliva contains salivary amylase
which helps to break down carbohydrates
Saliva contains lysozymes, which help to inhibit bacterial growth in the mouth.
Chewing mechanically breaks food down,
increasing the surface area
role of pharynx and esophagus in digestion
Pharynx
Food and fluid pass through it
Air passes through on way to lunges
We start swallowing by choice, then it becomes involuntary
Air passage blocked by epiglottis
Esophagus
Tube that passes through the diaphragm
Food moved along by contractions of sm
what is the role of the small intestine?
Main site of digestion and food absorption
6 m long - 3 segments
First 30cm: Duodenum, next 2.4 m is the jejunum, last 3.3 is the ileum
Large circular folds increase surface area in contact with nutrients
Inner surface is covered with villi
Villi covered
what does the brain have to do with digestion?
Churning and how much gastric juice released is regulated by nerves and hormones
Signals come from brain, stomach and small intestine
Thought, smell, taste, sight - brain sends signals that stimulate gastric motility and secretion, prepares stomach
Food e
Duodenum: secretin and CCK
Secretin: + pancreas to secrete pancreatic juice and
liver to secrete bile into gallbladder
CCK: signals pancreas to secrete digestive enzyme
and causes gallbladder to contract and release bile
pancreas and the secretion of pancreatic juice
Bicarbonate ions: neutralize acid in chyme
Pancreatic amylase: breaks starch down into sugars
Trypsin/chymotrypsin: break protein down
Lipases: break fat down
what does the gallbladder do?
Secretes bile: produce in liver, and stored in
gallbladder
Bile needed for fat digestion and absorption
what does the large intestine do??
The large intestine does not
participate in digestion.
The large intestine contains
the colon and the rectum.
The large intestine can absorb
water and some vitamins and
minerals.
Microflora have an important
role
diffusion
higher concentration to lower concentration (move down the concentration gradient) - doesn't require energy
Facilitated Diffusion
the movement of substances across a cell membrane from an area o high concentration to an area of lower concentration with a carrier molecule - no energy required
active transport
requires carrier model and input energy, moves across concentration gradient from lower to higher concentration- starch, amino acids
TPN
feeding into a vein
toward the heart
veins
away from the heart
arteries
hepatic portal circulation
the vein that transports blood from the GI tract to the liver ? nutrients are processed here before they enter the rest of the circulation (gatekeeper)
Some nutrients are stored in the liver, some changed to different forms and others pass through
Modulat
absorption of fats
In small intestine, fats put into chylomicrons.
Chylomicrons pass from intestinal mucosa into the lacteals, which drain into larger lymph vessels
Lymph vessels from the body drain into the thoracic duct
what is a metabolic pathway??
Metabolic pathways are a series of reactions needed to transform food into a final product that can be used by body
catabolic pathway
release energy trapped in chemical bonds, requires enzymes
what is atp??
Macros can produce ATP from the catabolic pathway called cellular respiration
First they must be broken down into glucose, fatty acids and amino acids
They can then be metabolized, producing atop with carbon dioxide and water
cell currency
cell resp
In cell resp, o2 brough into the body is used and co2 is released - c02 is transported to the lungs where it is exhaled
Without o2, only glucose can produce atp
When 02 is availbe glucose, fatty acids, amino acuds can be broken down to 2 carbon units that
what do the kidneys, nephrons and glomerulus do??
Primary source of exretion of water, nitrogen-containing wastes from protien and other metbolic wastes and excess minerals
Nephrons - functional unit of kidney which performs the job of filtering the blood and maintaining fluid balance
Glomerulus -capilla
what forms the basis of most modern diet patterns??
carbs
what is the difference between whole foods and refined carbs?
whole foods are freh fruit, dairy, whole grains
refined carbs are separated from vitamins, minerals etc
what are the three layers of the whole grains and what do they contain?
bran layer: good source of fibre and vitamins
germ: good source of veggie oil and vitamin E
endosperm: contains starch and some protein
what does enrichment mean?
when refined trains sold in canda may be enriched with thiamin, riboflavin, niacin and iron and fortified with folate
what are added sugars?
sugars and syrups that have been added to foods during processing or preparation
what is low nutrient density?
refers ti finds that contribute energy but few other ingredients
What are the 3 monos and where are they found?
glucose - plants and animals
galactose - mammalian milk
fructose - plants, fruit
what are the 3 dis and what molecules make them??
Maltose = 2 glucose
Sucrose = glucose + fructose
Lactose = glucose + galactose - only made in mammals breast tissu
what are the complex carbs and where are they found?
glycogen - animals
starches (amylopectin, amylose), fibre (cellulose) - plants
what are oligos and ploys??
Oligosaccharides: short chains of less than
ten monosaccharides.
- Polysaccharides: long chains of
monosaccharides. Include glycogen found in
animals and starch and fibre found in plants.
what are the steps of carb digestion/absorption
1. Mouth: Salivary Amylase breaks down starch into polysaccharides
2. in the stomach, salivary amylase is inhibited by acid - no digestion
3. in the small intestine most starch digestion and breakdown of disaccharides occurs, here pancreatic amylases cont
lactose intolerance
causes, symptoms, treatment, consequence of not consuming enough dairy
Not enough of the enzyme lactase in the small intestine to digest milk sugar lactose
Undigested lactose goes to LI - draws in water - produces gas and acid
the symptoms are abdominal distension, flatulence, cramping and diarrhea
it can be caused by the ge
what is glucose in the body used for??
energy for bodily functions, energy during excersise, some cells like red blood cells and the nervous system need it for energy
what is the basic structure of cell reps?
Glucose is metabolized through cellular respiration
(aerobic metabolism) to produce energy for the cell
in the form of ATP
� 6 molecules of oxygen + 1 molecule of glucose =
6 molecules of CO2 + 6 molecules of H2O + 38 ATP
insulin is secreted when....
secreted in response to a incline in blood glucose levels
glucagon is secreted in response too...
decline in blood glucose levels
what is gluconeogensis??
the making of new glucose
Glucose supplied by a metabolic pathway called gluconeogenesis - occurs in liver and kidney, energy requiring process that forms glucose from 3-carbon molecules which come primarily from amino acids derived from protein breakdown
what is the process of carb and fat breakdown??
Carbs needed for metabolism of fat
If carbs are limited, fat can't be broken down
Fatty acids are broken down in CoA - can't be metabolized unless it has a 4-carbon oxaloacetate
If carbs are limited liver converts it into compounds known as ketones which
what does diabetes lead too??
blindess, renal failute
what are the 3 types of diabetes and their causes
Type I Diabetes: autoimmune disease
- the body's own immune system destroys insulinsecreting
cells. Insulin is no longer made.
� Type 2 Diabetes: cells have decreased
sensitivity to insulin and there is a decrease in
insulin production.
- Usually in adult
what are the immediate symptoms of diabetes??
Immediate symptoms:
- excessive thirst, frequent urination, blurred
vision, weight loss.
what are the long term complications of diabetes?
damage to the heart, blood vessels, kidneys,
eyes, and nervous system. Infections are
more common in patients with diabetes, and
amputations may be necessary.
what is the treatment of type 2 diabetes?
� Goal:
- keep blood glucose levels within normal range
� Treatment:
- Consistently healthy diet, regular intake of small
meals, and regular physical activity
- Medication if needed
� Insulin or oral medications
what is the glycemic response and glycemic index??
Glycemic response is how
quickly and how high blood
glucose rises after
carbohydrates are consumed
� The glycemic index is a
ranking of how a food affects
the glycemic response
(relative to glucose).
how do carbs relate to heart disease?
Diets high in sugar or refined
carbohydrates have been shown to raise
blood lipid levels and can lead to an
increase in heart disease.
� Diets high in whole grains have been
found to reduce the risk of heart disease.
how do carbs cause tooth decay?
Cavities
Bacteria that live in the mouth form colonies - plaque
Bacteria metabolize from carbs, produces acid, dissolves enamel
Metabolize form refined and unrefined
Sucrose causes this to happen rapidly
Starchy foods that stick to teeth
Frequent snacking
do carbs effect body weight??
it's more the fat added that effects body weight
explain carbs and bowel disordes
Whole grains, fruits, veggies - fibre & resistant starch
Can relieve/prevent bowel disorder
Reduce constipation
Excess pressure of constipation produces hemorrhoids - swelling of veins in the rectal area
Also believed to cause weak spots in the colon to b
describe carbs and cancer
Indigestible Carbs and Colon Cancer
Cancer effects how cells behave
Development from genes but also from carcinogens from diet, tobacco smoke or air pollution
Characteristics of Cancer Cells
Cells become mutated and they reproduce without restraint and gr
what is the rda for carbs?
what is the amir for carbs?
what is the AI for fibre
130g
45-65%
38g men, 25g women
definition of DF
Edible carbohydrate polymers with 3 or more
units, which are not hydrolysed by the enzymes in
the small intestine of humans:
1.Naturally occurring in food
2.Obtained from food material and have a
physiological benefit to health
3. Synthetic carbohydrate p
what are the different types of resistant starch??
Not all resistant starches are the same. There are 4 different types.
Type 1 is found in grains, seeds and legumes and resists digestion
because it is bound within the fibrous cell walls.
Type 2 is found in some starchy foods, including raw potatoes and g
what contains dietary fibre, where is it found??
what does insoluble and soluble firbre mean??
Total fibre on a food label is the combined
amount of functional fibre and dietary fibre
found in the food.
� Soluble fibre dissolves in water and can be
found in oats, apples, and beans.
� Insoluble fibre does not dissolve in water
and can be found in wh
physicochemical properties of DF
� Solubility in water
� Viscosity/Gel-forming capacity
� Water-holding capacity
� Binding ability
� Bulking ability
� Fermentability
importance of the microbiota in human biology
immune system development, gut function, exclusion of pathogens, gut tissue development, nutrient acquisition, host metabolis,
decreases heart disease, obesity, chronic inflammation, colon cancer, diabetes, allergies, autoimmune diseases
what do short chain fatty acids do??
increase satiety and hunger, increase insulin sensitivity, increase barrier function, decrease inflammation
Primary energy source for colonic cells
� Anti-carcinogenic as well as anti-inflammatory properties
� Improves intestinal barrier function
� Induce
what are prebiotics??
According to Gibson et al., 2010:
"A selectively fermented ingredient that
results in specific changes in the
composition and/or activity of the
gastrointestinal microbiota, thus conferring
benefits upon host health''
what are some things to consider with prebiotics
Neither FDA nor EFSA have approved health claims for
prebiotics.
� However, by providing non-digestible carbohydrates to
the large intestine, evidence exists that they do influence
gut microbiota composition and especially metabolism.
� There are some sub
what are problems with the prebiotic concept
1)Based on an outdated 'good versus evil' perspective.
2) Neglects that it might be more important to support the
whole community and its diversity instead of specific
members.
3) Key metabolic benefits of prebiotics do not rely on a
specific fermentation
how does modern lifestyle deplete our microbiome
diet, sanitation, antibiotics, c-sections and formula
lipid function in body
define shape, provide stored energy, insulate the body from temp changes, protect internal organs against physical shock
- lubricates body surfaces such as mucous membranes of the eyes
amdr for fat
20-35%
what is a triglycerides
major form of lipids in food and in the body, consist of three fatty acids attached to a glycerol molecule
double bond numbers in
saturated fatty acid
monounsaturated fatty acid
polyunsaturadted fatty acid
0, 1, more than one
difference between cis configuration and trans fat configuration
hydrogens on same side
hydrogens on opposite sudes
what are the various components of phospholipids??
Phospholipids are lipids attached to a phosphate
group.
Synthesized in the body
Are a very small part of the diet
Are soluble in water
Act as emulsifiers (detergents, help to solubilize other
lipids in blood)
Have a structural and functional role in the b
what is a sterol???
Sterols are a type of lipid found in plants and animals.
Cholesterol is a type of sterol found only in animals.
Diets high in cholesterol (from animals) can increase the
risk of heart disease.
Plant sterols can help reduce cholesterol in the body.
what is cholesterol and what are the 5 major classes??
Parent compound for steroid hormones
Cholesteryl esters are stored as precursors for steroid
hormones, i.e. adrenal gland and corpus luteum -
ovaries
5 major classes:
Androgens
Estrogens
Progestins
Mineralcorticoids
Glucocorticoids
what are bile acids??
Formed from cholesterol
-Once conjugated with taurine or
glycine (in liver) they are secreted in the bile
-Solubilize phospholipids and cholesterol
(detergents)
- Aid in digestion and absorption of fat and fat-soluble vitamins in the intestine
what is the biological role of fatty acids???
PUFAs...
EFAs...
FAs and ___ ......
PUFAs help to regulate blood pressure and
blood clotting.
Essential fatty acids are important for growth,
skin integrity, fertility and the structure and function of cell membranes
Fatty acids and glycerol can be used to produce energy in
the form of ATP.
what are eicosanoids made from??
omega-3 and omega-6 fatty acids
can essential fatty acids be made by the body?? what is their function??
- Cannot be made by
body
- Essential fatty acids
needed for: growth,
skin integrity, fertility,
nerve and brain
function, and the
structure and function
of cell membranes
what 2 acids are the n-6 acids?? What are sources of these???
Omega-6 (n-6) fatty acids:
Linoleic acid
- Found in vegetable and nut oils
- Corn, soybean, and safflower oil
-Main n-6 dietary fat
Arachidonic acid
- Found naturally in animal tissues (meat, poultry)
- Most of it is made from linoleic acid
what is lonolenic acid, where oes it come from? What are the 2 acids that this includes. where do they come from??
Linolenic acid: flax seed, canola oil
Eicosapentanoic acid (EPA)
Docosahexanoic acid (DHA)
- Fatty fish - from cold water
-Fish oil supplements
- Supplementing animals or poultry
- Single cell organisms
biotechnology
what are the functions of EPA and DHA
Eicosapentanoic acid (EPA):
May reduce risk of death from heart attack
Decosahexanoic acid (DHA)
Critical for development of central nervous system
and retina of eyes
Helps the immune system
what are the essential fat requirements???
Linoleic acid: 12 g/day for women and 17
g/day for men.
5-10% of energy
Alpha-linolenic acid: 1.1 g/day for women, 1.6
g/day for men
0.6-1.2% of energy
Linoleic: alpha-linolenic = 5:1 to 10:1
what do lipoproteins do, how are the created, what do they help transport?
- transport particles for water insoluble lipids
- lipoproteins are created by combining lipids, phospholipids and proteins
- lipoproteins help transport triglycerides, cholesterol and fat-soluble vitamins from the SI and stored lipids from the liver
Blood Lipids include.... what are their functions?
Blood lipids include:
Chylomicrons: transport dietary fat from intestine
to tissues
VLDLs: very low-density lipoproteins; transport
lipids (mainly TGs) synthesized in the body to
tissues
LDLs: transports cholesterol to body
"bad cholesterol"
HDL: transpor
what 5 components increase the risk of cardiovascular disease?
High total cholesterol
High LDL cholesterol
Low HDL cholesterol
High LDLD-C/HDL-C ratio
High TG (and high VLDL)
what is cardiovascular disease??
Dysfunction of the heart or blood vessels
Can result in heart attack or stroke
Main cause: atherosclerosis
Slow and progressive development
what lifestyle factors influence CVD
q Being overweight
q Physical inactivity
q Smoking
q High blood pressure
q Elevated blood lipids
q Diabetes
q Stress
q Age
q Gender
q Family history
what do n-6 polyunsaturated fatty acids decrease chances of CVD?? what are sources of them??
decrease holesterol synthesis in liver,
decrease LDL cholesterol
sources: plant and veggy oils,
how do no n-3 acids decrease CVD?
decrease blood triglyceride, decrease VLDL triglycerides, decrease formation of blood clots
increase HDL cholesterol when combined with moderate exercise
- help maintain a normal heart beat
monounsaturated fatty acids and CVD
decrease LDL choelsterol, doesn't affect HDL cholesterol, good source of olive oil, veggy oils and animal fat
Diets high in high in saturated fats
decrease the removal of LDLs from the blood, promote the synthesis of cholesterol in the liver, contribute to the formation of plaques that can block arteries, increase TG levels
high intake of trans fat increase..., decrease....
increase LDL, Decrease HDL
what are Conjusgated Linoleic acid and Vaccenic acid, what do each reduce, where are they found
- trans fat found naturally in our diet
ANIMAL STUDIES
CLA: inhibit growth and metastasis of cancer, no effect on blood lipids, not on nutrient fact panels
VA: reduces elevated LDL, VLDL and inflammation
what are dietary factors that may reduce the risk of heart disease?
Consuming omega-3 and omega-6 polyunsaturated
fats
Consuming monounsaturated fats
Consuming plant foods, including
fruits and vegetables, whole grains
and legumes
Adequate intake of B vitamins homocysteine
Moderate alcohol consumption
how does fat affect cancer??
what does n-3 fatty acids do??
high intakes increase tumour growth as well as the tumours ability to spread
n-3 decrease tumour growth in animals
dietary fat is both a tumour ___ and ____
promoter and initiator
how do DHA and EPA decrease human cancer cells???
they could change the composition of the cell and membrane
they could recude growth signals, hormone and those in the cell
they could increase death of tumour cells
how is alcohol produced, what is the cal/g?
fermentation of carbs, 7 cal/g
what is the metabolism of alcohol like?
quickly absorbed, food slows down the absorption, enters blood stream quickly
causes dehydration, alcohol lost through lungs used to estimate blood alcohol
it's metabolized by the liver fast
what is alcohol dehydrogensase??
products produced promote fat syntheses
what ia microsomal ethanol oxiding system
reactive oxygen species produced in alcohol metabolism
alcohol metabolism steps 1-5
1. alcohol dehydrogenase breaks down alcohol to produce acetaldehyde
2. acetaldehyde is toxic and is degrade to produce acetly-CoA
3. breakdown of alcohol and acetaldehyde releases electrons that can be used to produce atp, but also results in changes tha
whats are the factors that affect blood alcohol levels?
weight
gender
food
drinking rite
type of drink
what is the rate of alcohol metabolism
about .5 alcohol/hr
alcohol in blood increases if exceeds the rate of breakdown
what does the rate of alcohol breakdown depend on?
health, genetics, body comp, gender, age, frequency of alcohol consumption
fasting vs fed state
what are the acute edicts of alcohol consumption??
liver breaks down 15ml etOh/h
(etOH = 150ml of wine, 350 ml of beer, 50 ml of distilled liquor)
when alcohol intake exceeds the ability of liver to break it down, alcohol intoxication or alcohol poisoning can occur
what happens when alcohol is consumed during pregnancy?
alcohol readily enters breast milk, concentrates within 1 hour of consumption, decreases milk production , flavours milk
what are the long-term effects of alcohol use??
- malnutrition
- decreasing overall nutrient intake
- causes primary malnutrion: low intakes of carbs, thiamin, vitamins A/C
- causes secondary malnutrition by interfering with nutrient absorption, storage, metabolism and excretion
- inflammation of GI or
what are some benefits of moderate drinking??
- lowest mortality
- reduced risk of heart disease and stroke,
- decrease risk of CVD (higher HDL, lower fibrinogen)
- antioxidant activity
- decrease stress
what are the differences between plant and animal sources of proteins??
animals - B vitamins, minerals, iron zinc, calcium - also have saturated fat
plant - b vitamins, iron, zinc, finer and calcium - less absorbale
What are amino acids??
What are Essential Amino Acids?
What are conditionally essential AA???
building block of proteins
cannot be synthesized by the human body in sufficient amounts
conditionally essential AA are essential under certain conditions
transamination
When a nonessential amino acid is not
available from the diet, it can be made in the body by the process of
what are peptide bonds, where are they formed??
chemical bonds that kink AA together - formed between the acid grip of one AA and nitrogen group of the next AA
protein is made of one or more poly peptide chains folded into 3 dimensional shape
the final shape of a protein determines...
what happens if this is altered
function
function may be altered
Steps of Protein Digestion
1. In the mouth, chewing begins the mechanical breakdown
2. in the stomach hydrochloric acid and the enzyme pepsin begin the chemical digestion - hydrochloric acid breaks down protein structure and activate pepsin
pepsin - breaks proteins into short polyp
what does protein digestion have to do with food allergies??
Food allergies are triggered when a protein from the diet
is absorbed without being completely
digested.
n Proteins from milk, eggs, nuts, wheat,
soy, fish and shellfish and peanuts are
common causes of food allergies
n A rapid, severe allergic reaction i
what is the amino acid pool
what is it used for??
all AA in the body tissues and fluids that are available for use by the body
energy production, synthesis of glucose or fatty acid, synthesis of non protein molecules containing nitrogen
protein synthesis
stretches of ___ called ____ dictate _____
DNA, genes, type of protein synthesized
describe transcription and translation
Transcription: process of copying the information in DNA to a mRNA
Translation: process of translating the mRNA code into the AA sequence of a polypeptide chain
1. copying/transcribing DNA code from the gene into the molecule of messenger RNA - TRANSCRIPT
amino acids must be ___ before used for ____
deaminated before being used for energy
after deamination the carbon compounds can be used for:
supply glucose via gluconeogensis
to provide energy: glucneogensis in liver, conversion to COA which enters the krebs cycle
to synthesize fat for storage through conversion to COA
What the functions of protein??
Provide structure to individual cells and whole body
Parts of a cell Ie cell membrane,cytosol, organelles
Body structures: skin, hair muscle
Collagen: part of bones and teeth
Enzymes speed up metabolic reactions.
Transport proteins move substances in and
what are protein function in regards to muscles, hormones and PH
contractile proteins help the muscles move (actin and Myosin)
hormones are chemical messengers such as insulin and glucagon
proteins help to regulate fluid and acid base balance - protein pumps in cell membrane
- proteins in blood
what is PEM?
is a term
that covers a range of protein deficiency
conditions that may include only protein
deficiency or protein deficiency plus energy
deficiency
what is kwashiorkor??
is a pure protein deficiency.
- Due to low protein, high fibre diet for first child
when 2nd child born
- See bloated abdomen
due to fat and fluid accumulation in liver
what is marasmus??
purely energy deficiency - emaciation and ketosis possible
what can elevated protein intake over long period of time result in??
increased water loss (only if kidneys aren't working properly)
bone health issues - when Ca intake is adequate, high protein diets associated with greater bone mass
Kidney Stones
Heart Disease
Cancer
(in regards to protein)
Kidney stones
Diets high in animal protein and low in fluid may
stimulate formation
Heart Disease
High protein diets often high in SFA and
cholesterol, and low in fibre
Cancer
High protein diets often low in grains, vegetables
and fruits
LIMITING AMINO ACID
If you have an AA that is in short supply and is required then you may break down body stores - if you don't have enough it is called a LIMITING AMINO ACID - it will stop protein synthesis
what is PKU??
INHERITED condition attributed to a defective gene
aspartame - makes phenyl ketones which are toxic to the brian
3 ways allergens can appear on the label
- listen in the ingredient list
- identified in parentheses
- with use of the word "contains
negative and positive nitrogen balance
negative: nitrogen intake < nitrogen ouput - tool body protein decreases
positive nitrogen balance - nitrogen intake > nitrogen output - total body protein increases
what is the % that our body turns over protein each day??
.2-.4%
what is the protein decimal we must know to calculate protein intakw
.8
what is the DRI for protein, what is special about infants, children and pregnancy
10-35%
infants and children need extra protein for growth
pregnanciy: extra protein needed for expansion of blood volume, enlargement of uterus and breasts, placenta, growth of fetus
need extra protein for breast milk
how do protein requirements change for endurance and strength athletes?
endurance: 1.2-1.4
strength: 1.2-1.7
what is protein quality
complete protein
incomplete protein
Protein quality: measure of how good the
protein in a food is at providing the essential
amino acids needed by body
n Complete protein: supply all essential amino
acids in the correct proportion
n Incomplete protein: low in one or more of the
essential am
soy products
Contains soy protein, isoflavones,
phytochemicals - which may decrease heart
disease risk
n Soy may reduce symptoms of menopause,
prevent bone loss, decrease LDL,
prevent/treat cancer?
n Soy milk, soy butter, tofu, miso, tempeh
define
vegan
semivegetarians
lacto-ovo vegetarians
lacto vegetarians
pescetarians
n Vegan: eliminates all animal products
n Semivegetarians: avoid certain types of red
meat, fish, or poultry
n lacto-ovo vegetarians: eat no animal flesh but
do eat eggs and dairy
n Lacto vegetarians: eat dairy products but no
animal flesh and eggs
n Pesc
determining if a person' body weight is healthy should include
Body Mass Index- bmi is limited when peple have disporportionately
higher ms mass for ht. BMI not desgned for less than 18y or pre/nursing women,
over 65y and certain ethnic gps ie BMI = 23 in Asians = 25 in Caucasians
Body composition
Pattern of fat dist
BMI
n Expresses the ratio of a person's weight to be
the square of their height
n BMI = weight (kg)/height2 (m2)
n BMI values below 18.5 or above 30 have
increased risks of health problems
BMI ranges
underweight
normal weight
overweight
obese
class 1,2,3
< 18.5
18.5-24.9
25-29.9
30-34.9
35-39.4
>40
limits of BMI
n Limitations of the Body Mass Index
q It is not appropriate for those who are:
n High in muscle mass
n Under 18 years old (or still growing)
n Pregnant or breast feeding
n Over 65 years of age
what is body composition made up of?
Body composition is the proportion of muscle,
bone, fat, and other tissues that make up a
person's body weight
Fat Mass: adipose tissue
Fat free mass: muscle, organs, bone, water
methods and considerations for
underwater
BODPOD
DXA
BIA
Skinfold
Involves weighing an individual both on
land and in the water = body volume and
body density, which is proportional to fatfree
mass.
- The percentage of body fat can then be
determined using standardized equations.
- Accurate, non-invasive
- Participant b
location of body fat - what are the was it circumferences that we need to be under, what does visceral fat lead to
The risk associated with visceral fat
deposition can be estimated by measuring
waist circumference.
n A waist circumference greater than 102 cm
for men and 88 cm for women is associated
with greater risk .
n A increase in visceral fat is associated with
h
the fat distribution patterns - apple and bear
Apple-shaped fat
patterning - upper body
Increased risk for chronic
diseases
Pear-shaped fat
patterning - lower body
No significant increased
risk for chronic diseases
Visceral versus
subcutaneous adipose
tissue
when does energy balance occur
Energy balance occurs when energy
consumed equals energy expenditure
where is energy stored in the body?
glycogen (liver and muscle), Glucose or free fatty acid (body fluids)
Triglycerides (adipose tissue)
protein (muscle)
energy intake
energery expenditure
calls from food
cal expended at rest and during physical activity
energy imbalances (weight gain and loss)
consume a small amount of food, expend high energy - weight loss
consume large amount of food and small amount of energy expended - weight gain
3 components of energy expenditure
BMR, TEF, energy cost of physical activity
BMR and Factors that affect BMR
energy expended to maintain basal, or resting, functions of the body
highest proportion of total energy
expenditure
Factors that affect BMR:
Amount of lean tissue
Height, age, gender, fasting
Growth (including pregnancy and lactation)
Thyroid hormone
Some
TEF, energy expended in physical activity
energy expended to process food
Energy cost of movement above basal
Affected by body size, intensity of
exercise, and how long activities are
performed
hierarchy of nutrient use
alcohol, protein, carbs, fat
estimating energy expenditure
calculate BMR
total energy expenditure = BMR x physical activity factor
whether a person gains or loses weight depends on
Energy intake vs. energy expenditure
Genetic factors
Hormones
Childhood weight
Behavioral factors
Social factors
factors that affect food intake
Body systems
Hormones, nerves, blood nutrient levels
Social influences
Peer pressure ie pressre from family to eat
Culture
Religion
Societal norms, pleasure, environmental influences, disease influences, emotional factor, metabolic influences
thrifty gene theory
Proposes that a gene (or genes) causes people to
be energetically thrifty
Proposes that people with this gene expend less
energy than other people and therefore gain
weight when food is plentiful
A "thrifty gene" has not been identified but research cont
set-point theory
Proposes that each person's weight stays within a small range (set point)
The body compensates for changes in
energy balance and keeps a person's weight at their set point Explains why dieting may not work: energy conservation contributes to rebound weigh
hormone factors for weight loss/gain
qLeptin is a hormone produced by fat cells that
causes reduced food intake, reduced weight,
decreased body fat
q Leptin is controlled by the ob gene
q Mutation of the ob gene causes reduced levels
of leptin leading to increased food intake and
reduced ene