Nutr- MT2

ch. 5, 6 & 7

red blood cells and the brain need…

carbohydrates

carbohydrates

one or more sugar units CHO

simple carbohydrates

monosaccharides and disaccharides

monosaccharides

glucose, galactose, fructose

disaccharide

maltose (glucose+glucose), sucrose (glucose+fructose), lactose (galactose+glucose)

complex carbohydrates

oligosaccharides, polysaccharides

polysaccharides

large molecules composed of chains of hundreds or even thousands of monosaccharides (glycogen, starches, fibre)

starch is stored in…

plants

glycogen is stored in…

animals

fibers CC

indigestible residues of food that comes from plants and cannot be broken down by human digestive enzyme

2 types of fibre

soluble (helps lower cholesterol) and insoluble (passes unchanged through the colon)

foods with soluble fibre

cooked beans, fruits, vegetables, nuts and seeds

foods with insoluble fibre

tubers, vegetables, whole grains

Adequate Intake for fibre

men: 39g/d women: 25g/d

digestion and absorption of carbohydrates

1. mouth- salivary amylase
2. small intestine- the disaccharides are broken down to monosaccharides by an specific enzyme to be able to be absorbed

sucrose is broken by…

sucrase

maltose is broken by…

maltase

lactose is broken by…

lactase

calcium sources

fortified cereals, sweet potato, edamame, yogurt, chia, tofu, sesame seeds

all dairy do not have the same amount of lactose

milk has more lactose than cheese

lactose intolerance

\-babies can born with/without lactase

\-older people with age the enzymes activity will diminish

if lactose goes through the GIT undigested: draws in water, explosive diarrhea, gases on the colon

other functions of carbs

\-monosaccharides: galactose is used by nerve cells to make milk during breastfeeding

\-oligosaccharides: cell membrane signaling

\-polysaccharides: cushioning and lubrication in joints

glucose homeostasis

2 pathways:


1. after a meal, your blood glucose levels will increase so your pancreas will release insulin to convert glucose into glycogen (stored in the liver and muscles) and fat (when stores are full) to reach a normal range of blood glucose
2. hours later after a meal, your blood glucose levels will drop so your pancreas will release glucagon to be synthesized to glucose to reach a normal range of blood glucose

diabetes mellitus

disease characterized by high blood glucose

type 1

elevated blood glucose, absolute insulin deficiency cause by an autoimmune destruction of insulin-secreting cells in the pancreas

type 2

insulin resistance, relative insulin deficiency

gestational

observed during pregnancy and increases the risk of diabetes type 2 later in life

concerns of diabetes

high blood sugars cause long term problems such as fatigue, thirst which causes kidney overwork, vision issues, peripheral nervous system damage, hunger and weight loss, infection and slow wound healing

low blood sugars cause immediate problems such as unconsciousness, hunger, shakiness, irritability

RDA for carbs

130g/d

AMDR for carbs

45-65%

chose carbs from…

whole grains, vegetables, fruit and proteins and limit highly processed foods, sugary foods and drinks

based on Canada’s Food Guide our plate should have what portion of carbs

1/4 of your plate should be carbs

whole grain

contain the whole kernel, including the germ, the bran, the endosperm

refined grains

food processed to remove course parts

whole grain parts

endosperm: largest part of the kernel (protein and some vitamins and minerals)

bran: outermost layer (fiber, vitamins and minerals)

germ: located at the base of the kernel (vitamin E and oils)

natural sugars

found in whole fruits and vegetables

added sugars

monosaccharides and disaccharides added by the manufacturer

based on WHO how much sugar should we consume

less than 10% of total energy intake from free sugars

based on Canada’s food guide we should consume ____ sugar

less than 25% of total energy intake

based on food labels we should consume____ sugar

less than 15% of DV

sources of dietary fats

\-animal sources: meat, cheese, diary

\-plant sources: vegetable oils, nuts, avocados

\-”hidden” fats: french fries, pizza, pasta dishes, baked goods, salad dressings

role of fats in food

\-provide texture, flavor, aroma

\-help absorb fat-soluble vitamins (A,D,E,K)

\-1g of fat= 9kcal

\-AMDR of fat= 20-35%

\-affects health + and -

\-consume the minimum amount of cholesterol, saturated fats and trans fats

types of fats

lipids: group of organic molecules, insoluble in water

saturated fats

carbon atoms bonded to as many hydrogen atoms as possible with no carbon to carbon double bonds

foods with saturated fats

\-medium-chain saturated fats: animal foods (meat and dairy) and plant oils

unsaturated fats

contain one or more carbon to carbon double bonds

food with unsaturated fats

\-monounsaturated fatty acids: lean meats, olive oil, avocado, nuts, and lower LDL cholesterol

\-polyunsaturated fatty acids: plant sources, plant oils

saturated fats vs. unsaturated fats

saturated fats are solid at room temperature - unsaturated fats are liquid are room temperature

saturated fats are in animal sources and tropical plants - unsaturated fats are in vegetable origin

saturated fats are associated with disease - unsaturated fats are associated with lower risk of disease

essential fatty acids

those that cannot be produced in the body and needs to be obtained from the diet such as Omega 3 and Omega 6

sources of omega 3

fish, walnuts, canola oil, ground flaxseed, hemp and fortified foods

sources of omega 6

trans fats

processed fats by hydrogenation which makes food more saturated causing a longer shelf life

foods with trans fats

fried foods, margarine, baked goods, packages sweet and salty snacks

choose products with ___ saturated fats

10% or lower

phospholipid

part of the cell membrane that allows water and fat to mix

sterols (cholesterol)

used to make bile for digestion, deposited in the artery walls→plaque buildup and heart disease, structure of cell membranes, made in vitamin D, hormones necessary reproduction (estrogen and testosterone)

fat digestion

1. a small amount of lipid digestion occurs in the stomach due to gastric lipase
2. bile is released in the small intestine and aids in the digestion and absorption of lipids
3. the pancreatic lipase breaks down triglycerides, fatty acids, and glycerol in the small intestine
4. in the small intestine the products of fat digestion and bile acids from a micelle move toward the microvilli to diffuse the lipids into the mucosal cells
5. inside the mucosal cells, the fatty acids and monoglycerides are resembled triglycerides and incorporated into chylomicrons which enter the lymph vessel and later enter to the blood

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emulsification of fat

bile has affinity for fats and for water so it brings them together as small droplets of emulsified fat. the bile “encapsulates” the fat with the enzyme

lipoproteins (VLDL, LDL, HDL)

core of triglycerides and cholesterol surrounded by a shell of protein, phospholipids and cholesterol

function of lipoproteins

\-VLDL particles are made in the liver and released to the blood. They have a similar function to chylomicrons that transport triglycerides which are broken down by lipoprotein lipase

\-LDL particles deliver cholesterol to cells. high levels of LDL in blood increase risk of heart disease

\-HDL particles transport cholesterol from cells to the liver. HDL is “good” cholesterol because it lowers cholesterol content in blood

\-the liver uses cholesterol to make bile

LDL vs. HDL

\-LDL particles transport cholesterol from the liver to body cells. try to decrease your blood levels of LDL

\-HDL particles transport cholesterol from body cells to the liver so they can be excreted. try to increase your blood levels of HDL

Lipoproteins are…

blood transport molecules

we do not eat LDL and HDL

they are made by the body by packaging cholesterol and triglycerides into lipoprotein particles for transport in blood

food fat → body fats

\-saturated fats INCREASE LDLs

\-monounsaturated fats lower LDLs and maintain HDL

\-polyunsaturated fats lowers LDL and ELEVATE HDLs

\-trans fats INCREASE LDLs and lower HDLs

functions of fat in the body

food flavor and texture, satiation, energy, provides essential fatty acids, provides fat soluble vitamins, cell membranes, protection

causes malconsumption of lipids

\-the amount and type of fat can affect your health

\-too little dietary fats affect growth, sight and impair physiological functions

\-too much dietary fats and saturated fats contribute to cardiovascular diseases and cancer

heart disease

\-atherosclerosis: buildup of fatty material in the artery walls

\-atherosclerotic plaques: narrow blood vessels and limit blood flow → less oxygen and fewer nutrients are delivered to tissues, blood vessel injury, inflamation and LDL cholesterol oxidization

functions of proteins

\-workhorses

\-structure of body

\-immune system

\-digestion

\-hair and nail growth

\-enzymes, fluid balance and acid-base balance

sources of proteins

animal, plant, grain, nuts and legumes

proteins are made up…

carbon, hydrogen, amino group, acid group and unique side chain

amino acids always have an amino group of….

nitrogen

there are __ different side chains

20

building block of proteins

amino acids

essential amino acids

9 essential amino acids that cannot be made in the body so we must consume foods with them

non-essential amino acids

11 non-essential amino acids that can be synthesized in the body

conditionally essential amino acids

body can produce them but at times of significant stress the body can’t make enough to meet the needs. Some non-essential amino acids become “essential” under certain circumstances (arginine, cysteine, glutamine, glycine, proline, tyrosine)

branched chain amino acids (BCAA)

they are directly converted to muscles without having to be converted to glucose (dairy, soy, whey and wheat protein)

protein structure

\-peptide bonds: connect amino acids to form proteins

\-polypeptides: a chain of amino acids linked to form tangled coils

\-proteins: made of 1 or + polypeptide chains folded into a specific 3 dimensional structure

the shape of the protein…

determines its function, if it is changed the function changes

protein digestion

eat→chew→swallow→stomach


1. stomach high acidic environment denatures protein and activates pepsin to break polypeptides into smaller chains
2. small intestine the pancreas releases enzymes (trypsin and chymotrypsin) to break proteins into single amino acids, dipeptides and tripeptides so they can be absorbed into the blood vessels

post-absorption of proteins

single amino acids join at the amino pool circulating in blood. there is no storage of amino acids, extra amino acids are converted to fatty acids or made into non-protein

synthesizing non-essential proteins

the needed amino acid is pulled from the pool but if the pool runs out of an amino acid the process can be stopped but if the limited amino acid is non-essential it can be made in the body by transamination by transferring the amino group to a carbon containing molecule

complete protein

a protein will all the essential amino acids

incomplete protein

missing 1 or + of the essential amino acids

protein quality

determined by amino acid content and digestibility

sources of complete proteins

\-animal sources: meat, fish, eggs, milk and dairy products

\-plant based sources: quinoa, buckwheat, hemp seed, soy

incomplete protein food sources

nuts, grains, legumes, vegetables

complementary proteins

mixing the complementary items gives you a complete protein

functions of proteins in the body

structural and working proteins

structural proteins

muscle, connective tissue, vital organs, hair, skin, nails, growth and maintenance

working proteins

hormones, enzymes, DNA and RNA, transport proteins, plasma, antibodies, energy and glucose production, fluid balance, acid base balance

protein requirements

AMDR: 10-35%

RDA: 0.8-2.0 g/kg

times of growth: childhood and pregnancy +25g/d

weight loss, acute injury, blood sugar balance, elite athletes, elderly and chronic illness, times of stress

nitrogen balance

nitrogen balance= intake-loss

positive nitrogen balance= intake> loss

negative nitrogen balance= intake< loss

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intake=diet

loss=urine, sweat, hair, nails, skin

extra protein=extra muscles?

false

omnivore

eats meat and plant foods

pesco pollo vegetarian/semivegetarian

eats chicken and fish

lacto-ovo vegetarian

eats eggs and dairy products

pescetarian

consumes fish

vegan

avoids all animal products

fruitarian

only eats fruit