HUNT141 Flashcards
Nutrition
Intake of food in relation to the body’s dietary needs
Nutrients
Molecules found in foods needed by the body for energy, growth, development and reproduction
Non Communicable Disease
Conditions resulting in long-term health consequences and often create a need for long-term treatment and care
Modifiable Risk Factor
Effect of risk factor can be changed by stopping it. Diet
Double burden of malnutrition
coexistence of undernutrition and obesity within individuals, households and populations.
Mortality
Death
Food security
Regularly have access to food of nutritious and appropriate quality/quantity
- Accessible and reliable
Food Sovereignty
How food is grown, how, who can access. Right of people to healthy and culturally appropriate food produced through ecologically sound and sustainable methods.
- Right of a community to define own diet and shape own food system
Atwater factors
17KJ/g - protein & carbohydrate
37KJ/g - fat
29KJ/g - alcohol
AMDR of protein, fat, carbohydrate
PROTEIN- 15-25
FAT- 20-35
CARBOHYDRATE- 45-65
Formula for energy in food and % energy
g macronutrient x Atwater (÷ total energy for %)
NRV
Nutrient reference values, amount of nutrient needed/required to be healthy based on age and sex
EER
Estimated energy requirement, Energy needed to maintain weight. BMR +PAL
AMDR
Acceptable macronutrient distribution range
Protein -15-25
Fat- 20-35
CHO - 45-65
EAR
Estimated average requirement
EAR + 2SD = RDI
RDI
Recommended dietary intake
EAR + 2 SD
AI
Adequate intake
- set when there is not enough information to ear out the EAR
Mouth
32 teeth
- Amylase enzyme in the saliva breaks down CHO
- Tongue mixes in the saliva and pushes food to back of throat
Oesophagus
Saliva moisten/lubricates the food going down.
Logitudinal and horizontal muscles
Peristalsis - moves food down through system
Sphincter - controls movement between areas
Choking
Food gets stuck in the larynx inhibiting breathing therefore why pushing in lungs for air to push out stuck food
Stomach
Digests protein
Digestion:
Chemical - HCL and Pepsin proteins
Physical - Contractions
Gastrin hormone detects chyme and sends for HCL and pepsin
HCL acidic nature, denatures amylase enzyme and protects from bacteria, mucosal lining protects the stomach
Heart burn
Sphincter between stomach and oesophagus releases some content back up. Acidic nature irritates the oesophagus and since close to heart gives sensation of heart burn
Small intestine
PHYLORIC SPHINCTER
Key in digestion and absorption molecules.
Presence chyme - Hormone secretin interacts pancreas for PANCREATIC ENZYMES
Fat/protein presence - Cholecystokinin hormone interacts gall bladder, pancreas for Bile, Pancreatic juices and intestinal juice.
Bariatric surgery
Surgery on stomach size for weight loss
Large intestine
ILEOCECAL VALVE
1.5m long
reabsorption of water and minerals. Ferments the undigested foods.
Absorption nutrients
Microvilli/villi, wrinkles with intestinal limen cells that break into small enough molecules to fit through
- Nutrients cross microvilli boarder into cells, blood or lymph.
Transport from gut
Absorbed nutrients through microvilli travel to liver (major metabolic organ) via the hepatic portal vein
Large fats and fat soluble vitamins too big to enter the hepatic portal vein so straight into blood
Coeliac disease
Allergy to gluten flattens the microvilli affecting the absorption of nutrients and causing deficiencies.
Monosaccharides
Glucose - essential energy source
Galactose - Dairy but rarely occurs as single sugar
Fructose - sweetest (fruits)
Disaccharides
Sucrose - glu + fru - refined from sugar cane (fructose still sweeter sometimes)
lactose - glu + gal - milk products
Maltose - glu + glu - germination seeds/fermentation
Starch
Plant storage of glucose. Grains, legumes.
Amylose = long strand
Amelopectin = Branched
Glucose
Essential energy source
Fructose
Sweetest monosaccharide and found in fruits
Galactose
Not often found as single sugar (dairy)
Maltose
Glu + Glu - Germination of seeds/fermentation
Sucrose
Glu + Fru - refined from sugar cane
Lactose
Gal + Glu - Milk products
Glycogen
Main storage form of glucose in humans. Highly branched
Dietary fibre
Edible part of plants
- Resistant to digestion/absorbtion, partial or full fermentation in the large intestines
- Promotes laxation, regulation BGL, lowers cholesterol
Non-starch polysaccharides
Resistant to small intestine enzymes (cannot get past the barrier to digest)
Intrinsic- Physically accessible
Extrinsic- Travel/chewing time
Free sugars
Monosaccharides and disaccharides added to food by manufacturer, cook or self AND naturally occurring in fruits and honey etc
Intrinsic sugars
Naturally occur in fruits and unprocessed foods
Added sugars
Generally extracted from sugar cane and added to foods
What % energy free & added sugars?
10%
- Prevent obesity for energy consumption
- Prevent dental caries
Reducing intake
- Sugar taxing
- Labelling
- Modify taste
- non-nutritive sweetners
Carbohydrate digestion
Amylase in mouth and from pancreas breaks the CHO and starches into sugars (monosaccharides)
- Amylase from pancreatic juices breaks polysaccharides into monosaccharides.
Carbohydrate metabolism
Glucose, galactose and fructose travel to liver through hepatic portal vein. Liver converts all sugars into glucose for:
- Energy (brain)
- glycogen stores
- met energy requirements, turned into FAT
Lactose intolerance
Lactase enzyme breaks lactose down to monosaccharides (glucose + galactose). If doesn’t persist, not broken down in small intestines and goes into care intestines which then gets broken by bacteria making CO2 and H2O causing gas and diarrhoea.
Glycemic index
Rating system for carbohydrates and how quick they affect blood sugar after eating on their own.
Low GI = slow breakdown
ISSUES
1. Individuals are different
2. Varied serving sizes
3. Combining foods will change the GI
Glycemic load
Accurate picture of real life foods impact on blood glucose levels
Glycemic load
Accurate picture of real life foods impact on blood glucose levels
GL = GI x CHO / 100
Wheat
Bran, Endosperm, Germ
Milling loses germ and bran = loss nutrients
wheat is good source of proteins, carbs, dietary fibre
- Wholemeal has more protein
Colon Cancer
1/18 NZ develops cancer. Lower risk by consuming more dietary fibre.
Risk factors:
- Age - Genetics - Smoking & obesity - Alcohol
Protein
Nitrogenous organic compound composed of amino acids.
Amino acids
Building block of protein
Complementary proteins
Proteins eaten over a day ~30g a meal.
Protein containing all the essential amino acids
Indispensable amino acids
9 essential amino acids, need from the diet, cannot be made
Dispensable amino acids
5 amino acids the body can make by changing and adding to existing amino group R groups.
Limiting amino acids
Protein synthesis limited by an essential amino acid
protein function
Contractile functions, transportation, immune response, structures
Primary proteins
Chain of amino acids
Secondary proteins
Weak electrical attraction between polypeptides, strength and ridgity
Tertiary proteins
twist and fold of polypeptides, gets more complicated. Intricate shape.
Quanterary Proteins
Fold up and join; interactions between multiple polypeptides (Haemoglobin)
Primary source of protein
Bread, meat and fish
Protein quality
Based on content of essential amino acids in food and the digestibility
- PDCAAS - Protein digestibility
- PER - Protein efficiency ratio
- DIAAS - Digestibility of indispensable amino acid score
Protein Digestion
Physical (chewing) and chemical (peristalsis) digestion.
Stomach HCL and pepsin enzymes unravel proteins exposing polypeptide chain
- Peptides broken into amino acids, transported to liver via hepatic portal vein.
Amino acid pool - fates of amino acids
- Form dispensable amino acids by shifting around
- Oxidised for energy
- Make new proteins
- Make other compounds
Food hypersensitivity
Includes food aversion, intolerance and allergy
Food aversion
Psychological response, can be overcome.
Food intolerance
10-15% population. reproducible/abnormal response to food
Food allergy
A group of disorders characterised by abnormal reproducible reaction to specific food proteins.
1. IGE mediated reaction
Rapid onset, skin, respiratory and GI tract, involves the IGE antibodies
2. non-IGE mediated response
Hours-day response, not antibody but other unknown mechanism response
Vegetarian types and % NZ
5% NZ is vegetarian
lacto-ovo-vegetarian - doesn’t eat meat but does everything else
Lacto-vegetarian - doesn’t eat meat or eggs but everything else
Vegan and % NZ
1% NZ
Does not consume any animal products and may limit the use of other animal products
Benefits and concerns with vegetarian diets
BENEFITS
- Obesity, diabetes and other NCDs
CONCERNS
- B12, iron, zinc, bone mineral density, substitutes not as nutritional
Bray et. al study on protein diets and over eating
Little protein decrease lean body mass
high protein increase body weight and lean body mass
Lipid
Organic fatty acid compounds insoluble in water but solute in organic solvents
Triglycerides
90% fat in the diet. energy storage. Ester bond of glycerol and 3 fatty acids
fatty acid
Chain of carbon molecules with a methyl (omega) group and a carboxl group. Double bonds affect the melting point. Hydrophobic.
Saturated fatty acids
Saturated with hydrogens. Highest melting point, with no double bonds
monounsaturated fatty acids
One double bond, 6C from the methyl group
Polyunsaturated fatty acids
Low melting point with methylene group separating the double bonds. Body cannot insert double bonds before 6 carbons.
Trans fatty acids
Act as a saturated fat with no double bond. Double bonds increase the melting point.
Essential fatty acids
- deficiencies also
Must be from diet as humans cannot insert double bonds before 6 carbon. 1-3% total energy, Deficiency:
- Growth, reproduction, visual, skin, kidney/liver problems
Phospholipids
Glycerol backbone + hydrophobic fatty acid backbone with hydrophilic phosphate group
Fat AMDR
20-35% total energy
% energy from saturated fats
13%
Lipid digestion
Body heat, chewing and peristalsis
- liquify forming globules.
- LINGUAl LIPASE and BILE ACIDS emulsify fat
Lipase from pancreatic and intestinal juices breaks fat into:
- monoglyceride
- glycerol
- fatty acids
Lipid absorption
Short chain fatty acids absorbed into hepatic portal vein
CHYLOMICRONS go into lymph system, not directly to liver but MUSCLES
Lipoproteins
Transport hydrophobic lipid molecules in water, blood or ECF
Chylomicron
Carry lipid to most body cells
HDL
High density lipids, picks up cholesterol and transports to liver for excretion
LDL
Delivers lipids to body or back to liver
VLDL
forms smaller LDL and delivers lipids to body cells
Albumin
Transports free fatty acids from adipose to peripheral tissues.
CVD
Cardiovascular disease, disorders of heart and blood vessels.
Risks:
- Weight, blood pressure, glucose and lipids
35% women deaths
Modifiable risks vs non modifiable
Modifiable risks include diet and exercise that can be altered to reduce risk.
Non-modifiable risks cannot be changed to reduce risks. These include age and gender.
Saturated fats effect on LDL
Saturated fats increase LDL levels therefore increasing risk of heart diseases
Trans fats effect
Negatively affects blood lipid levels increasing the risk heart disease more than saturated fats
Ketogenic diet
Build muscle, reduce intake of carbohydrates putting body into ketosis, liver converts fat into ketone bodies as an alternative energy source.
Alcohol absorption
20% absorbed in stomach, 80% small intestines.
Alcohol metabolism
Majority in the liver, small amount in the stomach, excreted in urine, breath and breastmilk
- ADH - Alcohol dehydrogenase
- MEOS - microsomal ethanol-oxidisning system
- CATALASE - hydrogen peroxide presence
ADH
Alcohol dehydrogenase
- Rate limiting, 1 SD an hour
- Major pathway for most
- Brain, liver, pancreas, stomach
MEOS
Microsomal ethanol-oxiding system
- Active in long term drinkers
CATALASE
Presence of hydrogen peroxide
- Converts ethanol into acetaldehyde
- less than 2% broken this pathway
Factors affecting alcohol metabolism
- Quantity - ADH is rate limiting to 5-10g/hr
- Gender - Females have less body water, smaller livers, higher absorption in stomach and less ADH in stomach
- Size - bigger size breaks alcohol better
- Genetics - variant of ADH
Consuming too much alcohol affects
- Acetaldehyde, short lived but toxic effects to liver and brain. Long term cirrhosis liver and cancers
- Elevated NADH:NAD+ ratio, NAD unavailable for alternative pathways. increases lipid synthesis. H+ affects acid/base ratio.
- induced metabolic tolerance - MEOS produces toxic metabolites
REE
Resting energy expenditure
Determinants:
weight, height, age, fat free mass, fat mass, gender, hormones, SNS
DEE
Diet induced energy expenditure (DIT)
Determinants:
- amount food, composition, hormones
10% energy, varies with diet
- Protein>CHO>Fat
AIEE or PAL
Activity induced energy expenditure // Physical activity level
Determinants:
- Intensity, Duration, Weight, Genetics
Obesity and how to measure
Abnormal, excessive fat accumulation presenting a health risk
MEASURE:
- Distribution of fat, narrowest part of waist. women = pear. Man = Apple.
- Amount of excess fat stores, BMI
BMI and obesity
Weight÷height^2
- Healthy, 18.5-25
- Overweight ≥ 25
- Obese ≥ 30
6-7/10 obese
Obesity prevention
Environment
- Government goals/policies
- Labelling in food industry
- Health professionals
Individual
- Education and knowledge
- Networks and support
Water
Simple idol that is the largest single component of the human body. Man: 60% Woman: 50%
- Input and output: 1450-2800ml
BENEFITS:
- Weight control/loss
- wash toxins out that could cause bladder cancer
- Kidney disease
Three different dehydrations
Mild - Headache, thirsty, unwell (2-5% body weight)
Moderate - Lethargic, rapid pulse, dry mouth and eyes, sunken fontanelle (6-10% bodyweight)
Severe - Drowsy, no urine, child death (≥10% bodyweight)
Mild dehydration and treatment
2-5% bodyweight
- Headache, thirsty
- Drink water and eat
Moderate dehydration and treatment
6-10% bodyweight
- Lethargic, rapid pulse, dry mouth/eyes, sunken fontanelle
- Medical approach, IV
Severe dehydration and treatment
≥10% bodyweight
- Death in children, drowsy, no urine and feeble pulse
- ORS and Zinc
- IV
ORS
Oral Rehydration Salts
- replace lost electrolytes
- Transport mechanism in gut lumen brings glucose across into intestinal cell and water follow along in a 1:1 ratio.
Insulin resistance
Organs stop responding to insulin, more needing to be produced but BGL remains high for longer damaging blood vessels
Polyphagia
increase in appetite due to glucose travelling to kidney causing osmotic diuresis and polyuria
Polydipsia
increase in urine due to glucose travelling to kidney causing osmotic diuresis and polyuria
what % NZ has type 2 diabetes
5-7%
Long term diabetes concequences
Blindness, Amputation, CVD (30-50% deaths), Kidney failure
Lifestyle changes to reduce diabetes risk
- Reduce energy intake
- Exercise more often
- Increase intake of fibre
- Reduce saturated and total fat intake
Bran
Fibre-filled outer layer of grain. B vitamins and minerals
Endosperm
Starchy CHO middle layer, proteins and vitamins
Germ
Nutrient packed core, B/E vitamins, phytochemical’s and healthy fats
Sodium dietary sources and %
10% inherent - food itself
15% discretionary - added salt at own decoration
75% processing - food manufacturers
Sodium absorbtion/regulation
Well absorbed. Not regulated
Sodium Excretion
> 90% excreted in urine
Sweat
Sodium hypertension
Higher than normal blood pressure, can damage blood vessels increasing CVD risk
DASH 1
Three groups, same sodium intake.
Limitation:
- combination of other beneficial macronutrients had a beneficial effect
DASH 2
Two diet groups, three levels of sodium
- control diet
- DASH diet (high fruit and veg)
Drop BP as NA dropped
Potassium sources and functions
Fruits and Vegetables
- Main cation inside cells
- fluid and electrolyte balance
- facilitates relations (nerves, muscles)
Hypertension of K+
inverse effect on CVD, more K+ decrease risk.
Calcium food sources
Milk
Bread
non-alcoholic drinks
cheese
Calcium absorption
25-30% absorption in diet.
Pregnancy and diet can increase absorption.
Calcium Inhibitors and Promotors
INHIBITORS - Ca binds to negative groups then becomes insoluble and excreted
- oxalate
- Phosphorus
- Phytate
PROMOTORS
- protein and amino acids
- lactose
- acidic gut
Calcium regulation
47% bound to proteins, 47% free or ionised, 6% bound to anions
Calcitonin - Bring Ca down
- inhibits vit D activation
- Prevents Ca reabsorption in kidneys
- Limits intestinal absorbtion
- Inhibits osteoclast cells breaking bones
Parathyroid hormone - Increase Ca
- Activates vit D
- Reabsorption activated in kidneys
- Vit D enhances intestinal absorbtion
- stimulates osteoclast to break bone releasing Ca into blood
Bioavailability
Proportion of nutrients consumed that is absorbed and utilised thus available to the body.
Ca and bone (Trabecular and cortical)
Cortical
- 80% bone mass, compact, slow turnover
Trabecular
- 20% bone mass, sponge, day to day withdrawls
Osteoporosis suffering statistics for men and women
Over 50 years age
Men 1/5
Women 1/3
Sources of iron
meat, chicken, fish, legumes, fortified foods
iron bioavailability and enhancers/inhibitors
Absorption is host related - pregnancy, low status
Haem form ~25-30% absorption - fleshy foods
Non-haem ~5-15% absorption - Breads
ENHANCERS - Vitamin C, meat, poultry
INHIBITORS - Tannins and phytate
Phytate
Water soluble.
Where geminating plants store phosphate, generally inhibitor for absorbing iron, zinc
Rid by refining grans, fermenting (yeast) or soak/canning
Non-haem absorption
5-15%, breads
Haem absorption
25-30%, fleshy foods
Iron main function
Haemoglobin is 67% body iron and transports oxygen in red blood cells
Charges Fe molecule allows the binding of O2
Iron deficiency anemia
- Growth and behavioural disturbances
- Decrease cognitive function
- Fatigue as less haemoglobin carrying O2 in body
- spoon shaped nails
Iron toxicity
-Excessive supplement consumption
- 1/2 children under 6 die of iron overdose (supps)
Hereditory Haemochromatosis
Higher iron status, women absorb more
- associated with diabetes and the iron solute (iron builds up in joints and can’t form fists)
- yellowing
Zinc food sources
meat, dairy, legumes and oysters
Zinc bioavailability - enhancers and inhibitors
Pregnancy increases absorption aswell as low status
ENHANCERS
- Fish foods, dairy, eggs
INHIBITORS
- Non-haem iron, Ca and Phytate
Functions of zinc
Enzymes need it to function
Biosynthesis
- Growth
- Reproduction
- Appetite
- Immune function
- Vit A metabolism
Zinc deficiency (1960 Middle East)
Dwarfism, no secondary sexual development
- no yeast so high phytate
- low animal foods intake
- Geophagia - eat earth
Zinc toxicity
- metallic taste
- Nausea
- gastric distress
- fatal
Selenium enzyme
glutathione peroxdases
-prevents oxidative damage to phospholipids
- Derodinase for thyroid hormone
Selenium sources
Plant leaves, grains, bread
- 2 Brazil nuts
Selenium metabolism
80% absorbed, no regulation
- organic is active transport
- 50-60% excreted in the urine
Keshans disease
selenium intake, cardiomyopathy child and pregnant
Selenium toxicity
rare from diet
- paleness, irritable, indigestion, giddiness. lassitude
Flouride
100% absorbed
Inhibits growth bacteria and demineralisation. Enhances remineralisation
TOO MUCH = aestetic fluorosis (white spots)
Aestetoc fluorosis
Too much fluoride causes white spots on the teeth
iodine functions
-Thyroid hormones
-Maintain metabolic rate
-Growth and development
Iodine dietary sources
Seafood and iodised salt
moderate - eggs, milk, fortified bread
poor - fruit and veg
Iodine deficiency specutrum
Mild - Goitre
Moderate - impaired mental and motor abilities
Severe - Hypothyroidism, cretinism
Cretinism
Pregnant and iron deficient
- short, characteristic squint, mentally impaired
NZ reemerge of iodine deficiency
- Himalayan salt phase
- Less salt as correlation to CVD
- Eating more processed food
- Iodophors were swapped for detergents
Iodine increasing intake strategies
Dietary diversification
Supplementation
Fortification
Thyrotoxicosis
Toxic amounts of iodine
- Excess thyroid hormone
- Hyperactivivity, increased BMR
- Molecules unresponsive to normal feedback mechanisms
Ultra-processed foods
Extent and purpose of food processing placing foodstuffs into 4 groups
one - fresh and minimal process (coffee, flour, milk)
two -culinary ingredients (oil,butter,sugar)
three - addition one and two for processed foods (cheese,tomato paste)
four - Ultra processed food (snack foods, carbonated drinks)
WHO and processed foods
SHAKE -want less tan 5g a day
Surveilence, Harness industry, Adopt labelling, Knowledge, Environment
B1
Thiamin
- nerve processes
- energy metabolism
B2
Riboflavin
- Energy metabolism
- milk and fortified breakfast
DEFICIENCY
- Inflamed eyes, light sensitivity
- Sore throat, cracked/red mouth
- Purple tongue
B3
Niacin
- Energy metabolism
- Pellagra: 4D’s
- Sources, poultry and bread
4 D’s of pellagra
Dermatitis, Death, Dementia, Diarrhoea
B5
Pantothenic acid
- RBC synthesis, neutron activity, antibody production
- Sources: organ, mushrooms, avo, broccoli
B6
Pyridoxine
- Energy metabolism
- Sources: Fruit and vegetable
B7
Biotin
- CoA assists in glycogen synthesis, fat synthesis and amino acid metabolism
- widespread foods can be synthesised by intestinal bacteria
B9
Folate
- Supplement during pregnancy to avoid Neural Tubal Defects
B12
Cobalamin
- 3-5 years supply
- meats and milks
Water soluble vitamins
B & C Vitamins
- directly into blood
- easily excreted
- need every few days as is readily excreted
Fat-soluble vitamins
A, D, E, K vitamins
- Blood via lymph
- requires a protein carrier
- stored in adipose tissue
- need every week or month
Vitamin C deficiency and type of nutrient
Scurvy
- Skin and joint haemorrhages
- sudden death
Antioxidant nutrient
- regenerates vit E and protects lipids
Vit C toxicity
Diarrhoea, Rebound scurvy, stomach inflammation, red eye
Vitamin A functions
Vison:
- Rod cells - low light
- Cone cells - high light & colour
- Epithelial cell health - retinoid acid moistens
- Reproduction
- Growth
- Epithelial cells/skin - protein synthesis/cell differentiation
- Immunity - open sores, disease get in
Vitamin A food sources and absorption
Retinoids - Liver, milk, eggs
carotenoids - Dark green vegetables, yellow/orange
Integrated into chylomicrons and transported lymph and stored in liver fat
Vitamin A deficiency and toxicity
DEFICIENCY
- Bitot spot, dry eyes, night blindness, reversible
- Keratinisation, change in epithelial cells, rough/dry skin
- Measles risk more severe
TOXICITY
- Birth defects
- Acute death
- Discoloured skin
Vitamin K functions and 3 types
K1 - dietary form plants, electron acceptor
K2 - Intestinal bacteria
K3 - Proviatmin, synthetic product
- Blood clotting
- Bone metabolism
- Inflammation
- Prevents oxidative brain damage
- Sphingolipid synthesis
Vitamin K food sources
Leafy green vegetables
Some cereals and dairy products’50% from gut bacteria
Vitamin E
Powerful antioxidant.
Stabilises membranes
Protects plasma lipoproteins from oxidative damage
SOURCES - destroyed my heat and oxygen
- Polyunsaturated plant oils
- Greens, wholegrain, liver, nuts
Four main greenhouse gasses
1/4 from food
- CO2
- Methane
- Nitrous oxide
- F gasses
What % GHG from farms
80%, air travel also highly impacts
What proportion of food is wasted?
1/3
