HPC1000 - Introduction to Nutrition (Unit Summary) PDF

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Summary

Everything you need to pass the unit in one document. Good luck!...

Description

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What is AGTHE (Australian guide to healthy eating)? Visual representation of a guide to healthy eating.

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What is a Standard serve? Standardised amount according to the AGTHE and other scientific sources

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Define a serving size Amount recommended by the manufacturer (Not standardised)

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Define a portion The amount you choose to eat at a given time

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Name the 5 core food groups? 1. Vegetables/legumes & beans 2. Fruits 3. Grains (cereals) 4. Lean meat & poultry, fish, eggs and/or legumes & beans 5. Dairy/alternatives Standard serve: Vegetables (g & kJ) + recommended serve: Adult (M+F)? 1. Male: 6 Women: 5 2. 75g or 100-350kJ 3. Increases with age o Standard serve: Fruit (g + kJ) + recommended serve: Adult (M+F)? 1. 2 serves a day for adults 2. 150g or 350kJ o Standard serve: Grains kJ + recommended serve: Adult (M+F)? 1. 6 serves for adults 2. 500 kJ 3. Decreases with age o Standard serve: Lean meats kJ + recommended serve: Adult (M+f)? 1. 3 serve for men, 2 ½ for women 2. Standard serve 500-600kJ or: 550kJ **** o What vitamin can only be found in animal product? Vitamin B12 Standard serve: Dairy/alternatives kJ + recommended serve for adult (m+f)? 1. Standard serve 2 ½ for adults 2. Increases with age 3. Standard serve: 500-600kJ or: 550kJ o What does it take for alternatives to be classified as Dairy group? o

contain at least 100mg of calcium per 100ml.

What is discretionary food? 1. Not essential or necessary o What does it take to be classified as discretionary food? o

high in: Salts, sugars, fats and alcohol o

What is the ADGs (Australian Dietary Guidelines)?

Evidence-based advice on eating for health and well-being. o

ADG Guideline 1:

To achieve and maintain a healthy weight, be physically active and choose amounts of nutritious food and drinks to meet your energy needs o

ADG Guideline 2:

Enjoy a wide variety of nutritious foods from the five core food groups every day o

ADG Guideline 3:

Limit intake of foods containing saturated fat, added salt, added sugars and alcohol o

ADG Guideline 4:

Encourage, support and promote breastfeeding o

ADG Guideline 5:

Care for your food; prepare and store it safely o

List the Diet planning principles

Adequacy: diet that provides energy and enough of ALL nutrients to meet the needs of healthy people. Balance: consuming enough, but not too much of each type of food Energy/kJ control: essential to maintain or manipulate body weight. Sustaining metabolic and physical activities. Nutrient density: Select food that provide the MOST nutrients for the least kJs/energy. E.g. subbing for low fat milk instead of full cream. Low-fat milk provides the same nutrient components but with less kJs Moderation: The practice of ‘occasionally’ but not often. Ice-cream is fine, but not after every meal. Variety: Variety improves nutrient adequacy, and alternating food choices reduce risk of ingesting contaminants in high concentrations (Mercury in fish)

Define BMI 1. Body Mass Index 2. An approximate measure of your best weight for health. o How do you calculate BMI? o

Weight (Kg)/Height(m^2) o

List the limitations associated with BMI

Under/Overestimates these factors; muscle, ethnicity, height and disabilities o

what is the range of BMI considered to be 'Healthy'

5 – 24.9 o

what is the range of BMI considered to be 'Underweight'

below 18.5 o

what is the range of BMI considered to be 'Overweight'

above 24.9 o

what is the range of BMI considered to be 'Obese'

30 and above o

Define Nutrient

****compounds in foods essential to life and health, providing energy, building blocks for repair and growth, and substances necessary to regulate chemical processes o

List the 6 essential classes of nutrients

Protein: meat, diary, legumes, nuts, seafood and eggs Carbohydrates: pasta, rice, cereals, breads, potatoes, milk, fruit, sugar Lipids (fats): oils, butter, margarine, nuts, seeds, avocados, olives, meat and seafood Vitamins: B & C group (Water soluble) A, D, E & K (fat soluble) Minerals: sodium, calcium, iron, iodine, magnesium Water: Beverage, and are the main component of many foods (fruit and vegetables) o

Carbon

What makes a nutrient organic?

o

What is an inorganic nutrient?

does not contain carbon o

What is energy-yielding nutrient? and List them

Contains energy or kJ Carbohydrate, protein, lipids o

List the Macronutrient that contains 17kJ/g?

Carbohydrate, Protein o

What Macronutrient contain 37kJ/g?

Lipids/fats o

How many kJ does alcohol contain per gram?

29 kJ/g o

Define NRVs

Nutrient reference values set of recommendations for nutritional intake; amount and type of nutrients differentiate between gender and age o

Define EAR

Estimated Average Requirement average nutrient intake requirement sufficient for 50% of the population o

RDI

(Recommended Dietary Intake: average daily nutrient intake requirement that is sufficient for 98% of the population o

AI

(Adequate Intake): average daily nutrient intake based on observed or experimentally- determined approximations or estimates of nutrient intake by a group on apparently healthy people that are assumed to be adequate (used when an EAR cannot be determined. o

UL

(Upper Level of Intake) Highest average daily nutrient intake that likely to pose no adverse health effect to 98% of the general population. (Intake above UL potential risk of adverse effects increases) o

Energy balance

****The relationship between energy in and energy out. Positive = weight gain Negative = weight loss o

EER

**(Estimated Energy Requirement)**the average dietary energy intake that is predicted to maintain energy balance in a healthy adult of defined age, sex, weight, height and level of physical activity consistent with good health. o

BMR

(Basal Metabolic Rate) is the rate at which the body expends energy for maintenance activities (Beating heart, contracting lungs, pumping of the veins, breathing) o

PAL

(Physical Activity Level): Level of activity rating to sedentary to intense o

Limitations

Approximate, an estimate and is it as in-perfect equation o

EER are calculated

in mJ. 1 mJ = 1,000 kJ o

Hypothalamus

is a brain centre that controls activities such as maintenance of water balance, regulation of body temperature and control of appetite. Message central – integrate messages about energy intake, expenditure and storage. Influence hunger, satiation, and satiety. o

Satiation

as food enters the GI tract hunger diminishes, satiation develops, receptors in the stomach and hormones such as cholecystokinin increase, the person begins to feel full. The response is that satiation occurs, and the person stops eating.

o

Satiety

the feeling of satiety continues to suppress hunger and allows a person to not eat again for a while. Whereas satiation tells us to ‘stop eating’, satiety reminds us to ‘not start eating again’ o

Hyponatremia

****Overconsumption of water in a short period of time. Water intoxication o

AI water/fluids

= (Approximately) 2.1L Female – 2.6L Male: Human adults consist of 55 – 65% water. o

Water/ fluids

maintain water balance to support vital functions ****Intracellular fluid makes up 2/3 of the body’s water ****intake from liquids, foods and metabolism must equal losses from the kidneys, skin, lungs and faeces o

1. 2. 3. 4. 5. 6. o

Water/fluids: Role & functions Carries nutrients and waste product Maintain the structure of large molecules Participate in metabolic reactions Solvent for minerals, vitamins, amino acids, glucose etc Lubricant and cushion around joints, eyes, spinal cord Regulation of body temperatureMaintain blood volume Water losses

Occur through urine output, water vapour from lungs, sweat and faeces; minimum 500mls/day o

Dehydration

****Develop when water output is not replaced o

Inadequate water intake

= Blood become concentrated, mouth dries, concentration of urine, shrinkage of organs and brains o

Thirst

****Response sensed by the mouth, hypothalamus and nerves o

Water sources

Foods, fluids (water, coffee, milk), fruit & vegetables

o

Hard water

= High concentration of calcium and magnesium o

Soft water

= High concentration of sodium and potassium o

Digestion

****The process of breaking-down food into its simplest form via bodily chemical and physical processes. o

Digestion system

Has 4 main components; transforming raw materials of food into nutrients and energy via chemical and physical processes 1. 2. 3. 4. o

Gastrointestinal tract Pancreas, gallbladder, liver Enzymes, nerves, hormones and blood Mesentery Human digestion

Occurs in 6 main steps that aims to reduce all macromolecules in food into their tiniest and most basic form 1. Ingestion chewing, teeth pulverise food 2. Chemical Salivary glands produce saliva that contains enzymes to further breakdown food 3. 4. 5. 6. 7. o

o

1. 2. 3. 4.

Propulsion Mechanical breakdown Chemical digestion Absorption Defecation Ingestion -> Elimination processes

Main organs of the digestive system and their role + functions Mouth Stomach Small intestine Large intestine

Absorption system of the small intestine: Processes 1. Small intestine is made up of finger-like projections called “Villi” 2. Villi increased the surface area of the small intestine allows for more absorption 3. Absorption of these simple molecules occur in the small intestine by diffusion into the blood vessels of the villus. o Hormonal and neuronal co-ordination of digestion and absorption o

CARBOHYDRATES 

Carbohydrates (COH) Compounds composed of carbon, oxygen and hydrogen arranged as monosaccharides or multiples of monosaccharides. One of the 6 nutrient classes o Energy yielding 17kJ/g o Organic macronutrient Carbohydrates sources o Bread, rice, pasta, starchy vegetables, fruit, dairy, alcohol – food containing fibre, sugars and starches o ADG’s recommends 45-65% of energy needs to come from carbohydrates Carbohydrate’s role and functions o Main source of energy kJ o Provides nearly all of the energy the human brain uses daily o Body stored carbohydrate as glycogen in tissue, liver and muscles o Breakdown of fatty acids and preventing ketosis Starch o

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****Complex carbohydrates (Polysaccharides) – Alpha bonds (easily digestible) 

Cellulose ****Major component of plant cell wall, indigestible by humans. Provides insoluble fibre facilitates defecation.

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Glycogen Storage of carbohydrates, provides about half the energy that muscle and other body tissues use.

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3 main classes of Carbohydrates + a subclass o Monosaccharides o Disaccharides o Complex Carbohydrates (Polysaccharides) Glycaemic index

Refers to how quickly a fixed amount of a food is converted into glucose. Which in turn effects how quickly it elevates blood sugars 

Glycaemic load How much a non-fixed amount affects blood glucose e.g portion vs standard serve

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Insulin ****Hormone synthesis in the pancreas. Body’s main tools for sugar management Prompts muscles and fat cells to let glucose in Conversion of sugar to energy Insulin sensitivity o ****The degree to which a unit of insulin lowers blood sugar o The more a given unit of insulin lowers blood sugar, the more sensitive you are to insulin Insulin resistance o o

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Reduction of insulin sensitivity; cells are less responsive o o 

Blood sugar fails to decrease, thus continuing to rise Leads to metabolic symptoms: High blood sugar and pressure, cardiovascular diseases and type II diabetes.

Fibre ****Plant-derived foods, human lack enzymes to digest fibre; joined by beta-bonds (non-digestible); slows absorption of sugar into the bloodstream preventing insulin spikes; processed by gut bacteria into fatty acids

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Dietary fibre Keep the digestive system health and consist of 2 types. Insoluble fibres o Soluble fibres Dietary Fibre (RDI/AI/UL) o

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AI/RD Male (adult): 30g/day, Female (adult): 25g/day

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No UL set due to risk weighing of consumer upper limit can have negative adverse effect Starch digestion

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Dietary fibre digestion

o

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Ketosis Process that occur when body doesn’t have enough carbohydrates to convert for energy. Instead, it burns fat and makes ketones which can be used for energy.

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Proteins CONH Amino-acids chain linked by peptide bonds in condensation reactions Macronutrient Energy yielding 17kJ/g Transport nutrients o Assist with chemical reactions o Hormones and enzymes o Building blocks of living organism o Consist of 20 amino acids, 9 of which are essential (can only be obtained via external sources) Amino acid o o o

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Micro-molecule structures that makes up protein; consist of Hydrogen atom Amine group Carboxyl group R group: Varies in the 20 amino acids Non-essential amino acids o o o o

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****Dispensable; body can create and produce

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Essential amino acids Body unable to make these, must obtained via external sources (food)

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Protein structure ****Consist of 4 sequences o o o o

Primary Secondary Tertiary structure Quaternary structure

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Peptide bond ****dehydration reaction (loss of H2O)

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Dipeptide ****2 linked amino acids

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Oligopeptide ****3-10 linked amino acids

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Polypeptide ****>10 linked amino acids

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Role of protein o Builds materials for growth and maintenance o Enzymes are proteins that facilitate in anabolic (building-up) and catabolic (breaking-down) chemical reactions o Hormones regulate body processes, some hormones are proteins, e.g., insulin o Transporters of lipids, vitamins, minerals and oxygen in the body o Act as pumps in cell membranes, transferring compounds from one side of the cell membrane to the other Sources of protein in diet ****Meat, fish, legumes and nuts, diary, grains, nuts and seeds

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Protein quality Foods that consist of all the 9 essential amino acids

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Protein intakes o EAR o RDI o UL Protein digestion and absorption

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Lipids CHO

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a family of compounds that includes triglycerides, phospholipids, and sterols; characterised by their insolubility in water o o o o

Accounts for 18-25% of body mass Organic compounds consist of carbon, hydrogen, and oxygen Energy yielding 37 kJ/g Hydrophobic

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Four main classes of lipids: o Fatty acids o Triglycerides o Phospholipids o Sterols Cholesterols ****most important sterols in the body; can be synthesised in the body but can be obtained via foods (eggs, meat, cheese, fish); vital component of cell membrane Production of sex hormone Assist in bile production Building blocks for tissues

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Hydronated ****Process where hydrogen is added to increase stability of the oil, it also in turn changes the 3D structure of the molecule

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Trans-fatty acids ****altered, have the same negative health effects as saturated fatty acids; don’t go rancid quickly; change texture of food

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Essential fatty acids ****Cannot be made by the body, e.g., Omega-3

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Sources of lipids in diet ****Dairy, meat, nuts & seeds, oils + fats

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Lipid’s roles and functions: o Provide energy, cushioning & insulation o Body can store unlimited amounts, when in excess develops adipose tissue (fat tissues) Linoleic acid ****Polysaturated omega-6 fatty acid occur, triglyceride

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a-linoleic acid ****essential omega-3 fatty acid

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LC n-3 (DHA+EPA+DPA) essential fatty acid

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Lipids intake

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Lipids digestion and absorption

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Carbohydrates, proteins and lipids main enzymes

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What is metabolism? “the sum total of all the chemical reactions that go on in living cells. Energy metabolism includes all the reactions by which the body obtains and expends the energy from food”

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Macronutrient metabolism

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How are carbohydrates metabolised?

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How are proteins and amino acids metabolised?

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How are fats and lipids metabolised?

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What are metabolic reactions? Metabolic pathways consist of 2 types of reaction o o

Catabolic = breakdown of molecules ****to yield energy Anabolic = Building up - synthesis of new molecules

2.

What are catabolic reactions, with examples? o o o

Tear things apart to release energy exergonic (generate energy) E.g. Break down glucose and convert it into ATP (body main source of energy, and drive anabolic reactions)

o o

What are anabolic reactions, with examples? Construct things - consume/require energy endergonic (consume/require energy) E.g. take monomer building blocks in food - like monosaccharides and fatty + animo acids - build them into polymers

o o

o o

How are carbohydrates catabolised to release/store energy in the body?

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Release: Carbohydrate → Glucose (Monosaccharide) —(Glycolysis)→ Pyruvate → Acetyl CoA → Electron transport chain → ATP Store: Glucose/Pyruvate → Glucose → Glycerol → Fatty acids → Triglycerides → Adipose tissue ATP is too unstable to store - cells stores glucose - when needed they get catabolise and convert into ATP

o o o

2. How are proteins catabolised in the body? o o

Protein → Amino acids (Glucogenic) → Pyruvate → Acetyl CoA → TCA (Kreb cycle) → Electron transport chain → ATP Protein → Amino acids (Ketogenic) → Acetyl CoA → TCA (Kreb) → Electron transport chain → ATP

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3. How are fats catabolised in the body? Lipids → Triglycerides → Glycerol & Fatty acids → ATP note: Glycerol → Pyruvate AND fatty acids → Acetyl coA 

3. What are the anabolic processes involving amino acids, carbohydrates and fats? o o o

Animo acids: re-building of amino acids into proteins - or fat Carbohydrates: Stores as glycogen or fat Fats: Stores as adipose tissue

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5. What is the role of hormones in metabolism? o o

Catabolic Anabolic

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6. Describe how some of these steps are reversible and irreversible o o

acetyle-CoA cannot be converted back t...