Nutrition

Unit Overview and Learning Objectives

• Goal of the Unit:

  • Develop a positive relationship with food.

  • Understand the importance of appropriately fueling the body.

  • Raise awareness for the role of media and marketing in influencing food choices.

• Nutritional Philosophy and Language:

  • Nutrition is defined as nourishing the body, not punishing it.

  • Foods are not categorized as "good" or "bad."

  • No judgment is made regarding food consumption.

  • Foods are classified based on density: Nutrient dense foods vs. Energy dense foods.

• Readiness to Learn:

  • Self-rating scale from $1$ to $5$:

    • $1$: Not at all ready to learn.

    • $3$: Okay/Ready to try.

    • $5$: Enthusiastic, confident, and focused.

  • The "Berry Street Education Model" strategies (Focus attention and Readiness to learn) are implemented to attend to new inputs.

Nutrient Classification and Definitions

• General Definition:

  • Nutrients are organic (carbon molecules produced by living organisms) and inorganic substances (molecules not containing carbon).

  • They are found in food and required by the body for the growth and maintenance of body systems.

• Two Primary Groups:

  • Macronutrients: Large molecules required by the body in large quantities.

  • Micronutrients: Small molecules required by the body in small quantities.

Macronutrients: Carbohydrates (CHO)

• Definition and Requirements:

  • A macronutrient required in large quantities.

  • Energy Production: $1\,gram$ of carbohydrates provides the body with $16\,kilojoules$ of energy.

  • Dietary Recommendation: Roughly $55\%$ of all energy intake should come from carbohydrates.

• Primary Functions:

  • Preferred source of energy for the body.

  • Maintenance of body temperature.

  • Waste elimination (specifically via fibre).

• Classification:

  • Simple Carbohydrates: Monosaccharides (e.g., fruits, honey, milk).

  • Complex Carbohydrates: Polysaccharides (e.g., wholegrain cereals, vegetables, fruit, legumes).

• Food Sources:

  • Cereal foods, breads, rice, pasta, sugars, honey, jam, sweets.

  • Milk, sports drinks, and sweetened drinks.

  • Fruit (Bananas, Grapes) and Vegetables (Potatoes, Carrots).

Fibre (Type of Carbohydrate)

• Identification:

  • A specific type of carbohydrate required in large quantities.

  • Recommended Intake: $25\,g$ of fibre daily.

  • Achieving Intake: Consuming $2$ to $3$ serves of fruit, $\frac{1}{2}$ cup of green leafy vegetables, or $1$ cup of cooked beans.

• Classification and Functions:

  • Insoluble Fibre:

    • Cannot be absorbed by the body.

    • Function: Absorbs water in the large intestine, softening faeces to make excretion easier.

    • Sources: Nuts, seeds, whole grain foods, skin of fruit and vegetables.

  • Soluble Fibre:

    • Takes longer to digest and satisfies hunger.

    • Function: Binds with "bad" cholesterol to reduce cholesterol levels; regulates blood glucose levels by delaying glucose absorption.

    • Sources: Fruit, vegetables, lentils, oat, bran.

Macronutrients: Protein

• Structure:

  • Made up of building blocks called amino acids.

• Amino Acid Classification:

  • Essential Amino Acids: Cannot be made by the body; must be consumed through food.

  • Non-Essential Amino Acids: Can be created by the body.

• Functions:

  • Energy Production: Acts as an energy source when carbohydrates and fats are depleted ($1\,gram = 17\,kilojoules$).

  • Body Maintenance: Essential for growth, development, repair, and replacement of body tissues.

  • System Support: Essential components of hormones, enzymes, and antibodies (immune system).

• Food Source Categories:

  • Complete Proteins: Contain all essential amino acids in necessary quantities (e.g., meat, fish, eggs, cheese, animal milk).

  • Incomplete Proteins: Do not contain all essential amino acids and should be eaten with other protein sources (e.g., wholegrain cereals, nuts, legumes, soy beans).

Macronutrients: Fats (Lipids)

• Functions:

  • High Energy Source: Eating $1\,gram$ of fat provides the body with $37\,kilojoules$ of energy.

  • Dietary Recommendation: Roughly $30\%$ of all energy should come from fats.

  • Cellular Health: Required for development and maintenance of cell membranes, allowing transport of nutrients, gases, and waste.

  • Vitamin Transport: Carries fat-soluble vitamins (A, D, E, and K) around the body.

• Classification and Sources:

  • Bad Fats:

    • Saturated Fats: Fatty meats, full-fat dairy, butter, coconut and palm oil.

    • Trans Fats: Deep-fried foods, commercially baked biscuits/pastries/pies, cakes, margarines, shortening, fried chips.

  • Healthier Fats:

    • Monounsaturated Fats: Olive oil, cashews, peanuts, hazelnuts, avocados.

    • Polyunsaturated Fats (Omega-3 and Omega-6): Mackerel, trout, sardines, tuna, salmon, canola/soy oils, walnuts, and Brazil nuts.

Water

• Classification: Not technically a macronutrient, but a substance required in large amounts.

• Functions:

  • Comprises $50-75\%$ of body mass.

  • Key component of cells, tissues, blood, and metabolic reaction mediums.

  • Assists in weight maintenance by reducing hunger while contributing $0\,kilojoules$.

• Intake Recommendation: $1.5 - 2\,litres$ is generally sufficient for most days.

• Sources: Tap/bottled water, tea, coffee, watermelon, apple, orange, pineapple, celery, lettuce, cucumber, tomato.

Micronutrients: Minerals

• General Role: Essential for many chemical reactions within the body; present in bones, teeth, muscles, soft tissues, blood, and nerve cells.

• Calcium:

  • Function: Building hard tissues (teeth, bone, cartilage). Crucial during youth for maximizing bone density. Important for nerve and muscle (heart) functioning.

  • Sources: Dairy (milk, cheese, yoghurt), sardines/salmon with bones, green leafy vegetables (broccoli, spinach), fortified soy milk, orange juice.

• Sodium:

  • Function: Regulates body fluids (water, blood) through osmosis (fluid is drawn to sodium); helps balance fluid in and out of cells. Transmission of nerve impulses and muscle contraction.

  • Sources: Table salt, olives, fish, meat (pork), cheese, processed foods (tomato sauce, packet soups, canned veg, pizzas, pies).

• Iron:

  • Function: Essential for blood production; forms the "haem" part of haemoglobin (oxygen carrier). Forms myoglobin to store oxygen in muscle cells.

  • Absorption: Vitamin C dramatically increases iron absorption.

  • Sources: Red meat, poultry (turkey, chicken), fish, eggs, nuts, seeds, brown rice, leafy greens.

Micronutrients: Vitamins

• Vitamin C:

  • Function: Building collagen (protein for skin, connective tissue, tendons, ligaments). Promotes iron absorption.

  • Sources: Kiwi fruit, broccoli, blackcurrants, oranges, strawberries.

• Vitamin D:

  • Function: Facilitates the absorption of calcium from the intestine into the bloodstream.

  • Sources: Sunlight, fish (tuna, salmon, sardines), fortified milk, cereals, and orange juice.

• B-Group Vitamins (B1, B2, B3):

  • Function: Metabolism and releasing energy from carbohydrates; cell respiration; circulation; nervous system function; red blood cell formation.

  • Sources: Vegemite, wholegrain breads/cereals, eggs, fish, meats, dark-green leafy vegetables, milk.

• Vitamin B12:

  • Function: Red blood cell formation; rapid DNA synthesis during cell division; nervous system maintenance; energy metabolism.

  • Sources: Liver, meat, poultry, fish, seafood, eggs, milk, vegemite.

Food Labeling Laws (FSANZ)

• Governance: Food labeling laws are governed by FSANZ (Food Standards Australia and New Zealand).

• Mandatory Requirements for Packaged Food:

  • Nutrient Information Panel (NIP).

  • Use-by or best-before date.

  • Country of origin.

  • Manufacturing details.

• Nutrient Information Panels (NIPs):

  • Provide data on energy and key nutrients.

  • Mandatory on most foods except herbs/spices, mineral water, tea, coffee, and unpackaged foods.

  • Must be present if a health claim is made.

  • Selection Criteria based on NIP:

    • Total Fat: Aim for less than $10\,g$ per $100\,g$ ($2\,g/100\,g$ for dairy; $15\,g/100\,g$ for cheese).

    • Saturated Fat: Aim for the lowest, ideally less than $3\,g$ per $100\,g$.

    • Fibre: Choose breads/cereals with $3\,g$ or more per serve.

    • Sodium: Less than $400\,mg$ per $100\,g$ is good; less than $120\,mg$ per $100\,g$ is best.

    • Sugar: Avoid if it exceeds $15\,g$ per $100\,g$ and is listed high in ingredients.

  • Ingredients List: Listed from greatest to smallest by weight.

Dietary Terminology

• Standard Serve: The recommended amount of a particular food that constitutes "one serve" from the five food groups (e.g., $1$ medium tomato or $\frac{1}{2}$ cup cooked greens).

• Serving Size: The amount chosen by the food manufacturer; generally not linked to official health recommendations.

• Portion: How much of a certain food an individual actually chooses to eat.

• Recommended Daily Intake (RDI): Levels of intake of essential nutrients based on scientific knowledge adequate to meet the needs of healthy people. Developed/monitored by the National Health and Medical Research Council (NHMRC).

Australian Food Models and Guidelines

• Australian Dietary Guidelines (Created by the Australian Government):

  1. To achieve/maintain healthy weight, be active, and choose nutritious food to meet energy needs.

  2. Enjoy a wide variety of nutritious foods from the five groups and drink plenty of water.

  3. Limit intake of saturated fat, added salt, added sugars, and alcohol.

  4. Encourage, support, and promote breastfeeding.

  5. Care for your food (prepare and store safely).

  • Target Audience: Health professionals (doctors, dieticians, educators).

• Australian Guide to Healthy Eating (AGHE):

  • A visual food selection guide representing the proportion of five food groups.

  • Target Audience: The everyday Australian.

• Healthy Eating Pyramid (HEP):

  • Developed by Nutrition Australia.

  • Foundation layers emphasize plant foods. Includes herbs/spices and categories for "healthy fats."

• Health Star Rating (HSR) System:

  • Endorsed by the government in 2014.

  • Voluntary system labeling food from $\frac{1}{2}$ star to $5$ stars.

  • Compares similar products based on energy and risk nutrients (sugar, fat).

Diet-Related Diseases and Risk Nutrients

• Main Risk Nutrients: Fats, Carbohydrates, and Sodium.

• Obesity: Caused by excess kilojoule intake over long periods; glucose not used is stored as adipose tissue (body fat).

• Cardiovascular Disease (CVD): Linked to increased cholesterol (artery blockage), high blood pressure, and heart attack. Obesity adds extra pressure to the heart.

• Diabetes (Type 2): Prolonged overconsumption of sugar/carbohydrates leads to high blood glucose or impaired glucose regulation. Trans fats can interfere with cell membranes.

• Hypertension (High Blood Pressure): High sodium draws fluid out of cells, increasing blood volume.

• Colorectal Cancer: Identified in the rubric as a major nutrition-related disease.

Question Technique: C.A.r.e.F.u.L

• C = Command term: Circle (e.g., Identify, Complete, Select, Describe).

• A = Allocated marks: Note mark allocation to plan depth (e.g., $1$ mark vs. $2$ marks).

• F = Focus of question: Highlight (e.g., micronutrients, function, RDI).

• L = Limiting terms: Underline (e.g., "one trend," "must represent both," "short-term OR long-term").

Questions & Discussion

• Magda’s Big National Health Check:

  • What did you find interesting and/or shocking?

  • Why do you think we’re learning about different influences on our eating behaviors (Income, Location, Housing, Marketing)?

• Comparing Food Models (AGHE vs. HEP):

  • Which visual representation is clearer? Why?

  • Are these models appropriate for all ages, cultures, and diets?

  • What are potential limitations and how could they be improved?

• Health Star Rating (HSR) Analysis:

  • How does the Health Star Rating influence your perception of the healthiness of a product?

• What the World Eats Discussion:

  • What trends were noticed regarding cost per week and family health?

  • What factors (financial, cultural, geographical) influence global food behaviors?

• AGHE vs. Indigenous AGHE Comparison:

  • What are the similarities and differences?

  • Is one more suitable than the other for rural or specific cultural populations?