Diet and Nutrition

(W1) What are the main categories of nutrients?

• Macronutrients: carbohydrates, fats, proteins

• Micronutrients: vitamins, minerals, phytochemicals

• Water is essential

What’s the difference between essential and non-essential nutrients?

• Essential: must be consumed from diet

• Non-essential: body can produce the

What are the short-term benefits of good nutrition?

Energy, digestion, focus, mood, sleep, blood flow, weight control, clear skin, strong nails

What happens during digestion starting from the mouth to the stomach?

• Mouth: amylase breaks down carbs, forms bolus

• Epiglottis prevents food from entering lungs

• Oesophagus moves food via peristalsis

• Stomach uses mechanical + chemical digestion (pepsin breaks proteins)

What is the function of the small intestine in digestion?

• Divided into duodenum, jejunum, ileum

• Absorbs nutrients through villi

• Pancreas releases enzymes

What are the roles of the liver, gallbladder, appendix, and large intestine?

• Liver: produces bile, removes toxins

• Gallbladder: stores/releases bile

• Appendix: may help fight infection

• Large intestine: converts left over food into waste

What factors influence the speed of digestion?

• Speed up: caffeine, exercise, sweeteners

• Slow/cause loose stools: fat, stress

• Hydration is crucial (feces = ~70% water)

What are key dietary features for heart health?

• Mediterranean diet (whole foods, low processed)

• Fruit/veg: antioxidants

• Soy: lowers lipids & clotting

• Wholegrains: improve cholesterol & insulin

What is IBD and how does it affect digestion?

IBD includes Crohn’s (entire gut) and UC (large intestine) → causes pain, diarrhoea, weight loss, fever

What are long-term effects of poor nutrition?

Type 2 diabetes, heart disease, cancers, high BP, dementia, IBD, haemorrhoids, gout, varicose veins

How can nutrition help prevent cancer?

• Limit processed foods

• Avoid HCA compounds (e.g. from grilled meats)

What are nutritional issues during cancer treatment?

Poor appetite, cachexia (muscle loss), nausea, vomiting, loss of taste

What supports cancer recovery nutritionally?

• Consume high-protein foods to rebuild muscle mass

• Eat energy-dense meals to meet increased energy needs

• Include nutrient-rich foods (vitamins, minerals, antioxidants) to support healing and immunity

What are treatments and management tips for IBD and diverticulosis?

• IBD: Omega-3, avoid caffeine/spices

• Diverticulosis: avoid seeds/nuts, eat simple/soft foods, identify trigger foo

How does nutrition affect eyesight?

• Prevents/limits macular degeneration, glaucoma, cataracts

• Antioxidants & blood lipids improve eye blood flow

What are key nutrient concerns in Australians’ diets?

• Iron: women need more (menstruation)

• Sodium: avg. 2720mg/day (too high → high BP)

• Calcium: 44% of men & 38% of women are deficient

What are the differences in fruit & grain intake between men and women?

• Men closer to grain recs (0.5 below 5.5 serves)

• Women closer to fruit recs (0.7 below 1.3 serves)

Describe the average Australian diet and its macronutrient breakdown

• High in processed/fried foods, salt, alcohol

• Carbs: 45%, Fat: 30%, Protein: 25%

(W2) What are the key functions of fats?

Dense energy (~9 kcal/g) • Protect organs • Insulation • Carry fat-soluble vitamins A, D, E, K

Name the main fat types with examples.

Saturated (animal fats, coconut oil) • Monounsaturated (olive oil, avocado) • Polyunsaturated (walnuts, sunflower oil) • Trans fats (processed foods; avoid)

Visible vs invisible fats and how the body stores fat?

Visible: butter/oils/meat fat

Invisible: processed foods/pastries

Excess stored as adipose tissue; liver can convert carbs/protein into fat and transport in the body as energy.

Core roles of protein in the body?

Growth & repair • Enzymes • Hormones • Antibodies • Blood components • Muscle turnover ~1–2%/day

What boosts muscle protein synthesis most effectively?

Resistance training + adequate protein (20–30 g/meal) • Leucine-rich sources • Timing/source/prep affect absorption

Soluble vs insoluble dietary fibre: functions and sources?

Soluble: forms gels, lowers cholesterol (fruits, vegetables, legumes) • Insoluble: adds bulk, speeds transit (whole grains, nuts, seeds)

Other fibre forms and examples (incl. common polymers)?

Resistant starch (legumes, unripe bananas)

Phytic acid (binds minerals; minor issue if diet varied) Cellulose (veg/fruit/legumes)

Hemicellulose (cereals)

Pectins (apples/citrus)

Gums/mucilages (thickeners)

Lignin (nuts/seeds)

Carbohydrates: primary roles and main types?

Primary energy for brain

Glycogen in muscle/liver

Spares protein/fat

Simple sugars (mono/disaccharides) vs complex (starch, glycogen, fibre)

Carb digestion, key hormones, and Glycaemic Index ranges?

Digestion: amylase (mouth), enzymes (small intestine); fibre slows absorption

Hormones: insulin ↓ glucose; glucagon/epinephrine ↑ glucose

GI: low <55, medium 56–69, high ≥70

Energy metabolism: what are anabolism vs catabolism and energy yields?

Anabolism builds; catabolism breaks down

Energy yields: carbs 4 kcal/g, protein 4, fat 9, alcohol 7

Main components of energy expenditure and typical percentages? What is excess energy stored as (long and short term)

BMR 60–70%

Diet-induced thermogenesis ~10% (highest for protein) Activity thermogenesis 5–30% (exercise + daily movement)

Glycogen (short term), fat (long term)

(W3) Water- vs fat-soluble vitamins: key contrasts?

Water-soluble (B-complex, C): limited storage, excess excreted, heat-sensitive

Fat-soluble (A, D, E,): stored, need bile, higher overdose risk, more stable in cooking

What are EAR, RDI, AI, and UL?

EAR: meets ~50% needs

RDI: ~97–98%

AI: best estimate when no RDI

UL: highest average daily intake likely to pose no risk

Vitamin C essentials: functions, sources, RDI, deficiency/toxicity, at-risk groups?

Functions: collagen, immunity, wound healing, iron absorption, antioxidant

Sources: citrus, berries, kiwi, broccoli, capsicum

RDI 45 mg/day

Deficiency: scurvy

Toxicity >1000 mg/day: GI upset/kidney stones

At-risk: smokers, elderly, alcohol misuse, restrictive diets Cooking can reduce by ~30–40%

B-vitamins: main roles and hallmark deficiencies?

Energy release: B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B7 (biotin) • Metabolism/cell division: B6 (pyridoxine), B9 (folate), B12 (cobalamin)

Deficiencies: B1—beriberi/Wernicke-Korsakoff; B2—cheilosis/eye issues; B3—pellagra(diarrhea, death); B6—dermatitis/anaemia/neuropathy (toxicity → nerve damage); B9—macrocytic anaemia/NTD, risk; B12—pernicious anaemia/neurologic; B5/B7—rare

Vitamin A: key points?

Forms: retinol/retinal/retinoic acid, beta-carotene • Functions: vision, epithelial health, immunity, growth • Deficiency: night blindness

Toxicity: teratogenicity/bone issues/orange skin

Sources: liver, fish oils, dairy, eggs, carrots, leafy greens, mango, pumpkin

Vitamin D: forms, activation, roles, risks, sources, toxicity?

Forms: D2 (plants), D3 (sun/animals)

Activation: liver & kidneys

Roles: Ca/P absorption, bone/immune

Risks for deficiency: elderly, dark skin, low sun, veiling, obesity

Sources: sunlight, fatty fish, egg yolk, fortified foods Toxicity: hypercalcemia/soft-tissue calcification

Vitamin E and Vitamin K: quick hits?

Vitamin E (alpha-tocopherol): antioxidant; deficiency rare (haemolytic anaemia in infants); toxicity rare; sources: nuts, seeds, veg oils, greens, wholegrains

Vitamin K (phylloquinone/menaquinone/menadione): blood clotting & bone proteins; deficiency → bleeding (newborns); sources: leafy greens, gut bacteria

Macrominerals (full names): roles and key sources?

Calcium—bones/teeth, clotting, muscle/nerve

Phosphorus—bones/ATP

Magnesium—>300 reactions (energy, BP, glucose)

Sodium—fluid balance/BP/nerves

Potassium—BP/nerves/muscle • Chloride—stomach acid/fluid balance

Sulphur—amino acids/protein structure/detox; Sources: dairy, nuts, wholegrains, leafy greens, meats, table salt, processed foods

Trace minerals (full names): roles and notable points?

Chromium—insulin function/glucose metabolism

Copper—RBC formation/nerves/immunity

Fluoride—teeth & bone health

Iodine—thyroid hormone/metabolism

Iron—haemoglobin/oxygen transport (vitamin C boosts absorption)

Manganese—bone formation/clotting/metabolism Molybdenum—enzyme cofactor/detox

Selenium—antioxidant/thyroid/immunity

Zinc—immunity/DNA synthesis/growth/wound healing

Australia’s health expenditure & main chronic disease burdens?

$170 billion (2015–16); major burdens: CVD, cancers, type 2 diabetes.

What does epidemiology study?

Incidence/prevalence, risk factors, high-risk groups, guides prevention, relating to health problems

CVD risk factors & outcomes?

Risk factors: poor diet, inactivity, tobacco, alcohol, hypertension.
Outcomes: high BP, glucose, lipids, obesity.

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Type 2 diabetes overview?

85% of global diabetes; insulin resistance + insufficient insulin;

risks = age >40, obesity, processed food, inactivity, alcohol, smoking, family history, Indigenous Australians (>35).

Current Australian nutrition patterns?

⅓ energy from discretionary foods; high sugar, sat fat, sodium; poor guideline adherence; high obesity, low physical activity; SES/remoteness affect diet.

BMI strengths & limitations?

Population tool, not individual; ignores fat distribution, ethnicity, muscle mass.

Waist circumference & WHR risk thresholds?

Waist = visceral fat predictor of CVD, stroke, T2D. WHR: <0.9 men, <0.8 women.

Gold standard & key biochemical health measures?

DEXA scan; blood glucose, cholesterol, iron, bone mineral density, blood pressure.

Diagnostic cut-offs for diabetes, cholesterol & blood pressure?

Diabetes: fasting >7 mmol/L or HbA1c >6.5%.
Cholesterol: 33% Australians (30–65) high.
BP: Ideal 120/80; hypertension ↑CVD/stroke/kidney risk.

Infant growth & nutrition?

Weight doubles by 5 months, triples by 1 year; breast milk/iron-fortified formula; solids at 6 months; needs high energy, vitamins A, C, D, iodine.

Breast milk vs. formula?

Breast milk = immune factors (colostrum, lactoferrin, bifidus); formula = nutrient mimic, fewer antibodies, safe prep needed.

Childhood energy needs & nutrition concerns?

3300 kJ (1 yr) → 8500 kJ (10 yrs). Concerns: high sugar/fat, low iron, allergies, intolerances.

Childhood obesity: causes, effects, prevention?

Causes: poor diet, inactivity, parental obesity, sugary drinks, convenience foods.
Effects: early puberty, ↑CVD, T2D, psychosocial issues.
Prevention: healthy diet, activity, reduce sedentary time, parental role modelling.

Adolescent nutrition needs?

Iron (menstruation/lean mass), calcium + vitamin D (peak bone mass).

Adolescent diet: energy needs & challenges?

8200 kJ (inactive female) → 14,000 kJ (active male).
Challenges: peer pressure, skipped meals, snacks/soft drinks, ⅓ meals outside home.