Section Revision: Nutrition and Health

This lesson provides a comprehensive revision of nutrition and health content for the AQA GCSE Food Preparation and Nutrition exam (8585), covering macronutrients, micronutrients, nutritional needs across life stages, and diet-related health problems.

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Macronutrients

Macronutrients are needed in large amounts and provide energy and essential functions:

Nutrient	Function	Sources	Deficiency
Protein	Growth and repair of body cells; secondary energy source; makes enzymes, antibodies, hormones	Meat, fish, eggs, dairy, pulses, nuts, soya, Quorn	Kwashiorkor (severe); poor growth, weak muscles, poor wound healing
Carbohydrate	Primary energy source	Starchy: bread, pasta, rice, potatoes. Sugary: fruit, table sugar, honey	Lack of energy, tiredness, ketosis
Fat	Concentrated energy source; insulation; protects organs; carries fat-soluble vitamins (A, D, E, K)	Butter, oil, cheese, oily fish, nuts, avocado, meat	Lack of energy; poor absorption of fat-soluble vitamins
Fibre (NSP)	Promotes healthy digestive system; prevents constipation; helps maintain steady blood glucose	Wholemeal bread, brown rice, fruit, vegetables, pulses, oats	Constipation, diverticular disease, increased risk of bowel cancer
Water	Maintains hydration; regulates body temperature; transports nutrients; removes waste	Drinks, fruit, vegetables, soup	Dehydration, headaches, kidney problems

Types of Protein

Type	Description	Examples
HBV (High Biological Value)	Contains all essential amino acids	Meat, fish, eggs, soya, quinoa
LBV (Low Biological Value)	Missing one or more essential amino acids	Pulses, cereals, nuts, seeds
Protein complementation	Combining two LBV proteins to provide all essential amino acids	Beans on toast; rice and lentils; hummus and pitta

Types of Fat

Type	Effect on Health	Sources
Saturated fat	Raises LDL ("bad") cholesterol; increases risk of heart disease	Butter, cheese, fatty meat, cakes, biscuits, coconut oil
Unsaturated fat (mono)	Lowers LDL cholesterol; protects heart health	Olive oil, avocado, almonds
Unsaturated fat (poly)	Includes omega-3 and omega-6; essential for brain function and heart health	Oily fish (salmon, mackerel), sunflower oil, walnuts
Trans fats	Raises LDL, lowers HDL; very harmful	Some processed foods, hydrogenated vegetable oil

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Micronutrients

Micronutrients are needed in small amounts but are essential for body functions:

Vitamins

Vitamin	Function	Sources	Deficiency
A (retinol)	Vision (especially night vision); healthy skin and immune system	Liver, carrots, sweet potato, dairy, eggs	Night blindness; dry skin
B1 (thiamin)	Energy release from carbohydrates; nervous system	Wholegrain cereals, pork, fortified flour	Beriberi; fatigue
B2 (riboflavin)	Energy release; healthy skin	Milk, eggs, fortified cereals	Cracked lips; sore tongue
B9 (folic acid/folate)	Red blood cell formation; prevents neural tube defects in pregnancy	Green leafy vegetables, fortified cereals, liver, pulses	Megaloblastic anaemia; neural tube defects (spina bifida)
B12	Red blood cell formation; nervous system	Meat, fish, dairy, eggs, fortified foods	Pernicious anaemia; nerve damage
C (ascorbic acid)	Immune system; collagen production; iron absorption; antioxidant	Citrus fruits, peppers, strawberries, broccoli, potatoes	Scurvy (bleeding gums, poor wound healing)
D	Calcium absorption; healthy bones and teeth	Sunlight, oily fish, eggs, fortified foods	Rickets (children); osteomalacia (adults)

Minerals

Mineral	Function	Sources	Deficiency
Calcium	Strong bones and teeth; muscle contraction; blood clotting	Dairy, green leafy vegetables, fortified foods, tinned fish with bones	Osteoporosis (later life); rickets
Iron	Red blood cell production (haemoglobin); oxygen transport	Red meat, dark green vegetables, fortified cereals, pulses	Iron deficiency anaemia (tiredness, pallor, weakness)
Sodium	Nerve and muscle function; fluid balance	Salt, processed foods, cheese, bread	Rare; muscle cramps. Excess causes high blood pressure
Phosphorus	Strong bones and teeth; energy release	Dairy, meat, fish, eggs, cereals	Rare; weak bones

flowchart LR
    A["Deficiency<br/>Diseases"] --> B["Scurvy<br/>Lack of Vitamin C"]
    A --> C["Rickets<br/>Lack of Vitamin D"]
    A --> D["Anaemia<br/>Lack of Iron<br/>or B12"]
    A --> E["Osteoporosis<br/>Lack of Calcium<br/>& Vitamin D"]
    A --> F["Night Blindness<br/>Lack of Vitamin A"]

    style B fill:#e74c3c,color:#fff
    style C fill:#e67e22,color:#fff
    style D fill:#f39c12,color:#000
    style E fill:#3498db,color:#fff
    style F fill:#8e44ad,color:#fff

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Nutritional Needs Across Life Stages