Food and Nutrition for Good Health
Welcome to your revision guide for Food and nutrition for good health! Nutrition might seem like a huge topic with lots of scientific terms, but don't worry if this seems tricky at first. We are going to break everything down step-by-step with clear examples, simple memory tricks, and direct links to what CCEA examiners want to see in your exam.
Think of your body like a high-performance car: the food you eat is the fuel and spare parts. Choosing the right fuel keeps everything running smoothly, repairs damage, and gives you the energy you need every day.
---1. National Dietary Guidelines
The Eatwell Guide
The Eatwell Guide is the official UK government nutritional model. It shows the proportions of different food groups we should eat across a day or week to achieve a healthy, balanced diet. It is divided into five main food groups:
1. Fruit and vegetables: Makes up over a third of our daily intake. We should aim for at least 5 portions of a variety of fruit and vegetables every day to provide essential vitamins, minerals, and dietary fibre.
2. Potatoes, bread, rice, pasta and other starchy carbohydrates: Also makes up over a third of the guide. Choose higher fibre or whole grain versions (like brown rice or wholemeal bread) for sustained energy and healthy digestion.
3. Dairy and alternatives: Good sources of protein and calcium. The guidance recommends choosing lower fat and lower sugar options (such as semi-skimmed milk or low-fat plain yoghurt).
4. Beans, pulses, fish, eggs, meat and other proteins: Vital for body growth and repair. The guide encourages eating more beans and pulses (naturally low in fat and high in fibre) and aiming for 2 portions of sustainably sourced fish per week, one of which should be oily (like salmon or mackerel).
5. Oils and spreads: These are fats, so they should only be consumed in small amounts. Always choose unsaturated oils and spreads (such as rapeseed or olive oil) instead of saturated fats.
The 8 Tips for Eating Well
The NHS and Public Health Agency outline eight practical rules to help us put nutritional science into everyday practice:
1. Base meals on higher fibre starchy carbohydrates: Keeps you full and provides steady energy.
2. Eat lots of fruit and veg: Aim for at least 5-a-day.
3. Eat more fish, including a portion of oily fish: Supplies essential omega-3 fatty acids for heart health.
4. Cut down on saturated fat and sugar: Lowers the risk of heart disease and tooth decay.
5. Eat less salt: Adults should consume no more than 6g of salt per day to prevent high blood pressure.
6. Get active and be a healthy weight: Balances energy intake (food) with energy output (movement).
7. Do not get thirsty: Drink 6 to 8 glasses of fluid every day (water, lower-fat milk, tea, or coffee).
8. Do not skip breakfast: Jump-starts your metabolism and provides essential morning nutrients.
Key Takeaway: Balance is key! Over two-thirds of your daily plate should come from plant foods (starchy carbohydrates, fruit, vegetables, beans, and pulses).
---2. Dietary Reference Values (DRVs)
Scientists use Dietary Reference Values (DRVs) to estimate the amount of energy and nutrients required by different groups of healthy people. You must be able to distinguish between these three key terms for the exam:
EAR (Estimated Average Requirement): This is an estimate of the average daily need for energy or a nutrient. Approximately \(50\%\) of a group will need more than the EAR, and \(50\%\) will need less.
RNI (Reference Nutrient Intake): The amount of a nutrient that is enough to meet the dietary needs of almost all (\(97.5\%\)) people in a specific group. If you meet the RNI, you are almost certainly getting enough.
LRNI (Lower Reference Nutrient Intake): The lowest amount of a nutrient that is sufficient for only a tiny minority (\(2.5\%\)) of people. Anyone consuming less than the LRNI is very likely to develop a nutrient deficiency.
Memory Trick: Think of RNI as the Reliable Nutrition Intake for nearly everyone, while EAR is right in the middle (average).
---3. Macronutrients: The Building Blocks
Macronutrients are nutrients that the body needs in large quantities every day: Proteins, Fats, and Carbohydrates.
A. Proteins
Protein is essential for the growth of new cells, the repair of damaged tissue (such as healing wounds), and the maintenance of body structures. Proteins are made of smaller building blocks called amino acids.
High Biological Value (HBV) Proteins: Contain all the essential amino acids that our bodies cannot make on their own. Found mainly in animal sources (meat, fish, poultry, eggs, milk, cheese) as well as soya beans and quinoa.
Low Biological Value (LBV) Proteins: Lack one or more of the essential amino acids. Found in plant foods like peas, beans, lentils, nuts, seeds, and cereals.
B. Fats (Lipids)
Fat is needed for concentrated energy, insulating the body to keep it warm, protecting vital organs (like the kidneys) from physical shock, and providing and transporting the fat-soluble vitamins (A, D, E, and K).
Saturated Fats: Usually solid at room temperature and mainly come from animal sources (butter, lard, fatty meats) and tropical oils (palm oil, coconut oil). Eating too much saturated fat raises blood cholesterol.
Monounsaturated Fats: Contain one double bond in their chemical structure; help protect the heart (found in olive oil, avocados, and almonds).
Polyunsaturated Fats: Contain two or more double bonds; include essential omega fatty acids (found in oily fish, sunflower oil, and walnuts).
C. Carbohydrates
Carbohydrates are the body's main and preferred source of energy. They are broken down into three main categories:
1. Sugars: Simple carbohydrates that release energy quickly.
- Intrinsic sugars: Naturally built into the cellular structure of whole foods, such as fresh fruits and vegetables.
- Extrinsic sugars: Sugars not bound inside cell structures, such as the lactose in milk or free sugars added to cakes, biscuits, sweets, and table sugar.
2. Starch: Complex carbohydrates found in bread, potatoes, rice, pasta, and cereals. They break down slowly, releasing steady energy.
3. Dietary Fibre (NSP - Non-Starch Polysaccharide): The indigestible structural part of plant foods. Fibre keeps the digestive system healthy, adds bulk to stools, prevents constipation, and helps reduce the risk of bowel disorders.
Key Takeaway: Choose HBV or balanced LBV proteins for body repair, unsaturated fats instead of saturated fats, and starchy carbohydrates rich in dietary fibre.
---4. Micronutrients: Vitamins and Minerals
Micronutrients are required by the body in very small amounts (milligrams or micrograms), but they are absolutely essential for vital metabolic functions.
Fat-Soluble Vitamins
These vitamins dissolve in fat and can be stored in the liver and fatty tissues of the body.
Vitamin A (Retinol / Beta-Carotene):
- Function: Keeps eyesight sharp (especially night vision), supports the immune system, and maintains healthy skin.
- Sources: Retinol is found in liver, dairy products, and oily fish; beta-carotene (which the body converts into Vitamin A) is found in brightly coloured orange and green vegetables like carrots, sweet potatoes, and spinach.
Vitamin D (Cholecalciferol):
- Function: Helps the body absorb calcium to build and maintain strong bones and teeth.
- Sources: Sunlight on the skin, oily fish, egg yolks, and fortified breakfast cereals or spreads.
Water-Soluble Vitamins
These dissolve in water, cannot be stored in the body for long, and are lost through urine, meaning we need them regularly.
Vitamin B Group:
- Vitamin B1 (Thiamin), B2 (Riboflavin), and B3 (Niacin): Help release energy from the food we eat and maintain a healthy nervous system (found in whole grains, meat, and fortified flour).
- Vitamin B12: Crucial for red blood cell formation and nerve function (found in meat, fish, eggs, dairy, and fortified yeast extract).
- Folate / Folic Acid: Crucial for cell division and the healthy development of an unborn baby's spine (found in green leafy vegetables, peas, oranges, and fortified cereals).
Vitamin C (Ascorbic Acid):
- Function: Helps wounds heal, assists the absorption of non-haem iron in the gut, acts as an antioxidant, and maintains healthy connective tissues.
- Sources: Citrus fruits (oranges, lemons), blackcurrants, strawberries, bell peppers, and broccoli.
Key Minerals
Calcium: Works together with Vitamin D to build strong bones and teeth, assist normal blood clotting, and support muscle function (found in milk, cheese, yoghurt, canned fish with soft edible bones, and fortified plant milks).
Iron: Essential for making haemoglobin in red blood cells, which carries oxygen around the body. A lack of iron leads to tiredness, lack of energy, and iron-deficiency anaemia (found in red meat, liver, spinach, lentils, and fortified cereals).
Sodium: Controls body fluid balance and helps nerves and muscles work correctly. However, too much increases blood pressure (found in table salt and processed foods).
Potassium: Helps regulate fluid balance, heart rhythm, and muscle contraction (found in bananas, potatoes, and dark leafy vegetables).
Fluoride: Strengthens tooth enamel and helps resist tooth decay (found in fluoridated drinking water, tea, and seafood).
Iodine: Needed to produce thyroid hormones, which control metabolic rate (found in seafood, fish, and dairy foods).
5. Dietary Life Stages
Different groups of people have distinct nutritional priorities depending on their stage of growth and lifestyle.
Infants and Toddlers
Infants and young children have tiny stomachs but are growing very rapidly. They need nutrient-dense meals packed with energy, protein, and calcium.
- Important Safety Caution: Avoid whole nuts to prevent choking hazards, and do not add salt to their food, as their immature kidneys cannot process it.
Adolescents (Teenagers)
Adolescence is a major growth spurt requiring plenty of energy and protein.
- Calcium and Vitamin D: Essential during teenage years to achieve maximum peak bone mass, reducing the risk of osteoporosis later in life.
- Iron and Vitamin C: Teenage girls especially have increased iron requirements to replace blood lost during menstruation. Pair iron-rich foods with Vitamin C to maximise iron absorption.
Pregnancy and Lactation
A pregnant mother is nourishing herself and her developing baby.
- Folic Acid (Folate): Essential before conception and during the first 12 weeks of pregnancy to prevent Neural Tube Defects (NTDs) such as Spina Bifida.
- Iron: Needed to supply the extra blood supply for the growing placenta and foetus.
- Lactation (Breastfeeding): Requires extra fluids and calcium to support milk production.
Older Adults
Metabolism slows down and older adults often become less physically active, meaning their overall daily energy needs decrease.
- Nutrient Density: Meals must remain packed with nutrients despite smaller portion sizes.
- Vitamin D and Calcium: Essential to protect against bone loss and fractures.
- Dietary Fibre and Fluids: Needed to maintain bowel regularity and prevent constipation, as digestion slows with age.
6. Exam Pitfalls, Calculations & Command Words
1. Salt vs Sodium Calculation
Do not confuse salt with sodium on food packaging! To convert sodium to salt, use this standard formula:
\(\text{Salt (g)} = \text{Sodium (g)} \times 2.5\)
Example: If a ready meal label states it contains \(0.8\text{ g}\) of sodium:
\(\text{Salt} = 0.8 \times 2.5 = 2.0\text{ g of salt}\)
Remember, the daily maximum recommended limit for an adult is 6g of salt.
2. Avoid Vague Answers
Examiners will penalise statements like "Oranges are healthy" or "Milk is good for you."
Always explain why: "Oranges provide Vitamin C, which helps the body absorb iron and maintain a healthy immune system." or "Milk provides calcium, which is needed by adolescents to build peak bone mass."
3. Understand the Command Words
Describe: State the facts and characteristics clearly (e.g., "Describe the function of iron." \(\rightarrow\) State that it forms haemoglobin to transport oxygen).
Explain: Provide reasons and show causes/effects using the word "because" or "therefore" (e.g., "Explain why a teenage girl needs more iron." \(\rightarrow\) Explain the loss of blood during menstruation and the need to prevent anaemia).
Evaluate: Weigh up advantages, disadvantages, or suitability and reach a justified conclusion based on evidence (e.g., evaluating a meal plan for an older adult).