Key Stage 3 design and technology · Cooking and nutrition

KS3 design and technology: nutrition and healthy eating

In Years 7 to 9, food lessons go beyond “eat your five a day” to explain what nutrients do in the body, why different people need different things and how to read a food label. Pupils are taught to understand and apply the principles of nutrition and health, and to use that understanding when they plan, cook and judge their own dishes.

Nutrition and healthy eating, explained

Pupils learn that food supplies nutrients, which fall into two groups. The macronutrients are needed in large amounts: carbohydrate, mainly for energy, protein, for growth and repair, and fat, a concentrated source of energy that also carries some vitamins. Weight for weight, fat gives more than twice the energy of carbohydrate or protein, which is why fatty foods are energy-dense. The micronutrients, vitamins and minerals, are needed in tiny amounts but matter a great deal: calcium for bones and teeth, iron to make the haemoglobin that carries oxygen in the blood, and vitamin C to help the body absorb iron from plant foods. Fibre keeps the digestive system working, and water is essential.

A balanced diet means getting the right nutrients, in the right amounts, over days and weeks, not perfection at every meal. Schools usually teach the government’s healthy eating guide, shown as a plate or a set of food groups: plenty of fruit and vegetables, starchy foods (preferably wholegrain), some dairy or alternatives, some protein foods such as beans, pulses, fish, eggs and meat, and only small amounts of foods high in fat, salt and sugar. Pupils compare this with real meals and suggest improvements. Good lessons treat food as neither good nor bad, and avoid dieting or body-image talk. The focus is on health, energy and enjoyment.

Nutritional needs change with age, activity and circumstances. Teenagers grow quickly, so they need extra energy, calcium for bone growth and iron, especially girls once periods begin. Vegetarians and vegans need to plan for protein, iron and, for vegans, vitamin B12, which has to come from fortified foods or a supplement. People with allergies, such as to nuts or milk, or with coeliac disease, must avoid particular ingredients. Pupils also learn how cooking changes food. For example, vitamins B and C dissolve in cooking water, so steaming or using less water keeps more of them.

Reading food labels is a practical skill. The nutrition table gives amounts per 100 g, and often per portion, and the front-of-pack colours show whether fat, saturated fat, sugars and salt are low (green), medium (amber) or high (red). Pupils also meet the idea that sugar appears under many names, and that honey, syrups and fruit juice count as free sugars. The curriculum then asks pupils to apply what they know, so they judge a menu or a recipe and adapt it to improve the balance, and use these principles when cooking.

Words your child will hear

Nutrient: A substance in food that the body uses, such as protein, carbohydrate, fat, vitamins and minerals.
Balanced diet: Eating a variety of foods that provide the right nutrients and energy for a person’s needs.
Protein: The nutrient used for growth and repair, found in meat, fish, eggs, dairy, beans and pulses.
Fibre: The part of plant foods the body can’t digest, which keeps the gut healthy.
Free sugars: Sugars added to food or drinks, plus those in honey, syrups and fruit juices.
Energy density: How much energy a food gives for its weight. Fatty foods have a high energy density.
Dietary need: A reason someone eats a particular way, such as an allergy, religion or ethical belief.

What the National Curriculum says

The programme of study for Key Stage 3 says:

Pupils should be taught to understand and apply the principles of nutrition and health
As part of their work with food, pupils should be taught how to cook and apply the principles of nutrition and healthy eating.

Objectives from the National Curriculum in England, © Crown copyright, used under the Open Government Licence v3.0.

Try it: improving a packed lunch

A Year 9 pupil’s packed lunch is a cheese sandwich on white bread, a bag of crisps, a chocolate flapjack-style bar and a fizzy drink. A label on the bar shows 28 g of sugars per 100 g. How could the lunch be improved, using nutrition principles?

Sort the foods into groups. Sandwich: starchy food and dairy. Crisps: made from potato, but high in fat and salt, so they belong with the foods to eat less often. Bar and drink: mostly sugars. There is no fruit or vegetable, little fibre and no real source of protein beyond the cheese.
Check the label. For sugars, more than 22.5 g per 100 g counts as high (red). At 28 g per 100 g, the bar is red. The drink, if it contains sugar, will add to a total that is already high.
Suggest swaps that keep the lunch enjoyable. Use wholemeal or seeded bread for more fibre, and add salad such as cucumber or tomato in the sandwich. Replace the crisps with a piece of fruit or a handful of unsalted nuts, if nuts are allowed at school. Swap the fizzy drink for water or milk, which also supplies calcium.
Check that the lunch still gives enough energy for an active teenager. It should not become so small that the pupil is hungry all afternoon. Adding a yoghurt or a boiled egg helps with protein.
Explain the reasons, not just the changes. Fibre and wholegrain help the gut and keep the pupil full for longer, calcium supports growing bones, and less free sugar is better for teeth and for health overall.

A good answer names the food groups missing, uses the label evidence (28 g sugars per 100 g is red), gives specific swaps with a nutritional reason for each, and checks that the lunch still has enough energy and still appeals to the person eating it.

Common mistakes and how to help

Fat (or carbohydrate) is bad and should be avoided

Headlines and diet trends often single out one nutrient, so children begin to think of whole nutrients as enemies.

What helps: Every macronutrient does a job. The question is the type and the amount: unsaturated fats from fish, nuts and oils are useful, and wholegrain carbohydrates are a main energy source. Talk about balance across the day.

Natural sugars, such as honey or fruit juice, are healthy sugars

Natural sounds better than added, and the foods feel wholesome.

What helps: Honey, syrups and fruit juice count as free sugars, which the body treats like any other. Whole fruit is different because its sugars are held within the structure of the fruit, along with fibre. Check the label rather than the front of the packet.

A red traffic light means the food should never be eaten

Colours feel like instructions, and the figures are per 100 g, not for what is actually eaten.

What helps: Colours are a guide to compare similar foods. Grated cheese or olive oil can be red for fat but are used in small amounts. Look at portion size and how often the food is eaten.

Teenagers need protein supplements to be fit and strong

Adverts and social media make shakes and bars look essential.

What helps: Most young people get enough protein from ordinary food. Meals with meat, fish, eggs, dairy, beans or lentils provide it. If a teenager is thinking of changing their diet in a big way, speak to a doctor or school nurse first.

How to help at home

Label detective. Next time you shop, let your child compare two similar products, such as two breakfast cereals or two yoghurts, using the per 100 g figures. Ask which has more sugar, fibre or salt, and whether the difference would matter for how you use it.
Plate check. At a family meal, ask your child to tick off the food groups on the plate. If one is missing, how could a snack or tomorrow’s meal fill the gap? Keep the tone curious, not critical.
Plan a day of meals. Hand over the planning of one day’s food, with breakfast, lunch, dinner and a snack, for a particular person, such as a vegetarian cousin or a grandparent who needs more calcium. They explain their choices in terms of nutrients.
Talk about food kindly. Avoid labelling foods good or bad, and avoid talk of dieting or weight. Describe food as fuel, enjoyment and a way to look after growing bodies. If you worry about your teenager’s eating, a GP is the right first call.

Builds on

Key Stage 2: Healthy and varied diet
Key Stage 2: Cooking savoury dishes
Key Stage 2: Seasonal food
Key Stage 2: Grown, reared, caught, processed