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Unlock This CourseYour body is like a complex machine that needs the right fuel to work properly. A balanced diet provides all the nutrients your body needs in the right amounts to grow, repair itself and stay healthy. Think of it like a recipe - you need all the right ingredients in the correct proportions to make something delicious!
Every day, your body uses energy for everything from breathing and thinking to running and playing sports. The food you eat provides this energy and the building blocks your body needs to maintain itself.
Key Definitions:
Your body needs seven different types of nutrients to stay healthy: carbohydrates, fats, proteins, vitamins, minerals, water and fibre. Each one has a special job to do and you need all of them working together like a team.
Macronutrients are the nutrients your body needs in large amounts. They provide energy and help your body grow and repair itself. The three macronutrients are carbohydrates, fats and proteins.
Carbohydrates are your body's preferred source of energy. They're like petrol for a car - they keep you going throughout the day. Your brain especially loves glucose, which comes from breaking down carbohydrates.
Quick energy from sugary foods like sweets, biscuits and fizzy drinks. They give you a fast energy boost but don't last long.
Slow-release energy from foods like bread, pasta, rice and potatoes. They keep you feeling full and energised for longer.
Found in wholemeal bread, vegetables and fruits. Helps your digestive system work properly and prevents constipation.
Many people think all fats are bad, but that's not true! Your body needs fats for energy, to absorb certain vitamins and to keep your cell membranes healthy. Fats provide more than twice as much energy per gram as carbohydrates.
Unsaturated fats (found in olive oil, nuts and fish) are good for your heart. Saturated fats (found in butter and fatty meat) should be eaten in moderation. Trans fats (in some processed foods) should be avoided.
Proteins are like the bricks and mortar of your body. They help you grow, repair damaged tissues and make important substances like enzymes and hormones. During your teenage years, you need extra protein because you're growing rapidly.
Proteins are made up of smaller units called amino acids. Your body can make some amino acids, but there are nine essential amino acids that must come from your food.
Complete proteins contain all nine essential amino acids. These come from animal sources like meat, fish, eggs and dairy. Incomplete proteins are missing one or more essential amino acids and come from plant sources like beans and nuts. Vegetarians can get complete proteins by combining different plant foods, like beans and rice.
Micronutrients are needed in much smaller amounts than macronutrients, but they're just as important. They include vitamins and minerals that help your body function properly.
Vitamins are organic compounds that help your body carry out essential processes. There are 13 vitamins your body needs and each one has specific jobs to do.
Found in citrus fruits and vegetables. Helps heal wounds, absorb iron and fight infections. Deficiency causes scurvy.
Made by your skin in sunlight and found in fatty fish. Essential for strong bones and teeth. Deficiency causes rickets in children.
Found in orange vegetables and dairy products. Important for good vision and healthy skin. Deficiency can cause night blindness.
Minerals are inorganic substances that help regulate body processes and build strong tissues. Your body needs different amounts of different minerals.
Calcium: Builds strong bones and teeth (found in dairy products). Iron: Makes red blood cells to carry oxygen (found in red meat and leafy greens). Sodium: Helps control water balance (found in salt).
Water makes up about 60% of your body weight and is involved in almost every body process. You can survive weeks without food, but only days without water!
Water helps transport nutrients around your body, removes waste products, regulates your temperature through sweating and cushions your organs. You need about 6-8 glasses of water per day, more if you're active or the weather is hot.
Fibre is the part of plant foods that your body can't digest. Even though you can't break it down, it's incredibly important for your health. Fibre helps food move through your digestive system, prevents constipation and may help prevent certain diseases.
Studies show that people who eat high-fibre diets have lower rates of heart disease, diabetes and bowel cancer. In countries where people eat traditional diets high in fibre (like rural Africa), these diseases are much less common than in Western countries where processed foods are more popular.
When you don't get enough of certain nutrients, your body can develop deficiency diseases. These were once common but are now rare in developed countries thanks to better nutrition knowledge and food fortification.
Caused by vitamin C deficiency. Symptoms include bleeding gums, loose teeth and slow wound healing. Prevented by eating fruits and vegetables.
Caused by vitamin D deficiency. Results in soft, weak bones that can become deformed. Prevented by sunlight exposure and vitamin D-rich foods.
Often caused by iron deficiency. Results in tiredness and weakness because your blood can't carry enough oxygen. Prevented by eating iron-rich foods.
A balanced diet doesn't mean you have to eat perfectly all the time. It's about getting the right balance over several days or weeks. The key is variety - eating many different types of foods ensures you get all the nutrients you need.
The UK government's Eatwell Guide shows the proportions of different food groups you should eat. It's like a plate divided into sections showing how much of your diet should come from each food group.
About one-third should be fruits and vegetables, one-third starchy carbohydrates, with smaller amounts of protein foods, dairy and minimal amounts of foods high in fat and sugar.
During adolescence, your body grows rapidly and your nutritional needs increase. Teenagers need more calories, protein, calcium and iron than adults. This is why it's especially important for young people to eat a balanced diet rather than surviving on junk food. Poor nutrition during these crucial years can affect growth, academic performance and long-term health.
Remember, a balanced diet is about making good choices most of the time, not being perfect. Understanding what your body needs helps you make informed decisions about what to eat, leading to better health, more energy and improved wellbeing throughout your life.