Food, exercise and health · Grade 5
To stay healthy we need a balanced diet, regular exercise, good hygiene and enough sleep. A balanced diet has the right amounts of each food group, so we get all the nutrients we need: carbohydrates, proteins, fats, vitamins, minerals, fibre and water.
Key facts
- Food groups: fruit and vegetables; starchy foods (bread, rice, pasta, potatoes); proteins (meat, fish, eggs, beans); dairy (milk, cheese, yoghurt); and small amounts of oils and spreads.
- Carbohydrates and fats give us energy; proteins help us grow and repair the body; vitamins and minerals keep us healthy; fibre keeps food moving through the gut.
- Too little of a nutrient causes a deficiency disease: scurvy (vitamin C), rickets (vitamin D or calcium), anaemia (iron).
- Exercise makes the heart and muscles stronger. During exercise the heart beats faster to carry more oxygen to the muscles.
- Washing your hands with soap and water for at least 20 seconds removes germs and stops them spreading.
- Children need about 9 to 12 hours of sleep a night; teenagers need about 8 to 10.
- The energy in food is measured in kilojoules (kJ). Energy we take in but don’t use is stored as fat.
Worked examples
Example 1
A cereal bar has 420 kJ of energy. Walking uses about 15 kJ every minute. How long must you walk to use the energy in the bar?
Answer: 28 minutes