Health and disease, Year 7: more practice

The right amounts of all the nutrients, plus fibre and water

提示Think about all of them, not just one.

为什么A balanced diet gives enough of each nutrient for energy, growth and repair without too much or too little.

It has too much fat and sugar and too little protein, vitamins and fibre

提示Think about what is in excess and what is missing.

为什么A balanced meal needs a mix of food groups. This one is high in energy but low in several nutrients the body needs.

They provide vitamins, minerals and fibre

提示Think about what fresh produce contains besides sugar.

为什么Fruit and vegetables supply vitamins and minerals that keep the body working, plus fibre to keep the gut moving.

Obesity

提示Unused energy is stored.

为什么The extra energy is stored as body fat. Obesity raises the risk of heart disease and type 2 diabetes.

Fat

提示Think of blubber.

为什么Fat stores more energy gram for gram than carbohydrate, and a layer under the skin reduces heat loss.

Calcium

提示Milk and cheese are rich in it.

为什么Calcium makes bones and teeth hard. Good sources include milk, cheese and green leafy vegetables.

An egg

提示Protein is used for growth and repair.

为什么Eggs, meat, fish, beans and dairy foods are rich in protein.

Bacteria

提示These are single-celled microbes without a nucleus.

为什么Bacteria feed on the sugar in milk and make lactic acid. This makes the milk thicken and taste sour.

A fungus (a mould)

提示Alexander Fleming noticed it growing on a petri dish.

为什么Penicillin comes from a mould called Penicillium. It kills bacteria but does not work on viruses.

Most are harmless or useful

提示Think of how many microbes there are compared with the number that cause disease.

为什么Only a small proportion of microbes cause disease. Many live safely on and in us, or are used to make food and medicines.