Science 8th grade
UNIT 2: Food and digestion 2.2 A balanced diet
Science 8th grade
UNIT 2: Food and digestion 2.2 A balanced diet
Your diet is the food that you eat cach day. Your diet should provide you with enough of cach kind of nutrient. It should also give you the right amount of energy.
A dict that provides all the different kinds of nutrients, and the right amount of energy, is called a balanced diet.
Nutritional deficiencies
If a person does not eat enough of a particular nutrient, their body may not be able to work properly. They may have a nutritional deficiency disease.
For example, a child who does not have enough protein in her body may not be able to make enough new cells. She will not grow properly.
The table shows information about two vitamins and two minerals, and the deficiency discases that develop if they are lacking in the diet.
This photograph shows approximately how much of your diet should be made up of each of the five food groups.
| disease Deficiency | Function in the body | Good sources | Example | Nutrient |
| scurvy - the skin becomes weak, so sores develop | helps to make strong skin | citrus fruits | vitamin C | vitamins |
| rickets - the bones are weak, so the legs may become bent | needed to make bones and teeth | dairy products | vitamin D | |
| anaemia - the blood cannot carry enough oxygen, and the person feels very tired | needed to make haemoglobin, which carries oxygen in the blood | red meat, dark green vegetables | iron | minerals |
| the bones and teeth become weak | needed to make bones and teeth | dairy products, fish | calcium |
Not too much
There are some nutrients that you should avoid cating too much of. Too much sugar can make your teeth decay. Too much fat in the diet can increase the risk of developing heart disease when you are older
Eating too much fat and carbohydrate may mean that you take in more energy each day than you use. The body stores these extra nutrients as fat. Everyone needs some fat stores, but it is not good to have too much. Being seriously overweight can cause damage to joints, and increase the risk of developing heart disease and diabetes.
What should I eat?
These students are giving some good guidelines for eating a balanced diet.
Question
1) The sentences below are reasons for the pieces of advice the students are giving Match each reason with the piece of advice.
a: This means you will get some of each kind of nutrient, including the different vitamins and minerals.
b: These contain fibre and lots of vitamins.
c: This often contains a lot of fat, and very few vitamins or minerals.
It is fine to eat some of it, as long as you eat plenty of other kinds of foods as well.
d: Not eating enough food will prevent the cells, tissues and organs in your body having enough energy to keep healthy.
e: When you get older, it can increase your risk of getting heart disease or diabetes.