L1 - A Balanced Diet

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objectives

Define nutrition as taking in of nutrients for growth and tissue repair
Describe the role of fat as an energy storage substance
Describe the role of nutrients: carbs for energy, proteins for growth and repair, fats for storage, fibre to give bulk to undigested food and water to dissolve needed minerals around the body
Describe the structure of large molecules made from smaller basic units, i.e.

• simple sugars to starch and glycogen

• amino acids to proteins

• fatty acids and glycerol to fats and oils

Nutrition

Major Food Groups

Carbohydrates

Starchy foods contain carbohydrates which are made of long chains of identical small sugar molecules.

The long chains of carbohydrates are broken down into the smaller sugar molecules by the body.

The small molecules from carbohydrates are used by the body to release energy and make the body work.

Examples include: Sugar, Bread, Pasta, Rice, Potato and Wheat

Proteins

Proteins, like carbohydrates, are made of long chains of small molecules. In proteins, these small molecules are not identical.

Proteins are made up of chains of small molecules called amino acids. There are over 20 different kinds of amino acid.

Proteins are used by the body for growth and repair.

Examples of Proteins include Meat, Eggs, Fish Cheese and Milk.

Fats

Fats are made up of fat molecules which contain fatty acids and glycerol.

Fat molecules have to be broken down by the body so that they can be used for energy storage.

Fats are also used by the body to keep heat in and to make cell membranes.

Examples of Fats include Butter, Oils and Margarine.

Fibre

Fibers are the undigestible parts of plants that we consume.

Fibers are not digested but are used to help 'bulk' food in the digestive tract so that the muscles in the intestine can push the bulk out of the body.

We say that Fibers aid digestion.

Examples are Fresh fruit, Vegetables, Wholegrain cereal, Wholemeal bread, Beans and Brown rice.

Vitamins

Vitamins are needed to help the body work and help concentration.

Examples are found in Fresh fruit, Vegetables, Egg yolk, Fish, Cheese and milk.

Minerals

Minerals are needed to help the body work and help decision making.

Examples are found in Fresh fruit, Vegetables, Cheese and milk, Nuts Wholegrain and Wholewheat.

Calcium is a good example of a mineral that helps to strengthen bones

Iron is a good example of a mineral that is found in blood.

Water

Water is needed to stop the body dehydrating and maintain fluid levels

A Balanced Diet

This shows the correct proportion of each food you need.

A balanced diet contains food from all seven food groups in the correct proportions.

activity 1 - eat well plate

Complete the below worksheet to consolidate your learning:

Gamma-sheet.pptx

Food Labels

Food labels help us to understand how much of our foods consist of each food group.

Examples can be found below:

Activity 2 - food label question

One day a ten-year-old child ate a whole packet of the biscuits. The biscuits in the pack had a mass of 400 g.

How many grams of carbohydrate did the child eat? (2)

2. The amount of carbohydrate you calculated in part 1 was more than the UK guideline daily amount for the child. How much more? (1)

3. Give two possible health effects on the child of eating so many biscuits every day. (2)

Why do Different People require different amounts of energy from food?

It is all to do with something called metabolic rate.
Metabolic rate is the speed at which chemical reactions take place in the body
We need energy to fuel these chemical reactions!
Therefore, if there are more reactions taking place (for example, respiration) then we need more energy! So there will be a higher metabolic rate.

What factors affect metabolic rate?

Age
Gender
Inherited factors
Body size / weight
Exercise levels
Proportion of muscle to fat
Pregnancy

activity 3 - energy needs of different people

Scientists measured the amount of energy used by four people, A, B, C and D.

The scientists also measured the amount of energy taken in as food by each person. The chart shows the scientists’ results.

(i) What was the mean amount of energy used by D?

................................................................... kJ per day (1 mark)

(ii) The amount of energy used by D is different from the amounts of energy used by A, B and C.

Suggest two reasons why.

(b) The data in the bar chart was collected over twelve months.

Which person, A, B, C or D, would gain body mass over the twelve months? Give a reason for your answer.

(2 marks)

In the UK many people are obese. Doctors advise obese people to lose mass. Suggest two different ways an obese person could lose mass. (2 marks)

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