Carbohydrates

Carbohydrates

To learn the importance of Carbohydrates in the diet

To learn about the three groups of Carbohydrates

To learn about the main food sources of Carbohydrates

Carbohydrates

Carbohydrates are made up of carbon, hydrogen and oxygen

Carbohydrates

Provide 50% of the total energy intake with no more

than 11% from sugars

CarbohydratesDuring digestion carbohydrates are

changed to Glucose, which is used for energy.

Excess glucose is stored in the liver as

Glycogen and can be used when extra energy is needed.

If it is not used it is stored as Body Fat

Carbohydrates

Are divided into three main groups:

Sugars

Starches

NSP (non-starch polysaccharides)

Sugars

Intrinsic Sugars are contained in the structure of foods such as fruits and vegetables.

Fructose – honey and fruit

Glucose – ripe fruits

Lactose – milk and milk products

Sugars

Extrinsic Sugars

are not part of the cell structure of plants

BUT are added to foods to provide sweetness.

Sucrose obtained by refining sugar cane/beet

Used in recipes or added to drinks

Sugars

No food value other than providing a quick source of energy.

Sometimes called ‘empty calories’ or ‘quick fix’ energy.

Starches

Polysaccharide made up of long chains of glucose units.

It is partly digested in the mouth and changed in the small intestine to glucose.

Takes longer to digest than Sugar and so

releases ENERGY SLOWLY

StarchesSlow Releasing Energy

Good food sources are cereals, wholegrain breads, root vegetables, pulses, bananas, rice and pasta

NSP (non-starch polysaccharide)

This is also known as Dietary Fibre.

Humans cannot digest dietary fibre, but it is important to move waste material in the large intestine.

NSP (non-starch polysaccharide)

Helps to control blood sugar levels

Makes us feel fuller for longer and

prevents us from snacking

Glycaemic Index

Glycaemic Index (GI) is a measure of the effects of carbohydrates on blood glucose levels.

Carbohydrates that break down quickly during digestion and release glucose rapidly have a HIGH GI.

Carbohydrates that break down slowly during digestion and release glucose slowly have a LOW GI.

Glycaemic Index

Suggest some foods that have a HIGH GI

Suggest some foods that have a LOW GI

Glycaemic Index

Which type of GI is better for us?

Why?

Recap Questions

Why do we need carbohydrates in our diet?What are the three groups of carbohydrates?What is the difference between intrinsic and

extrinsic sugars?What is dietary fibre?Why is it important in our diets?List the foods that are good sources of dietary fibre