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 are made up of carbon, hydrogen and oxygen

Carbohydrates Provide 50% of the total energy intake with no more than 11% from sugars

Carbohydrates During 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

(non-starch polysaccharides) 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

Starches Slow 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

Which type of GI is better for us? 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