Carbohydrates A macronutrient

Carbohydrate facts Eating one gram of CHO provides the body with 16 kilojoules of energy 55% of our energy should come from complex carbohydrates such as wholegrain cereals, fruit and vegetables. Complex CHO assist with digestion and help with disease prevention

Carbohydrate facts Eating complex CHO will allow your metabolism to increase, which will assist in burning kilojoules If CHO are not used, they are mostly converted and stored as fat or converted into glycogen (stored inside muscle and liver) ready to boost blood sugar levels should they drop during the day.

Carbohydrate groups There are two main groups of CHO: 1. simple sugars (monosaccharides) From honey, fruit & vegetables An example of a simple sugar is glucose (most soluble, easily absorbed CHO)

Carbohydrate groups 2. complex CHO (polysaccharides) From wholegrain cereals, fruit and vegetables (raw and skin), nuts, legumes Examples of complex CHO are starch and fibre

Dietary fibre There are two types of fibre – 1. insoluble fibre is found in the structural parts of plant cell walls … fruits, vegetables, nuts and wholegrain products has an important role in preventing constipation by producing softer bulkier faeces

Dietary fibre 2. soluble fibre Is found mainly in plant cells … fruits, vegetables, lentils and cereals Soluble fibre can be important to help lower LDL (‘bad’) cholesterol levels by binding and excreting these molecules Soluble fibre can also delay blood glucose absorption; thus regulating blood glucose levels.

Functions of carbohydrate Carbohydrates are a major source of energy They can be used very efficiently by the body, especially systems such as the central nervous system

Functions of carbohydrate Eating cellulose (from polysaccharides) provides the body with fibre or roughage, to speed up the metabolism and prevent constipation

Functions of carbohydrate Fibre can therefore be a preventative/protective factor against dietary diseases such as heart disease, bowel cancer, obesity and diabetes

Food sources Cereals and cereal products Pasta Rice Fruit Vegetables Legumes, nuts and lentils Sugar, jam, honey

Glycaemic index (GI) Glycaemic index (GI) ranks foods according to the average time taken to reach peak blood glucose levels. Foods are given a score out of 100 and are ranked as follows: Low GI foods (less than 55) are digested and absorbed slowly, releasing CHO gradually (baked beans, porridge, lentils) Medium GI foods (55–70) provide an average release of CHO (chocolate, orange juice, oats) High GI foods (greater than 70) provide a quick energy source (jelly beans, dry biscuits)

Glycaemic index (GI) Source: www.nickfitness.com/glycemic_index

Glycaemic index (GI) Glycaemic index is especially useful for people with diabetes who require a slow release of glucose into the bloodstream. Individuals with diabetes do not secrete any or enough insulin to move glucose from the bloodstream and into the cells for absorption. Low GI foods aid in slowing the release of glucose into the bloodstream, enabling diabetes sufferers to better manage their glucose levels.

Glucose absorption This is a diagram of how carbohydrates (glucose) are absorbed in the body of healthy people. Image source: whittier.org