Carbohydrates Flashcards
Are carbohydrates macro nutrients or micro nutrients?
Macro nutrients
What chemical compounds are carbohydrates made from?
CHO (carbon, hydrogen, oxygen)
What are the 2 types of carbohydrates?
1) Sugar - simple carbs
2) Complex carbohydrates
What are the functions of carbohydrates in the diet?
- Provide body with energy for physical activity
- Provide body with energy to maintain bodily functions
- Provide NSP (fibres) for digestion
- Sugars sweeten and flavour foods
What are the 2 types of simple carbohydrates?
Monosaccharides
Disaccharides
What is the difference between monosaccharides and disaccharides?
Monosaccharides are one unit whereas disaccharides are 2 monosaccharides
Give 3 examples of monosaccharides and their functions.
Glucose - simple sugar molecule
Fructose - sugar found it fruits and plants
Galactose - formed during digestion of lactose (milk sugar)
Give 3 examples of disaccharides and their functions.
Lactose - milk sugar
Maltose - result of fermentation of cereal grains
Sucrose - known as ‘sugar’, contains no other nutrients and its function is to provide energy in the diet. - Comes from sugar beet or cane
What are the sources of free and non-free sugars?
Non-free - cells in fruits and vegetables
Free sugars - cakes sweets etc.
What is glycaemic index?
How quickly carbohydrates affect blood sugar levels.
What does it mean when a food has a high glycaemic index?
Those foods are digested quickly by the body and cause a rise in blood sugar levels.
What does it mean when a food has a low glycaemic index?
They are digested slowly and give slow energy release, usually these foods are wholemeal and are complex carbs.
- Gradual rise in blood sugar levels
What are complex carbohydrates?
- Polysaccharides formed from many glucose units.
What nutrients do starchy foods contain?
- B-Vitamins
- Iron
- Calcium
What are the differences between starches and sugars?
Starches take longer to digest than sugars and give a fuller feeling ensuring that obesity is avoided as you eat less.
What are the sources of starches?
Plant sources - grain, fruit and veg etc.
What proportion of the diet should be made up of starchy carbohydrates?
1/3
What are the functions of starch in the diet?
- Provide energy (broken down into simple sugars in the digestive system)
- Adds bulk to the diet
- Gives feeling of fullness
- Excess converted to fat
What is dietary fibre?
Otherwise known as NSP (non-starch polysaccharide), it is non-digestible cellulose found in plant.
What happens to dietary fibre in the body?
- Passes through the digestive system, absorbs moisture and provides bulk
- Pushes other food through the system and cleans intestine wall of bacteria.
For 2-5, 6-10, 11-16, 17+ what are the recommended daily intakes?
15, 20, 25, 30g
What are the functions of dietary fibre?
- Holds water keeping faeces soft and bulky
- Helps prevent bowel disorders (constipation, bowel cancer, diverticular disease, appendicitis and haemorrhoids (piles))
- Helps body weight control as high fibre food is filling
- High fibre diets lower cholesterol levels and prevent diabetes
What is the difference between soluble and insoluble fibres?
Insoluble - absorb water, increase bulk making the faeces soft and easy to excrete
Soluble - slow down digestion and carb absorption, controlling blood sugar levels giving you a feeling of satiety.
What are the consequences of excess carbohydrate consumption?
- Obesity, diabetes as extra carbs are fat
- If sugar not used > stored as fat
- Sugary foods > tooth decay (dental caries)
- Rise in blood sugar levels - type 2 diabetes
What are the consequences of deficiency of carbohydrates?
- Drop in blood sugar levels
- Causes hunger, dizziness, nausea, tiredness, energy loss
- If no energy, protein used weakening muscles.
