Carbohydrates Flashcards
Definition of carbohydrate
The major source of energy in the body
Are carbohydrates macronutrients?
Yes
What elements are carbohydrates formed from?
Carbon, hydrogen and oxygen
What are the 2 types of carbohydrate?
- simple carbohydrates (sugar)
* complex carbohydrates
What are the functions of carbohydrates in the diet? (4 things)
- provide body with energy for physical activity
- provide the body with energy to maintain bodily functions
- provide dietary fibre/ non-starch polysaccharide (NSP) to help digestion
- sugars sweeten and flavour foods
What does NSP stand for?
Non-starch polysaccharide
What are sugars?
- simple units that all carbohydrates are made from
What are the 2 types of simple sugars?
- monosaccharides
* disaccharides
What are monosaccharides?
Simple sugars
The simpler the carbohydrate, the more _____ it can be absorbed in the body and the ______ energy can be provided
- quickly
* faster
Name 3 monosaccharides
- glucose
- fructose
- galactose
Where is glucose found and what is it often used for?
- found in some fruits and veg
* often used by athletes in tablet or powder form to provide a fast energy boost
Where is fructose found and what is it used for?
- found in the juices of some fruits and plants, but mainly honey
- it is the sweetest of all sugars so manufactures can use a low amount but still provide the same level of sweetness as sucrose
How is galactose formed?
- during digestion of lactose (milk sugar)
What are disaccharides?
Double sugars that are made up of 2 monosaccharides
Name 3 disaccharides
- lactose
- maltose
- sucrose
Where is lactose found?
Found in milk
- some people think it gives milk a slightly sweet taste
How is maltose formed?
- formed from fermentation of cereal grains
Sucrose is the most common disaccharide, what is it also know as?
Sugar
What are the benefits of sucrose?
Provides body with energy, but has no other benefits in the diet. It contains no other nutrients
Where is sucrose found?
- sugar cane
What forms can you buy sucrose (sugar) in, give a few examples
- granulated sugar
- brown sugar
- caster sugar
- icing sugar
- sugar syrup
- treacle
What are the 2 forms of sugar?
- non-free sugar
* free sugar
What are non-free sugars?
Found naturally in the cells of fruits and vegetables, they are part of the cells
What are free sugars?
Sugar that you can see, such as cane sugar and those added to cakes, biscuits e.t.c
What are the most common problems relating to sucrose? (3)
- obesity
- tooth decay
- type 2 diabetes
Why are non-free sugars less harmful?
Easier for the body to absorb and less likely to lead to tooth decay
What are polysaccharides
Complex carbohydrates formed from hundreds of glucose molecules strung together. They provide the body with energy
- either starch or fibre
Does starch take longer for the body to digest than sugar? What benefits does this have?
- starches take longer than sugars for the body to digest
* so this provides a feeling of fullness for longer, helping to avoid overeating and obesity
Where do all starches come from?
Plant sources
How much should starchy foods make up our daily food?
Starchy foods should be 1/3 (one third) of our daily food
What are the functions of starch in the diet? (4 things)
- starch is broken down slowly into simple sugars by the digestive system to provide energy
- adds bulk to our diet
- gives a feeling of fullness (satiety)
- excess is converted to fat
What is starch broken down to in the digestive system
Simple sugars
What does the body do with excess starch?
Convert it into fat
Name some sources of starch …
Bread, rice, cereals, pasta and some fruit and veg
What happens if their is a deficiency of carbohydrates?
The body needs to have a constant supply of energy. If it does not have enough from carbohydrate foods it will use protein foods for energy.
Is deficiency of carbohydrates common in the UK?
No it is rare
What happens of we eat too much carbohydrates?
It is stored as fat
What health problems could too much carbohydrate lead to?
- cancer
- cardiovascular disease (CSV)
- coronary heart disease (CHD)
- diabetes
- dental problems
What is fibre/NSP and where is it found?
It is the non-digestible cellulose found in plant foods
NSP ____ be digested so it passes straight through the _______ ______, absorbing _____ and providing _____
- can’t
- digestive system
- moisture
- bulk
Dietary fibre definition
Material from plants, which is not digested by humans but which absorbs water and binds other residues in the intestine, thus aiding excretion of waste material from the body
What does dietary fibre do?
Helps to ‘push’ other food through the system and helps to ‘clean’ the walls of the intestine of bacteria.
Dietary fibre helps the efficient removal of _____ products from the body and it is vital to _____
- waste
* health
What is the recommended intake per day of fibre for 17 years and over (adults basically)?
30g/day
What are functions of dietary fibre?
- holds water and keeps the faeces soft and bulky
- helps prevent various bowel disorders, including: constipation, bowel cancer, diverticular disease, appendicitis ans haemorrhoids (piles)
- help people control their body weight because high fibre foods are filling
- high fibre diets are linked to lower blood cholesterol whilst reducing the risk of diabetes
Name some bowel disorders that dietary fibre helps to prevent
- constipation
- bowel cancer
- diverticular disease
- appendicitis
- haemorrhoids (piles)
Are high-fibre foods filling?
Yes
What health benefits do high-fibre diets have?
- lower blood cholesterol
* reduced risk of diabetes
What problems can happen with deficiency of fibre?
- constipation
* diverticular disease - where the lining of the intestine becomes distorted and inflamed
What happens in diverticular disease?
- lining of the intestine becomes distorted and inflamed
What are the 2 types of dietary fibre?
- insoluble
* soluble
What does insoluble fibre do?
It absorbs water and increases bulk, making the faeces very soft and bulky and easy to pass through the digestive system
Name some good sources of insoluble fibre?
- wholemeal flour
- wholegrain breakfast cereals and pasta
- brown rice
- some fruits and veg
What does soluble fibre do?
It slows down the digestion and absorption of carbohydrates and therefore helps to control blood sugar levels, which helps stop us feeling hungry
What health benefits may come with soluble fibre?
- reduced blood cholesterol
* reduced risk of heart disease
Name some good sources of soluble fibre
- oats
- peas, beans, lentils
- most types of fruit and veg
- vegetables and fruits provide more fibre if eaten with their skins on e.g potato and apple
Insoluble fibre definition
Absorbs water and increases bulk
Soluble fibre definition
Slows down digestion and absorption of carbohydrates
When we consume carbohydrates, our bodies convert the starch and sugar into what?
Glucose
How much energy in percentage is recommended to come from carbohydrates?
50%
