What are Carbs?

What are Carbs?Nutrients required by the body.

1What do we want to know?What are they?Why do we need them?Are there different types?What are the best type to eat?What does GI stand for?

CarbohydratesFormed from the word carbo (meaning carbon) and hydrate (meaning water)Made up of carbon, hydrogen and oxygen molecules (carbon and water)Produced by plants through photosynthesis

But most importantly:

Photosynthesis is a process in which green plants use energy from the sun to transform water, carbon dioxide, and minerals into oxygen and organic compounds. It is one example of how people and plants are dependent on each other in sustaining life.

3CARBOHYDRATESProvide the Body with ENERGY

They are one of the macronutrients needed by the body in order to function properly.

Not only do Carbohydrates provide energy and heat for metabolism and activity, they also: Regulate bowel movement (dietary fibre) Are Essential for brain function Regulate the use of fats and proteins Reserve proteins for primary function Glucose is the fuel of choice for active muscles as it provides heat and energy To the body

Why else do we need carbs?How does it give us ENERGY?When we eat, the body breaks down the carbohydrates to make glucose which is then absorbed into the bloodstreamGlucose = Fuel for our Bodies (1g CHO =16kJ)

A lot of carbohydrates also contain vitamins and minerals that help keep us in tip-top shape and health

There are 3 types of Carbohydrates:

MonosaccharideSimpleDisaccharideDoublePolysaccharideComplexGlucose fruit (grapes)Fructose honey & fruitsGalactose when milk is digestedSucrose sugar caneMaltose cerealsLactose - milkStarch fruits, vegies, cerealsDextrin formed from starch (when bread is toasted)Pectin fruit (apples & citrus fruits) also known as hemi-celluloseCellulose fibre in plantsGlycogen glucose stored in liver and musclesSimple CarbohydratesHave short chains of molecules so dissolve quicklyEg. glucose, fructose, galactoseFoods include:CakesHoneySoftdrinkSyrupsLolliesSugarJelliesSome fruits (grapes)

Glucose fruit (grapes), Fructose honey and fruits, Galactose when milk is digested

8Disaccharides (Double)When you have a joining of 2 monosaccharides

Eg. Sucrose, Maltose, LactoseFoods Include:Sugar caneCerealsMilk

Complex CarbohydratesHave Long Chains of molecules and take longer to dissolveEg. starch, dextrin, pectin, cellulose, glycogenFoods include:PastaBreadGrains/CerealsFruits and vegetables

How much do we need?Medical experts say that 45 - 60% of our diet should be made up of carbohydratesAverage intake for a teenager should be about 8700 kilojoules per day

So, 8700 x 60 % = 5220 kilojoules

1 gram of carbohydrates = 16 kilojoules

So, the RDI (Recommended Daily Intake) is approximately 310g of carbohydrates per dayShow some examples of food packets with the carbohydrate serve shown on the label11ExcessDeficiency Overweight & obesity because excess glucose in the body is stored as fat Diabetes (excess sugar in the blood)

Weight loss Starvation Fatigue ConstipationToo much or not enough?

How do I get enough?To help get the right amount of carbohydrates in your diet, try to include 2 serves at each meal.

An example of a serve is:2 slices of bread1 cup cooked rice1 1/3 cups cereal1 medium piece of fruit1 tub of low fat yoghurt250ml glass low fat milk

Remember, a balanced diet is a healthy diet!!!

How do I know how many carbohydrates a food contains?There is lots of information around: in books, on the internet, health practitionersAll packaged foods must have labels to let us know what they contain

Lets have a look at a few common foods and thecarbohydrates they contain

Basic FoodsFoodServing sizeCarbohydratesPotato (boiled)1 medium33gHoney1 tablespoon17gIce cream (soft serve)1 cup22gCorn Flakes1 cup24gApple1 medium19gBanana1 medium27gGrapes1 cup16gOrange Juice1 cup33gSpaghetti1 cup40gBread1 slice16gWe could use Food Composition tables to analyse our diets.What is GI?A ranking given to food that describes how quickly the carbohydrates they contain will be digested (changed to glucose) and absorbed into our bodiesCalled the GLYCAEMIC INDEX

High GI foods are digested and absorbed quicklyLow GI foods are digested and absorbed slowlyLow Vs HighKeep you feeling full for longer as they provide a gradual supply of energyHelps keep blood glucose levels stableMay help to prevent some diseasesUsed when high energy levels are needed for shorter bursts Eg. athletes, sports people body buildersLow GI FoodsHigh GI Foods

Low GI FoodsHigh GI FoodsWholegrain breadPastaOatsApples, apricots and orangesYoghurt and milkDried beansLentilsKidney beansRolled oatsWhite and wholemeal breadProcessed cerealsShort grain ricePotatoMost cracker biscuitsWatermelonLollies, cakes etc

Dietary FibreAnother kind of CarbohydrateAs if the humble Carbohydrate didnt already have a big enough job!!!!It also provides our diet with fibre a carbohydrate that only comes from plant based foods (fruits, vegetables and grains)Fibre in food is tough and stringy and our bodies wont break it down completely so it helps to regulate us

RDI of Fibre is 25 30g

Best Fibre options:Wholemeal or Grain Breads, Bran, Fruit and Vegetables, nuts, seeds, popcorn

Functions of Dietary FibreStimulates chewing and encourages saliva flow to ensure healthy gums and teeth and more efficient digestionInhibits the emptying process of the stomach, therefore satisfying hunger for longerControls the rate of glucose absorption into the blood by slowing down the digestion of nutrientsSoftens faecal waste to ensure comfortable bowel actionsCooking with CarbohydratesSugarsStarchAs a sweetener.As a preservativeIt provides food for yeast in bread making.In cake making, it helps the fat to entrap air, making cakes light.It colours food.Confectionery and sweetsCake decorating, icings and fillings.It softens gluten in cake making, creating a lighter product.Syrups and glazes.Meringues it strengthens the protein in egg white, helping the mixture to retain air.As a thickener in sauces, soups and gravies.Found in cereals e.g. wheat may be used in baking bread, cakes, etc.Found in root vegetables and potatoes.Found in foods such as pasta, bread and rice, and forms the basis of a main meal.Starch is hygroscopic; it absorbs moisture from the air and is added to baking powder to keep it dry.PectinPectin found in ripe fruit helps to set jams and jellies.Effects of dry and moist cookery methodsDry heat of sugar causes caramelisation.When boiled, sugar dissolves in water and then becomes a syrup. As water evaporates it caramelises and eventually burns.Starch dissolves, swells and bursts when heated in water/liquids.Dry heat causes starch cells to burst e.g. popcorn, pastry.When dry heat is applied to starch shorter chain polysaccharides are formed, these are called dextrins (toasting).

SummaryCarbohydrates:provide the body with ENERGYgood source of fibregood source of vitamins3 different types:Monosaccharide (simple/sugar)Disaccharide (double)Polysaccharide (complex/starch)The Glycaemic Index tells us how long the energy from carbohydrates will stay in our body