WHAT ARE CARBS?

Nutrients required by the body.

What 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?

Carbohydrates

Formed 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:

CARBOHYDRATES

Provide 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 bloodstream

Glucose = 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:Monosaccharide

SimpleDisaccharide

DoublePolysaccharide

Complex

Glucose – fruit (grapes)

Fructose – honey & fruits

Galactose – when milk is digested

Sucrose – sugar cane

Maltose – cereals Lactose - milk

Starch – fruits, vegies, cereals

Dextrin – formed from starch (when bread is toasted)

Pectin – fruit (apples & citrus fruits) also known as hemi-cellulose

Cellulose – fibre in plants

Glycogen – glucose stored in liver

and muscles

Simple Carbohydrates

Have short chains of molecules so dissolve quickly

Eg. glucose, fructose, galactoseFoods include:Cakes HoneySoftdrink SyrupsLollies SugarJelliesSome fruits (grapes)

Disaccharides (Double)

When you have a joining of 2 monosaccharides

Eg. Sucrose, Maltose, LactoseFoods Include:Sugar caneCerealsMilk

Complex Carbohydrates

Have Long Chains of molecules and take longer to dissolve

Eg. starch, dextrin, pectin, cellulose, glycogen

Foods include:PastaBreadGrains/CerealsFruits and vegetables

How much do we need?

Medical experts say that 45 - 60% of our diet should be made up of carbohydrates

Average 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 day

Excess Deficiency

• Overweight & obesity because excess glucose in the body is stored as fat• Diabetes (excess sugar in the blood)

• Weight loss• Starvation• Fatigue• Constipation

Too 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 bread

1 cup cooked rice

1 1/3 cups cereal

1 medium piece of fruit

1 tub of low fat yoghurt

250ml 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 practitioners

All packaged foods must have labels to let us know what they contain

Let’s have a look at a few common foods and thecarbohydrates they contain

Basic Foods

Food Serving size Carbohydrates

Potato (boiled) 1 medium 33g

Honey 1 tablespoon 17g

Ice cream (soft serve) 1 cup 22g

Corn Flakes 1 cup 24g

Apple 1 medium 19g

Banana 1 medium 27g

Grapes 1 cup 16g

Orange Juice 1 cup 33g

Spaghetti 1 cup 40g

Bread 1 slice 16g

We 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 bodies

Called the GLYCAEMIC INDEX

High GI foods are digested and absorbed quickly

Low GI foods are digested and absorbed slowly

Low V’s High

Keep you feeling full for longer as they provide a gradual supply of energy

Helps keep blood glucose levels stable

May help to prevent some diseases

Used when high energy levels are needed for shorter bursts

Eg. athletes, sports people

body builders

Low GI Foods High GI Foods

Low GI Foods High GI Foods

Wholegrain breadPastaOats

Apples, apricots and oranges

Yoghurt and milkDried beans

LentilsKidney beansRolled oats

White and wholemeal bread

Processed cerealsShort grain rice

PotatoMost cracker biscuits

WatermelonLollies, cakes etc

Dietary FibreAnother kind of Carbohydrate

As if the humble Carbohydrate didn’t 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 won’t 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 Fibre

Stimulates chewing and encourages saliva flow to ensure healthy gums and teeth and more efficient digestion

Inhibits the emptying process of the stomach, therefore satisfying hunger for longer

Controls the rate of glucose absorption into the blood by slowing down the digestion of nutrients

Softens faecal waste to ensure comfortable bowel actions

Cooking with Carbohydrates

Sugars Starch As a sweetener. As a preservative It 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 sweets Cake 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.

Pectin Pectin found in ripe fruit helps to set jams and jellies.

Effects of dry and moist cookery methods

Dry 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).

Summary

Carbohydrates: provide the body with ENERGY good source of fibre good source of vitamins 3 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