Carbohydrates

 Almost all of our carbohydrates come from PLANT food sources.  We get most of our carbohydrates from the GRAINS group.  FRUITS and VEGETABLES are also a good source of carbohydrates.

Carbohydrates The main function of carbohydrates is to PROVIDE ENERGY. End unit is glucose

5 Main Functions of Carbs Produce energy Store energy Build Macromolecules Spare proteins Spare fats (4 kcal/gram)

Carbohydrates are used most efficiently in the body for energy, so they are the preferred source of energy If carb intake is insufficient, the body will draw on proteins for energy Energy Production

Store Energy Excess glucose is stored as glycogen Stored in muscles and liver If we eat more carbs than our bodies need for energy, they get stored as FAT.

Build Macromolecules Small % is converted to ribose and deoxyribose (DNA, RNA and ATP)

Body can draw on proteins for energy, but it is less efficient when it does this – Proteins are harder to break down, taking more energy – The break down of proteins creates more waste By using carbohydrates, the body leaves proteins for building and maintaining cell structures Protein Sparing

Spares fats for other uses in the body Without carbs, the body can’t break down fats completely, which leads to ketosis (an increase in blood acidity, which causes cell and organ damage) Spare Fats

The three types of carbohydrates are: – SIMPLE SUGARS – COMPLEX STARCHES – FIBER

Sugars are SIMPLE. Starches are COMPLEX. Complex starches will BREAK DOWN into simple sugars.

SIMPLE SUGARS Food Sources:

Simple Sugars Monosaccharides- single sugar unit – Glucose (end unit of all carb breakdown) – Fructose (fruit sugar) – Galactose Quickest source of energy, digested rapidly!

Simple Sugars Disaccharides: 2 sugar units – Sucrose (table sugar) – Maltose (malt) – Lactose (milk sugar)

The different types of sugars and their food sources:

Simple and Complex Complex – Cereal – Apples – Beans – Grains – Oats – Green vegetables – Potatoes – Corn Simple Orange juice Milk Yogurt Honey Sugar Candy Soft drinks Jelly and Jams Corn Syrup

COMPLEX STARCHES Food Sources:

Complex Carbs Polysaccharides: many sugar units – Starch (plants) – Breads, cereals, corn, potatoes, and legumes Provide a steady supply of sugar needed for energy

How Your Body Uses Carbs Broken down in digestive tract to monosaccharides Monosaccharides pass through the intestine into the bloodstream and on to the liver, where sucrose and galactose are converted to glucose When the amount of glucose in the blood rises, the body releases insulin from the pancreas

Insulin helps trigger body cells to burn glucose for energy, thereby reducing the amount of glucose in the body (reducing blood sugar levels) Insulin also causes muscles and the liver to store glucose not used as energy Insulin

Glycogen is the body’s storage form of glucose If cells do not have an immediate need for the glucose they took from the bloodstream, they convert it to glycogen to be used later – Glycogen is stored in the muscles (2/3) and in the liver (1/3) – Glycogen in the muscles is converted back into glucose when energy is needed Glycogen

The liver only stores a limited supply of glycogen If more carbs are eaten than the liver can convert to glycogen and store, the excess is converted to fat and stored in fatty tissue in the body Fat stored cannot be converted back into glucose *Using Carbs Liver Storage of Glycogen

Choosing the Best Form of Carbohydrate Carbs to LimitSmarter CarbsBest Choices Instead of:Choose:Or better yet choose: CandyDried fruitWhole fruit Soda or punchFruit juiceSeltzer with a dash of juice White breadWhole-wheat breadSeven-grain bread Enriched pastaWhole-wheat pastaCracked wheat pilaf White crackersWhole-grain crackerVegetable sticks Cotton candyCaramel appleApple Chocolate chip cookieOatmeal raisin cookieStrawberries Sugary cerealBran cerealRolled oats