- 40 multiple choice
- Only what was talked about in class
- Close book
- Up until next Wednesday
- Macronutrients; give us energy
- Means hydrated carbon; consists of carbon hydrogen and oxygen; CHO means carbohydrate.
- Found in all plant foods and milk
- Also found in foods that are not found in the food groups
- Meat fish poultry and fats have no carbs
- Eggs and cheese have very little CHO.
- Made of sugar molecules
Types of carbohydrates
- Suffix –ose means sugar ( glucose, fructose, dextrose)
- Saccharide = sugar molecule (mono, di, poly)
Glucose: most abundant sugar in our diet; good energy source; found naturally
Fructose: sweetest sugar; found in fruit; found naturally
Galactose: does not occur alone in foods; binds with glucose to form lactose; not found alone in nature;
*often added to processed foods
Lactose: glucose + galactose (milk sugar)
Maltose: glucose + glucose (join in food to form starch; by product of fermentation of grains; beer and wine)
Sucrose: glucose + fructose ( found in sugar cane, and honey; table sugar), most common disaccharide.
- Storage form of carbs for plants
- Long strings of glucose
- Straight = amylose
- Branched = amylopectin
- Lots of starch in grains, potatoes, legumes
Endosperm: makes up 83% of kernel, energy storage, all starch
Bran: makes up 14%
Germ: makes up 3%
Fibre - Provide structure to the leaves, stems and seeds of plants
- Can’t be digested by humans
- Can be digested by the bacteria in the gut
- Often made of glucose but can be other monosaccharaides.
TYPES OF FIBRE Insoluble Fibre
Soluble fibre - Don’t absorb water
- Absorb water - Give stiff structure to plants
- Often used as gelling agents - Cellulose, hemicellulose, ligin
- Pectins, gums, mucilages - Found in whole grains, vegetables.
- High in oatmeal, prunes, barley, apples, legumes
Starts in the mouth; salivary amylase – salivary amylase breaks starch into glucose and smaller polysaccharides; not much happens in
Pancreatic amylase: Starch->glucose and maltose
Sucrose – sucrose -> glucose + fructose
Maltase – maltose -> glucose + glucose
Lactase – lactose -> glucose + galactose
Monosaccarides->intestinal cells->blood, then blood delievers them to the liver: all monosaccharides -> glucose.
- Glucose can be burned for energy or we can store it as glycogen.
- Animals store glucose as glycogen
- Fonud in liver and muscles
- Liver keeps blood glucose levels stable
- Muscles, fast energy for exercise
- Not a dietary source.
What do carbohydrates do?
- Provides the quickest source of fuel
- Glucose and glycogen provide energy for exercise
- The body regulates blood glucose levels closesly to make sure we have enough
- Spare protein
o If ur body is low on glucose protein can be turned into glucose vida gluconeogenesis
o Your body needs protein to make organs, muscle, skin, enzyemes, hormones, blood, everything.
o Your body will steal protein from blood, organs and muscle to make gluclose
- Prevents ketoacidosis
o If you eat too little cho your brain starts to starve
o You start making ketone bodies out of fat; your brain can burn these for energy but they are acids so they riase blood
acidity; too much acid can kill you
Low CHO diets
- Some involve ketosis to increase fat burning How much CHO do I need?
The DRIs – 130g to prevent ketosis
o One glass of milk, cereal, banana, a sandwhich,carrots
How much makes a healthy diet?
AMDRs: 45-65% of your calories should come from CHO
For a 2000 kcal diet: 45% of 2000 = 900kcal /4g per kcal
Are Carbs Healthy
Natural Sugars: found in raw foods; are in fruit (fructose, glucose and sucrose), milk and milk produces (lactose); these foods contain
fibre, vitamins and minerals; natural sugars are related to better health.
Added sugars: added during food processing, or at the table; table sugar (sucrose), high fructose corn syrup (fructose and glucose),
honey (fructose), molasses, glucose, dextrose.
- Empty calories; no nutrients associated with them
- High added sugar consumption is related to: a low quality diet (less vitamins and minerals), obesity, highblood cholesterol
levels, and low insulin sensitivity.
Less than 25% of kcals should come from sugar according to the DRI’s, while the World Health Organization says that less than 10%
of that should be from added sugars.
Sweeteners contain sugar alcohols and cyclamate (fake sugar); these upset the GI tract.
Aspartame: made of 2 amino acids and found in sugar free food
Acesulfame: in sugar free or diet products with other sweetners.
Sucralose (splenda): found in sugar free foods, it is safe.
Pros: great source of energy, needed by athletes for glycogen stores