Download CARBOHYDRATES

CARBOHYDRATES
Not the evil we’re led to believe
What are carbohydrates?
Carbo-hydrate means carbon and water
(C + H2O). For every carbon there is 1
water molecule or 2 hydrogen atoms and
1 oxygen atom.
 2 categories:

Simple carbohydrates =
 Complex carbohydrates =

Where do carbohydrates come
from?
Plants and photosynthesis
 Except for galactose, which comes from
milk

Carbohydrates

Sugars (saccharides

Monosaccharides (single sugars – one
molecule)
Glucose – the basic fuel for our bodies
 Fructose – found in fruit
 Galactose – found in milk


Why is it better to ingest sugar in fruits
than as refined sugar?
Carbohydrates

Sugars cont’d

Disaccharides (two sugars joined together)
Sucrose – glucose + fructose, table sugar &
honey.
 Maltose – glucose + glucose, found in grains.
 Lactose – glucose + galactose, found in milk.

Carbohydrates

Polysaccharides (means many sugars or
3 or more sugars)
Complex Carbohydrates
 Fiber –

Soluble fiber – dissolves in water and is
digestable.
 Insoluble fiber – does not dissolve in water, less
digestable

Carbohydrates used by Man

Polysacchrides cont’d
Fiber –
 Soluble fiber – dissolves in water and is
digestable.


Insoluble fiber – does not dissolve in water, less
digestable.
Do we really need
carbohydrates?
Glucose is the preferred fuel for many of
our cells including our brain and the rest
of the nervous system.
 Carbohydrates (includes fiber) often
occur in food (fruits and vegetables) with
water, vitamins, minerals,
phytochemicals, and no fat. They are
also relatively cheap!

Do we really need
carbohydrates?
Carbohydrates and weight loss:
carbohydrates have fewer calories per
gram than fat. Trick: eat in moderation
and use complex carbohydrates, not
refined sugars.
 Refined sugar recommendations: no
more than 12 tsp/day, less than 10% of
calorie intake, Table 4.1. The average
current intake in American is 31 tsp/day.

Why fiber?
Decreases the risk of cardiovascular
diseases: binds cholesterol and bile,
and decreases our intake of fatty foods
by making us feel full
 Helps control blood glucose

Why fiber?

Improves health of digestive tract: stimulates
muscles (digestive tract muscles need
exercise too!, prevents constipation,
appendititis and formation of diverticuli
 Colon cancer and fiber:


Older studies have shown that diets that provide
adequate fiber prevent colon cancer.
New studies shows that fiber supplements do NOT
prevent colon cancer. i.e. Eat your fruits and
veggies because they seem to have
phytochemicals that prevent cancer.
Digestion and Absorption of
Carbohydrates

Blood carries monosaccharides to the
liver.
Glucose is absorbed directly into the blood
stream – no digestion required.
 All carbs are converted to glucose.
 Glucose travels to other cells via the blood.
 Extra glucose is stored as glycogen in the
liver and skeletal muscles.

How do our bodies use glucose?

In the absence of glucose our bodies use
protein (muscle tissue) as fuel.
 Fat is also potential fuel but requires
carbohydrates to be used properly. Without
carbs, fat breakdown is incomplete and
produces ketosis.
 Ketosis – causes the body fluids to become
more acidic and this dissolves bone, promotes
kidney stones, bad breath, high cholesterol,
high blood pressure, even death.
How to Read the Carb Label
o
See the total Carbohydrates
for this label?
31 grams
Dietary fiber is 0 grams
Sugars account for 5 grams
If the dietary fiber was 5
o
grams – we could deduct 5
grams from the 31 for a total
of 26 carb grams.
Why can we deduct fiber?
o
o
o
o