How is a gi value determined
What Is The Glycemic Index - What Is Glycemic Load - Glycemic Index Explained - Glycemic Index Diet
what's up dudes and what's up ladies
Brian here and in this video we're gonna
look at the glycemic index and glycemic
load I'm going to show you how each of
these is derived benefits and drawbacks
of each of them and some other factors
that affect them so what is the glycemic
index it is a way to analyze
carbohydrate foods based on their impact
on blood sugar levels the GI ranks
carbohydrates on a scale of 0 to 100
based on how much they raise blood sugar
levels after eating foods with a high GI
are rapidly digested and absorbed and
therefore caused large fluctuations in
blood sugar levels lower GI foods are
more slowly digested and produced
gradual rises in blood sugar levels how
is a foods glycemic index value
determined well after an overnight fast
a group of 10 people are given a serving
of a food item this serving contains 50
grams of available carbohydrates
available carbohydrates does not include
the fiber content after the food has
been consumed blood sugar levels are
measured every fifteen to thirty minutes
over a two hour period these results are
plotted on a graph
next the people are given 50 grams of
carbohydrates of a reference food either
white bread or pure glucose the same
process is followed and these results
are plotted the area under the curve for
the reference food is given a value of
100 the area under the curve of the test
food is then calculated as a percentage
of the reference food area whatever that
percentage is is its glycemic index
value this is how the glycemic index
rates foods most organizations use a
high medium and low rating scale
carbohydrates with a glycemic index
value of 55 or less are rated as low a
medium value lies between 56 and 69 and
a high value is 70 or more now let's
look at glycemic load glycemic load is
another way to analyze carbohydrate
foods it takes into account portion
sizes while the glycemic index looks
only at 50 gram carbohydrate amounts
glycemic load looks at the available
carbohydrates in a portion size the
glycemic load equal
is as follows available carbohydrates in
a portion size times the glycemic index
of the food divided by 100 the scale
Fergus emic load is as follows high
equals 20 or more medium is 11 to 19 and
low is 10 and under let's look at a
couple of examples here we have a
serving size of 1 cup of diced pineapple
which contains 19 point five grams of
carbohydrate and two grams of fiber
giving it 17.5 grams of available
carbohydrates and here we have a serving
size of one cup of watermelon which
contains about 11.5 grams of
carbohydrate and 0.6 grams of fiber so
hey it has roughly 11 total grams of
available carbohydrates next we have a
serving size of two slices of white
bread which contains about 24 total
grams of available carbohydrates the GI
value of the pineapple is 66 watermelon
is 72 which puts it in the high GI
category and white bread has a GI of 70
I'm going to put the glycemic load
calculations on the screen for you we
see that the glycemic load for the
serving of pineapple is eleven point
five five watermelon is seven point nine
two and white bread is sixteen point
eight this would put the watermelon in
the low glycemic load category and the
pineapple and white bread into the
medium glycemic load category so as you
can see the glycemic load takes into
account the portion size however over
eating any food will dramatically
increase its glycemic load I'll put a
couple of links in the description box
below where you can see the glycemic
index and glycemic load of many
different foods the glycemic index and
glycemic load are not foolproof let's
take a look at icecream
it has a glycemic index of 36 really
good a serving size of one cup yields a
glycemic load of about eleven point five
two so a low glycemic index and a medium
glycemic load not too bad but why are
these numbers so low well when we look
at the total profile of ice-cream
we see it as 14 grams of fat eight grams
of saturated fat in one serving
so as the body digests it the glucose
release will be slower because the body
has to break down the fat in addition to
the carbohydrates this gives it a lower
glycemic index other things that affect
the food's glycemic index value is how
it's cooked any cooking will raise the
food's value however slow cooking will
not raise a glycemic index value nearly
as much as fast cooking such as
microwaving the more of food has been
processed the higher the glycemic index
value will be and what other types of
foods it is being consumed with will
affect its value as well the glycemic
index and glycemic load can be useful in
relation to blood sugar level spikes
however because the food has a low
glycemic index or glycemic load value
this does not mean the food is healthy
or unhealthy the glycemic index and
glycemic load can be a helpful tool in
evaluating food however it's only one
tool look at the fat content the fiber
content look at how much processing the
food has gone through and how the food
was cooked one last thing many studies
have shown that consumption of lower
glycemic foods has delayed the return of
hunger and decreased subsequent food
intake research continues on that
subject as we always say here try and
increase your whole food consumption try
and minimize the processed foods but
don't be afraid to eat the food you love
just do it in moderation
