AACVPR News & Views - April/May 2015 - 10

INSIDE >> THE INDUSTRY

The GI value of a food is
determined by giving people a
serving of the food that contains 50
grams of carbohydrate minus the
fiber, then measuring the effect on
their blood glucose levels over the
next two hours.

and beverages for 5 weeks. The
participants were randomized into
one of four diets.

A serving of 50 grams of
carbohydrate in one sitting is
reasonable for a food like rice, which
has 53 grams of carbs per cup. But
for beets, a GI ranking of 64 is a little
misleading. Since beets have just 13
grams of carbs per cup, we would
need to consume nearly 4 cups of
beets in order to cause that spike in
blood sugar levels.

2.

The results of a recently published
randomized crossover-controlled
feeding trial, conducted in research
units in academic medical centers
with 163 overweight adults were
given all their meals, snacks,

1.

3.

4.

high-glycemic index
(65% on the glucose scale),
high carbohydrate diet
(58% energy);
low glycemic index (40%),
high carbohydrate diet;
high glycemic index,
low carbohydrate diet
(40% energy); and
low glycemic index,
low carbohydrate diet.

Each diet was based on a DASH
type diet. Diets with low glycemic
index of dietary carbohydrate,
compared with high glycemic index
of dietary carbohydrate, did not
result in improvement in insulin
sensitivity, lipid levels, or systolic
blood pressure.
An alternative to Glycemic Index
is Glycemic load (GL). The GL is a

formula that corrects for potentially
misleading GI by combining portion
size and GI into one number. The
carbohydrate content of the actual
serving is multiplied by the food's GI,
then that number is divided by 100.
So for a cup of beets, the GL would
be: 13 times 64 = 832 divided by
100 = a GL of 8.3.
As a frame of reference, a GL higher
than 20 is considered high, between
11 and 19 is considered moderate,
and 10 or less is considered low.
The bottom line: the glycemic index
isn't a perfect system. It can be a
useful tool to identify lower-glycemic
foods that are often more nutrientdense, as well as what foods are
higher in refined carbohydrates.
Additional resources may be
found here. 

The Glycemic Load is a formula that corrects
for potentially misleading GI by combining
portion size and GI into one number.

10

News&Views APRIL/MAY 2015
http://www.eatright.org/resources/food/nutrition
AACVPR News & Views - April/May 2015

Table of Contents for the Digital Edition of AACVPR News & Views - April/May 2015
