Transcript Going for the 3 Increases: Increase in Health, Increase in

Glycemic Index & Glycemic Load
Going for the 3 Increases: Increase in Health, Increase in
Happiness & Increase in Energy
Strategies for
Success in Weight
Management
By: James J. Messina, Ph.D.
Gylcemic Index – GI
A GI value tells you only how rapidly a
particular carbohydrate turns into sugar
 Not all carbohydrates act the same
 Some are quickly broken down in the
intestine, causing the blood sugar level to
rise rapidly
 Such carbohydrates have a high
glycemic index (GI).

Gylcemic Load - GL
Tells you how much of that carbohydrate
is in a serving of a particular food
 You need to know both the GI Gylcemic
Index and the GL Gylcemic Load
understand a food’s effect on blood sugar
 Calculating GL allows researchers to
better relate carbohydrate intake to its
health effects

How to Calculate GL
GL is amount of carbohydrate in serving
of food multiplied by that food’s GI
 Glycemic load of a food is calculated by
multiplying glycemic index times the
carbohydrate content of food divided by
50g. (GI x CHO content of food / 50 g)
 A 12 cup serving of carrots (which has 8
grams of carbohydrate) has a glycemic
load of about 10 (8 * 131%, or 1.31 =
10.48).

Comparison of GL and GI
GI of a baked potato is 121% (assuming
white bread is the standard reference
food)
 This has earned the potato, which is
largely carbohydrate, a place on the
“avoid” list in publications and on Web
sites promoting the GI approach to food
choices

Comparison of GL and GI
GI of carrots is high: 131%. But this
unfavorable GI rating is based on the
blood-sugar effect of eating 50 grams of
carbohydrate from carrots — the amount
contained in 1 ½ pounds — which few
people would consume in one sitting
 A serving of carrots doesn’t have much
carbohydrate, so its impact on blood
sugar is much less than that of a serving
of potato

Comparison of GL and GI
Avoiding carrots because of their GI
ranking would be a big mistake,
particularly given all the vitamins and
minerals they contain and the low GL of
each serving
 The GI of potatoes, on the other hand, is
not a misleading measure because
potatoes are carbohydrate-dense. Their
GL is also fairly high

Research tells us to lower GL in
diet
In American Journal of Clinical Nutrition
(March 2001), Nurses’ Health Study
researchers used blood samples & foodfrequency questionnaire
 Used GL measures to assess the impact
of carbohydrate consumption on 280
postmenopausal women

Research tells us to lower GL in
diet
High-GL diets (and, by extension, high GI
foods and greater total carbohydrate
intake), correlated with lower HDL
concentrations and higher triglyceride
levels, a marker for heart disease
 Strongest association was in overweight
women, i.e., those whose body mass
index (BMI) was over 25. Increased risk
started, on average, at a daily GL of 161

How to use the GL in your food
plans
Knowing a food’s GL can help you make
comparisons that can improve the quality
of your carbohydrate choices
 Good idea to replace processed and
refined-grain carbohydrates, such as
those found in many snacks and
desserts, with fruits & non-starchy
vegetables

How to use the GL in your food
plans
Substitute:
 whole grain bread for white bread
 wild rice for white rice
 beans or lentils for potatoes
 Recognize that fruits & non-starchy
vegetables as well as whole grains &
beans, are rich in nutrients & contain
fiber, which slows digestion & moderates
blood sugar levels
Online References on GI & GL
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http://www.ajcn.org/cgi/content/abstract/71/6/1
455
http://archinte.amaassn.org/issues/v161n4/abs/ioi00112.html
http://www.glycemicindex.com/
http://www.mendosa.com/gi.htm