Carbohydrates and Glycemic Index
Carbohydrates are absorbed by the body at varying rates.
The glycemic index (GI) measures how much a fixed amount of carbohydrates
from a food raise glucose level. Thus high GI carbohydrates
are digested quickly and so tend to lead to hunger, whereas low
GI carbohydrates tend to suppress hunger. GI does not
take into account the caloric density and other factors
influencing a food's glycemic effect. A better measure is
glycemic load, which refers to how much a standard serving
raises glucose levels. When I find values of the glycemic
load, I'll post them instead.
Current recommendations are that at least 1/3 of your carbohydrates
should have a GI that is 55 or below (Dr. Wolever, coauthor of
The Glucose Revolution: The Authoritative Guide to the Glycemic
Index in a Bottom Line, Jan. 15, 2001).
It was once thought that high sugar meant high
GI (bad) and complex carbohydrates meant low GI (good), but it
is not that simple. Here
is some information for specific foods.
- FRUITS There
is a wide range.
Two rough rules are: more tropical
is higher and sweeter is higher.
From low to high:
25 grapefruit, plum
40 apple, pear, plum
45 grape, orange
55 apricot, banana, mango
65 cantaloupe, pineapple, raisin
- GRAINS Generally,
less processed means lower GI. Also, whole grains appear
better than refined ones with similar GIs (SN 5/18/02 p.308).
Barley ranges from 25 (pearled)
to 65 (rolled).
Breads range from 40 (punpernickel)
to 95 (French) and are mostly in the 60s.
Cereals have a wide range.
Most of those not thought of as sweet are from the 60s to the
the low end, All-Bran is 40. At the high end, Rice
Chex is 90.
Pastas (including whole grain)
range from around 35 for al dentes to 50 for well cooked.
Rice (white, brown, wild) is about 55, depending on variety
and cooking. Stickiness indicates high GI.
Rye (whole) is 35.
Wheat (whole) is 40.
- VEGETABLES There
is a wide range.
Carrot is 70.
Corn is 55.
Legumes are in 30s and 40s,
but Soy is only 20. Canning often adds 5-10 to values.
Parsnip is an amazing 95!
Potatoes are 85/60 for boiled red/white and 95/85 for
Pumpkin is 75.
Rutabaga is 70.
Sweet potato is 55.
Chocolates are around
Ice creams are around 60.
Milks are around 30, depending
on fat percentage (skim is highest; whole is lowest).
Peanut is 15. (The
only "nut" I found.)
Yogurt (plain) is about 15.