If you're one of those people who can't stand all the counting
and tracking and adding and charting that some diets require,
you could find a refuge in one simple numerical scale: the
glycemic index. On the other hand, you might find it another
maddening way to complicate the simple act of eating.
The glycemic index is a measure of the quality of carbohydrate
foods. It's kind of a good carbs/bad carbs thing, based on how
they affect your blood sugar. Though it's not new, it did start
getting a lot of press when the anti-carb movement took hold.
It works like this: in the glycemic index , pure glucose is
arbitrarily assigned the score of 100; it doesn't mean anything
in particular; it's just a set reference point for how it has
affected the blood sugar by about two hours after eating. Then
all other foods in the index are given a number relative to
glucose and its affect on the blood sugar.
Foods with a low index typically break down slowly and don't
cause drastic fluctuations in blood sugar. Foods with a high
index typically do. For instance, green peas have an index of
39, while corn flakes have an index of 92.
Originally developed to help folks—particularly
diabetics—control their blood sugar, the index includes mainly
carbohydrate foods, because protein and fat don't have much
immediate effect on blood sugar.
But assigning numbers to different foods based on their
glycemic effect just happens to create a scaled list of foods
that ends up being a very useful tool for people dealing with
obesity and other health issues, as well. That's because simply
maintaining a low-glycemic index diet tends to guide people
toward healthier eating and weight loss, even when that is not
their specific goal.
Consider: Type II diabetes, as well as various cancers and
cardiovascular disease, are all highly correlated with high
index diets. There's abundant research that shows that reducing
the overall glycemic index also reduces the risks of those
problems.
That's because almost by default, a low-index diet will include
more fresh fruits and vegetables, more fiber, more dairy, all
foods that offer essential nutrients, that are more likely to
be lower in calories and which tend to keep the body sated
longer, holding off the next hunger spell. All that usually
adds up to weight loss, no matter what the program.
Proponents of the index say it's more helpful than counting
calories or grams of fats or carbs, and actually offers a
simplified approach to learning to eat better, but some experts
caution that people shouldn't get too wrapped up in worrying
about the precise numbers. Instead, they urge that people pay
attention to whether the foods they're eating have a low,
medium or high index.
That's because, as with any rule, there are exceptions to the
fairly consistent physiological rules that underlie the index.
For instance, watermelon has a pretty high glycemic index,
about 75, which is even higher than table sugar. Does that make
it bad for you? No. Because in spite of its high index,
watermelon actually has a pretty low glycemic load. That's a
measure based on the amount of food you'd actually consume, not
just an arbitrary quantity used in testing, as with the index.
The glycemic load of a food can be determined using the
glycemic index number for a food, divided by 100 and multiplied
times the available carbohydrate you'd eat. With most foods, low
index is consistent with low load, but there are the quirky
exceptions. Of course, to find them, you'd be back to doing a
bunch of math again, and that's just not the way people
normally eat.
That's why doctors and nutritional experts encourage people who
are trying to develop a healthy diet to avoid getting caught up
in the numbers game and look more generally at the foods in the
index, leaning toward those at the low end. Anything over 70 is
considered high index, 55 through 69 is medium and below 55 are
foods with a low glycemic index.
And look what's in those groups: high index foods include most
breakfast cereals, white breads and other processed baked
goods, most potatoes, ice cream, candies and table sugar, your
veritable Atkins nightmare.
Lower index foods include cherries, grapefruit, broccoli,
legumes like lentils and beans, most whole grain baked goods
and most dairy foods. So even without counting calories or
keeping track of specific index numbers, you can see that
steering your diet toward the low end of the index is bound to
do you good.
We like to encourage patients to think of glycemic index and
glycemic load as just two more tools that can be helpful in
developing healthier thinking and planning about dietary
habits.
A final thing to remember: there's not one standardized
glycemic index list and most indexes include brand-name items
that people buy on a typical shopping trip, as well as the more
generic items like vegetables and fruits. This is one of the
more helpful aspects of the lists, but only if you get one that
relates to where you live.
If your average Southwest Florida resident looked at an index
created in Australia, it wouldn't be much help, because really,
when's the last time you had a couple Golden Pikelets with a
nice glass of Milo?
THROUGH THICK & THIN
Fruits tend to have a high glycemic index, so I recommend that
people take their fruits with a meal, or with some protein like
cottage cheese or regular cheese. These protein sources help
mitigate the fruits glycemic effect. Don't let a high index
number keep you away from your apple a day.
About The Author: Caroline J. Cederquist, M.D. is a board
certified Family Physician and a board certified Bariatric
Physicians (the medical specialty of weight management). Dr.
Cederquist is the founder of http://www.bistromd.com formerly
Diet To Your Door, a home diet delivery program.
