Is There a Magic Weight Loss Carb?
Brown ... white ... high index -- all terms used to describe carbohydrates. But is there one that can really help you drop a few extra pounds? Oprah thinks so. See what the experts think.
Just as we've been hearing more and more about good and bad
fats, diet gurus are starting to talk more about good and bad carbohydrates.
And word is getting around.
On her television show, Oprah Winfrey claimed to have lost
weight by switching from bad carbs to good. Likewise, many diet programs, such
as Body-for-Life, tout the health benefits of good carbs. But are there really
such things as good and bad carbohydrates?
"Some carbs are better than others, but it's not really a
question of one carb being 'good' and one being 'bad,'" says Jack Alhadeff,
PhD, professor of biochemistry at Lehigh University in Bethlehem, Pa.
"If you're eating to get energy for physical activity right
away, simple carbs -- pasta, white bread, processed cereals, and the like --
work well. If someone is heavy or wants to manage weight, it is smart to chose
Why? Because all carbohydrates are broken down into sugar, or
glucose, which is the body's fuel. Carbohydrates with little fiber break down
quickly. Those foods with carbohydrates trapped in fiber take longer to break
down. The rate at which this happens can be represented on what nutritionists
call the glycemic index.
Is Glycemic Index Useful?
Foods high on the index turn to glucose fast. But that speed
can cause a spike in levels of the hormone insulin, which the body needs to
process glucose into physical energy. Foods low on the index -- sweet potatoes,
brown rice, leafy greens, fat-free milk -- break down slowly and result in
lower insulin levels.
"Unless you're a diabetic, glycemic index may not be all
that important," says Alhadeff, who adds that since most of us eat a
variety of foods in a meal, the accuracy of the index can be questionable.
But what about the notion that glucose from high-index foods is
more likely to be stored as fat?
"The scientific literature is very clear that eating
carbohydrates that are embedded in plant cellulose -- complex carbohydrates --
is always better," says Nagi Kumar, PhD, director of clinical nutrition at
the Moffitt Cancer Center and professor of human nutrition at the University of
South Florida in Tampa. "But the reasons it is better are not because it
somehow lessens or alters fat storage."
She says that fiber-rich carbohydrates increase the bulk of the
meal, making you feel fuller. This in turn, helps moderate the amount of food
So, what is fiber, exactly?
There are two types of fiber: soluble and insoluble.
Nutritionists describe soluble fiber as a sticky substance that is found in
fruit, vegetables, dried beans and peas, and oat products. Insoluble fiber,
which is gritty in texture, accounts for 70% of the fiber in our diets, mostly
from wheat bran.