INSULIN: THE TWO-FACED HORMONE

The hormone insulin is like your pack-rat grandmother: It likes to store stuff.
The only problem is that it’s also as schizophrenic as old Uncle Judd. Sometimes
it makes your muscles grow; sometimes it makes your fat cells grow.
Different foods create different insulin responses. Foods that have
high–glycemic index rankings (including white bread, most cereals, grapes,
and bananas) dump a lot of sugar into your bloodstream soon after eating,
causing insulin levels to spike. In this case, insulin works quickly to turn that
blood sugar into fat.
Some foods, though, cause a different reaction. Dairy products—milk, yogurt,
ice cream—create dramatic insulin surges without the corresponding
effect on blood sugar. You also get this insulin response from some foods
that are virtually carbohydrate-free, such as beef and fish, which have hardly
any effect on blood sugar. When blood sugar remains relatively constant, it
allows insulin to use the nutrients in your blood to build and repair cells, including
muscle tissue.
That’s why the Abs Diet centers around high-fiber, nutrient-dense foods that
are also the ones thought to be most useful for weight control. Most are moderate
to high protein, some are high in dairy calcium, and those that are carbbased
emphasize fiber and other important nutrients.
(By the way, if all this talk about blood sugar and insulin reminds
you of a certain health problem—diabetes—then you were
obviously paying attention in health class. Continuing to flood
your bloodstream with high levels of sugar, followed by high levels
of insulin, eventually trains your body to become less efficient at
processing these blood sugars. That’s called insulin resistance,
which is another term for diabetes. It is a terrible, terrible disease—
and it is also highly preventable. In a Harvard study, men
who ate foods with the lowest GIs, like whole-wheat bread, were
37 percent less likely to develop diabetes than those who ate high-
GI foods, such as white rice. For more information on battling diabetes,
see our Health Bulletin on page 50.)
It’s hard to generalize about which carbs are high on the GI
list and which are low, because glycemic index is simply a measure
of time—that is, how long it takes 50 grams of the food’s carbohydrates
to turn into blood sugar, regardless of serving size. It’s
a measure, for instance, of the carb-to-sugar conversion time for a
whole apple or watermelon, but it doesn’t tell you how much carb
is in one serving of the food. Nobody eats a whole watermelon,
anyway.
That’s why the latest advancement in food science is to look at
a meal’s glycemic load (GL). The GL considers both the GI of a
food and the amount of carbs in one serving of that food. It helps
you gauge the glycemic effect, or the projected elevation of blood
glucose, that food will cause.
The higher a food’s GL, the more it will cause your blood
sugar to spike, and the less control you’ll have over your energy
levels and your appetite. But considering the GL is only one aspect
of creating a balanced diet. “It’s better to have a high-GL
diet than one full of saturated fat,” says Jennie Brand-Miller,
Ph.D., professor of human nutrition at the University of Sydney
and author of the International Table of Glycemic Index and
Glycemic Load. “Aiming for the lowest GL possible is not a good
H O W T H E A B S D I E T W O R K S 69
move because that means you’ll be eating too little carbohydrate
and too much fat—probably saturated fat.” Instead, to maintain
you’re body’s best glycemic response, center your meals around
foods with GLs of 19 or less and shoot for a GL of less than 120
for the whole day.
Sound confusing? It doesn’t need to be. The Abs Diet Powerfoods
and the Abs Diet recipes all have low to moderate glycemic
loads. All you have to do is follow the plan. And on those occasions
when you are stuck and need to choose between two or more foods,
refer to the chart on page 276.