Post by JJ Judkins on Jul 30, 2012 22:50:44 GMT -6
The hidden EFFECTS of food (diabetes)
The glycemic load is a more powerful factor in keeping you healthy than the
amount of carbohydrate¬ or fat-you eat.
and other serious illnesses over the long haul, meals loaded with these Now
you're in on the secret: Most of us are damaging our health by eating too
many foods that send our blood sugar soaring. Besides contributing to
diabetes foods also leave you tired, grumpy, and hungry again in no time
after you eat them. Other foods barely move the blood sugar needle or move
it gradually, keeping you feeling full and energized.
Unfortunately, foods don't come with labels explaining which is which. After
reading this chapter, though, you'll know how to tell the difference.
In the end, it's as simple as choosing pasta over rice, baked beans instead
of mashed potatoes, oil-and-vinegar dressing instead of Thousand Island, and
other easy fixes. Read on to discover what makes these foods Magic.
First, we'll talk about the three so-called macronutrients in
food-carbohydrate, fat, and protein-from which we get almost all of our
calories, and we'll tell you how they affect your blood sugar. Then we'll
talk about two "magic" food components you can use for amazingly effective
blood sugar control: soluble fiber and acetic acid, found in sour foods.
Carbohydrate
We'll reveal the main plot twist right now:
Carbohydrates are the foods that raise blood sugar. Plain and simple, right?
The trouble is, not all carb foods are created equal.
Carbohydrates are actually found in most foods except fats and oils, meats,
poultry, and fish. But of course, some foods contain more carbs than others.
Beans are about one-fourth protein and three-fourths carbohydrate. Rice, on
the other hand, is more than 90 percent carbohydrate. Whole milk contains
all three macro nutrients: fat, protein, and carbohydrate.
It's the quantity of carbohydrate in foods (and of course, how much of the
food you eat) that primarily affects blood sugar, but the type of
carbohydrate also has an effect.
Introducing the Glycemic Index and Glycemic Load
To figure out which carbs are best and worst for blood sugar, scientists had
to do some serious detective work. First, they needed to come up with a way
to measure a food's effect on blood sugar.
Nutrition scientist David Jenkins, M.D., Ph.D., developed a system called
the glycemic index (GI) back in 1981 (the prefixglyc- means "sugar"). He had
volunteers eat different foods, all containing 50 grams of carbohydrate.
Then he measured the volunteers' blood sugar over the following 2 hours to
see how high it went.
As a control he used pure glucose, the form of sugar that's identical to
blood sugar-your body converts glucose very quickly to blood sugar¬ and
assigned it the number 100 on his new index.
The glycemic index opened a lot of eyes. Almost everyone had assumed that
table sugar would be the worst offender, much worse than the "complex
carbohydrates" found
in starchy staples such as rice and bread. But this didn't always prove
true. Some starchy foods, like potatoes and cornflakes, ranked very high on
the index, raising blood sugar nearly as much as pure glucose. That's why
you won't see these foods in our list of Magic foods.
The higher the glycemic load in the diet, the greater the incidence of
obesity, diabetes, heart disease, and cancer.
WHERE THE GLYCEMIC INDEX FELL SHORT
Something was wrong, however. Some of the results pointed fingers at healthy
foods, such as carrots and strawberries.
Watermelon was just about off the top of the GI chart. But no one ever
gained weight from eating carrots, nor do carrots, in the real world, raise
blood sugar. What was the GI missing?
The GI measured the effects of a standard amount of carbohydrate: 50 grams,
or about 11/2 ounces. But you'd be awfully hard-pressed to eat enough
carrots-seven or eight large ones-to get 50 grams of carbohydrate. The same
holds true for most other vegetables and fruits. They're full of water, so
there's not much room in them for carbohydrate. Bread, on the other hand, is
crammed with carbohydrate. You get 50 grams by eating just one slice.
To solve the problem, scientists came up with a different measurement: the
glycemic load (GL). It takes into account not only the type of carbohydrate
in the food but also the amount of carbohydrate you would eat in a standard
serving. (To get a bit technical, a food's GL is the GI multiplied by the
amount of carbohydrate in one serving.)
This made more sense. By this criterion, carrots, strawberries, and other
low-calorie foods are clearly good to eat-they all have low GL values, since
the amount of carbohydrate they contain is low.
The GL has turned out to be a powerful way to think about not just
individual foods but also whole meals and even entire diets. When scien¬
tists looked at the GL of typical diets in different populations, they found
that the higher the GL, the greater the incidence of obesity, diabetes,
heart disease, and cancer. You may remember a study we mentioned in Chapter
1 in which men who ate the most sugar-boosting foods were 40 percent more
likely to get diabetes. That's GL we were talking about. We also talked
about the Nurses' Health Study finding that women were twice as likely to
develop heart disease over 10 years if they ate more sugar-boosting foods.
Again, the GL. The converse is also true: The lower the GL of your diet, the
more likely you are to keep your weight under control and stay free of
chronic disease.
When it comes to eating right, controlling weight, and preventing disease,
the GL is a heavy hitter. It's a more powerful factor in keeping you healthy
than the amount of carbohydrate- or fat-you eat.
What Makes Some Carbs Better than Others
Why would one high-carb food have a different GL than another? Why does
white rice, for instance, have a higher GL than, say, honey? It has to do
with the way nature constructed them.
Carbohydrates consist of starches and sugars.
Starch-think of starchy foods like beans and potatoes-is made up of sugar
molecules bound together in long chains. When you eat a carbo¬ hydrate-rich
food, your body converts those starches and sugars into glucose, or blood
sugar. Some starches, like those in white rice, are extremely easy for the
body to convert, and therefore blood sugar levels rise like a hot temper
after you eat them. Others, like those in beans, take a lot more work to
break down, so blood sugar levels simmer rather than explode.
Four factors determine how fast the body breaks down carbohydrate.
CARB DENSITY COUNTS
The glycemic load takes into account how much carbohydrate a serving of food
contains.
The amount in one bagel equals the amount in five helpings of watermelon.
55 grams of carbohydrate 1 bagel = 5 cupd of water melon
THE TYPE OF STARCH-OR WHY TO AVOID STICKY RICE
Remember, starches are made of sugar molecules chained together. Some chains
have straight edges, while others are branched. The straight¬ edged type,
called amylose, is harder for your body to break down and turn into blood
sugar. The branched type, called amylopectin, is much easier to break down
because there are so many places for the enzymes that break down starch to
get at it. Think of a tree with lots of branches¬ there are a lot more spots
for birds to land on it compared to a simple post.
White potatoes are very high in amylopectin, the branched kind of sugar
chain, which is why they raise your blood sugar in a jiffy. Peas and lentils
are high in amylose, the straight kind, so they're converted to blood sugar
at a snail's pace.
The more amylose a food contains, the slower it will be digested and
converted into blood sugar. Take rice, for instance. Some types con¬ tain
more amylose than others. In general, the softer and stickier the rice is
after cooking, the lower its amylose content; this is why "sticky rice" is
dastardly to your blood sugar. The firmer the rice, the higher the amylose
and the harder
it is for your body to turn into blood sugar quickly-making brown rice a
better choice. Some genetic variants of rice-such as some
sold in Australia, for example-are particularly high in amylose (as much as
25 percent), but unfortunately, most of the rice we eat is low in amylose
and thus has a high GL.
THE TYPE OF SUGAR-OR WHY FRUIT IS A-OKAY
Sugar is the molecule that makes up carbohy¬ drates, but there is more than
one kind. There's table sugar (sucrose) as well as the kind found in fruits
and grains (fructose), the kind in milk (lac¬ tose), and the kind in malted
barley (maltose). The sugar in milk and fruit tends to be absorbed more
slowly than other sugars since it needs to be converted into glucose by the
liver first, which is why these foods are gentle to your blood sugar.
Ironically, table sugar, which is half fructose and half glucose, is turned
into blood sugar more slowly than some starches, like bread or pota¬ toes.
That doesn't make sugar good for you, of course. One reason is that
fructose, especially in the amounts contained in packaged foods loaded with
high-fructose corn syrup, raise triglyc¬ erides, blood fats that increase
the risk of heart attack. (Fruit, by contrast, contains a little fructose
plus plenty of water, fiber, and nutri¬ ents.) The other reason is that
sugar packs a lot of carbohydrate calories in a small package.
NOT ALL STARCHES ARE EQUAL Potatoes raise blood sugar fast because the type
of starch they contain is easily broken down. Peas contain a type of starch
that's broken down much more slowly.
potato (amylopectin)
peas {amylose}
That's why one 32-ounce (l-liter) cola drink con tains a whopping 400
calories-and will send your blood sugar soaring.
HEAT-WHY NOT TO OVERCOOK RICE OR PASTA
All starch, whether it's made of straight or branched chains, is composed of
crystals, which don't dissolve in cold water. Think of a grain of rice or a
piece of raw potato-put it in water and it stays the same. But heat breaks
down those crystals so the starch can dissolve in water-a little like a
snowflake that comes in from the cold. When you cook a starchy food, it
absorbs water and becomes easier to digest.
The more overcooked rice or pasta is, the faster it makes your blood sugar
rise. When starch is heated and then cooled, it can return, in part, to its
crystal form; that's why hot potatoes have a high GL, while potato salad's
is slightly lower. Just make it with olive oil instead of mayo to keep it
healthier.
PROCESSING-OR WHY TO AVOID WHITE FLOUR
Have you ever noticed that some wheat breads are as smooth as white bread,
while others have crunchy kernels in them? Those kernels take a long time
for your body to break down. So do any whole, intact grains, such as
wheatberries (small kernels of wheat, delicious in salads).
Modern commercial flour, on the other hand¬ especially white flour-is
extremely easy for the body to turn into blood sugar, which is why we
suggest throughout this book that you choose whole grains that are still
intact and foods such as beans, lentils, and wheatberries instead of those
made from white flour. (Unfortunately, we're surrounded by white-flour
foods. You'll need to make a conscious effort to cut back.)
Until the 19th century, the main way to turn grain into flour was to grind
it between stones, sometimes powered by a water wheel. Making very fine
flour took a lot of work, and it was
available only in small amounts to the rich. Then high-speed, high-heat
steel rollers, which make very fine flour quickly and inexpensively, were
invented, almost instantly transforming our diets into blood sugar
nightmares.
Modern manu¬ facturing also allows grains to be turned into highly
processed forms such as cornflakes or puffed corn snacks,
which tend to have higher GLs than grains left intact, like popcorn, or
those milled in an old-fashioned manner, like coarse, stone-ground whole
wheat flour used in stone¬ ground wheat bread.
PASTA GETS A PASSING GRADE
Bread, even many whole wheat breads, can raise your blood sugar pretty
quickly. Yet pasta, even if it's made from white flour, has a much lower GL.
How can that be?
Imagine putting cooked pasta and a piece of bread in a bowl of water. The
bread will fall apart, but the pasta won't. That's because in pasta dough,
the starch granules get trapped in a network of protein molecules, so it
takes more work-and more time-to get at them. That's why pasta releases its
carbs much more slowly than potatoes or most breads do, especially if it's
served al dente (slightly undercooked) . Similarly, gnocchi, a pasta-like
product made from durum wheat and potato flour, has a lower GL than
potatoes. You'll find pastas, especially whole wheat pastas and
protein-enriched pastas, on our list of Magic foods in Part 2.
Pasta is particularly good for you if you eat it as the southern Italians
do: cooked al dente, prepared with olive oil and beans or vegetables, served
in modest portions, and followed by a piece of fish or lean meat and perhaps
a side of garlicky greens and fruit for dessert. A huge bowl of overcooked
pasta with a butter or cream sauce is not what the doctor ordered.
Protein
Unlike carbohydrate, protein doesn't raise blood sugar. Your body breaks it
down into amino acids, which it uses as building blocks for muscles as well
as many compounds such as neurotransmit¬ ters, the brain's chemical
messengers. Unless you're on a diet that has no carbs, your body won't even
try to convert protein into blood sugar.
That's why you'll find protein foods such as fish, chicken, beef, pork, soy,
milk, eggs, and cheese on our list of Magic foods. If you substi¬ tute
calories from one of these foods for some of your carbohydrate calories,
your blood sugar will thank you. For instance, if you add shrimp to a rice
dish, you'll eat less rice, and the meal will have less impact on your blood
sugar.
While we're fans of protein, we're not sug¬ gesting a diet of fatty bacon,
greasy burgers, and the like. These are packed with saturated fat, and as
you'll read a bit later, saturated fat increases insulin resistance, which
is bad for your blood sugar. Lean protein foods, like fat-free milk and
chicken breast without the skin, are far better choices because they contain
fewer calories and less saturated fat. Fish and shellfish are defi¬ nitely
on the menu because they're not only low in saturated fat but also high in
heart-healthy omega-3 fatty acids. Beans, peas, and lentils, all high in
protein, have the added plus of being rich in fiber.
We're also not suggesting an extremely high protein, low carb diet. You'll
find out why in the next chapter.
More Pluses for Protein
There are also other benefits to protein. Some of the compounds our bodies
make from pro¬ tein's amino acids help regulate blood sugar, so including
protein in a meal means your body will handle the carbohydrates in that meal
more efficiently. That's one reason we want you to include a source of
protein with every meal. Another reason: Your body takes a while to break
down the protein in the foods you eat, and this slows the digestion of the
whole meal, including the carbs it contains, making for a slower rise in
blood sugar.
In one recent study, healthy volunteers ate a starchy breakfast (white
bread) followed by a starchy lunch (mashed potatoes and meatballs). On some
days, however, they got extra protein in the form of whey (dairy protein).
On days when they ate more protein, their blood sugar levels were more than
50 percent lower in the fol¬ lowing 2 hours than on days when they ate
mostly carbs. Another study, of people with dia¬ betes, found that adding
whey reduced their blood sugar response by 21 percent over the fol¬ lowing 2
hours.
Protein, especially the kind found in milk, also stimulates the pancreas to
produce insulin. That may not sound like a good idea since having high
levels of insulin over long periods of time is unhealthy. But the earlier
your body makes insulin in response to a rise in blood sugar, the less
insulin it may need to make-and the less likely you are to become insulin
resistant.
PROTEIN AND WEIGHT LOSS
Eating more protein-rich foods should even help you lose weight. Protein
puts a damper on hunger, expanding the time between when you eat and when
your stomach starts rumbling again. Research proves it. In a six-day study,
one group of volunteers went on a low-Gl, high¬ protein diet. The other
group followed a low-protein, high-carb diet. Both groups were allowed to
eat as much as they wanted-and the folks who ate the high-protein diet
consumed 25 percent fewer calories than those in the high¬ carb group. In a
longer study, lasting six months, high-protein dieters lost more weight than
high¬ carb dieters. They ate less because they felt fuller.
Getting enough protein can also help keep your metabolism running at full
speed. Usually, when you really cut back on calories-especially if you go on
a very low carb diet-your body resorts to breaking down muscle tissue for
energy. But muscle tissue burns up a lot of calo¬ ries even when you're not
flexing a thing, so breaking it down slows your metabolism. Eating plenty of
protein helps your body keep its muscle tissue.
In diet studies, people on moderately high pro¬ tein diets lost more body
fat and less muscle. A moderately high protein diet might get as much as 30
percent of its calories from protein, rather than the 15 to 20 percent most
people get. Twenty to 30 percent is the protein intake we recommend.
Fat
Fat has gotten a bad rap, to the point where most people think the less fat
you eat, the better. Research is proving that this just isn't true.
During the height of the low-fat craze, people loaded up on carbohydrates
like fat-free chips and low-fat cookies-foods laden with fast¬ acting
carbohydrates- thinking they were doing themselves good. What a mistake! They
were actually wreaking havoc on their blood sugar and eating just as many
calories in the bargain.
The fact is, fat's no demon. Some fats are posi¬ tively good for you and
your blood sugar, and they absolutely belong in your diet.
Like protein, fat doesn't raise blood sugar, so swapping carb-rich foods
such as pretzels for fat¬ rich foods such as nuts can be an excellent trade.
Also like protein, fat takes a while to digest.
Because it slows the rate at which food leaves your stomach, it can blunt
the blood sugar effect of a whole meal, even if that meal includes carbs.
Tossing your salad with olive oil or drizzling some on your pasta, adding
some nuts to your rice, broiling fatty fish for dinner, or using slices of
ripe avocado in your sandwich won't magi¬ cally lower your blood sugar, but
it will help.
THE POWER OF PROTEIN
Adding protein to a carbohydrate dish lowers the glycemic load of the dish¬
assuming you eat the same amount-because you end up eating less
carbohydrate. Protein itself also helps steady blood sugar.
SHRIMP-FRIED RICE IS LOWER GL THEN FRIED RICE.
Good Fat, Bad Fat
Notice that we've talked about nuts, oils, and fish instead of other fat
sources such as burgers or butter. It's true that adding fat lowers the GL
of a starchy food, but adding butter or sour cream to a heap of mashed
potatoes doesn't make it healthy. Quite the contrary.
Butter, which comes from cow's milk, is an animal food, and as with many
animal foods, most of the fat it contains is saturated. That's the kind that
clogs arteries. It's also bad for blood sugar. In both animal and human
studies, a diet high in sat¬ urated fat has been shown to trigger insulin
resistance, which it does in many ways. Saturated fat increases
inflammation, which is toxic to cells, including those that handle glucose.
It also makes cell membranes less fluid, so the insulin receptors there are
less responsive to insulin; the hormone bounces off them like water off a
drum rather than sticking to them.
It's clear that people who eat the most saturated fat are at the highest
risk of developing insulin resistance and metabolic syndrome. And as you
read in Chapter 1, these conditions increase your risk of heart disease and
diabetes.
The trick, then, is to avoid the worst of the "bad" fat foods, like marbled
steak, high-fat lunchmeats, butter, whole milk, full-fat cheeses, and ice
cream, and choose instead lean cuts of meat and poultry, fat-free or 1%
milk, low-fat cheese, and lean lunchmeats such as turkey, chicken, and
extra-lean roast beef.
Even better, embrace unsaturated fats, which can actually improve insulin
sensitivity, thus ben¬ efiting your blood sugar. These fats come mainly from
plants-think avocados, nuts and seeds, olives, and olive and canol a oil-and
fish and seafood. The Mediterranean diet, one of the healthiest diets in the
world, gets a moderately high 30 to 35 percent of its calories from fat,
mostly the unsaturated kind. This is the fat ceiling we recommend.
Protecting Your Heart
"Good" fats are also good for your heart. Swapping that cheeseburger for
seafood or that butter for peanut butter (a good source of unsat¬ urated
fat) lowers your "bad" LDL cholesterol while leaving "good" HDL cholesterol
alone. In fact, eating just a handful of nuts a few times a week can slash
your risk of getting heart disease by 25 percent.
So can eating fish a few times a week. Seafood contains omega-3 fatty acids,
which do a world of good for your heart by lowering triglycerides, helping
prevent blood clots, reducing inflamma¬tion, and promoting normal heart
rhythm. Eating just two servings of fish-especially fatty fish such as
salmon or mackerel-a week can reduce your risk of heart disease by a third
or more.
Losing weight
You'd think that if you want to lose weight, you should cut way back on fat,
which is high in calories. Pretty obvious, right? Surprisingly, recent
research has shown it's not necessarily true. A moderate-fat diet can be
every bit as effective as a low-fat diet in helping you lose weight-if you
choose mostly beneficial fats.
A bit of fat also makes meals more satisfying, which can make it easier to
stick to a healthy eating plan over the long haul. Try to go too low fat,
and you'll most likely throw in the towel at some point, probably sooner
rather than later. In one study of overweight men and women, those on a
moderate-fat diet lost about 9 pounds (4 kg) over 18 months, while those on
a low-fat diet actually wound up gaining more than 6 pounds (3 kg). One key
reason was dieting fatigue: Only 20 percent of those on the low-fat diet
were still actively participating by the end of the study, while 54 percent
of those on the moderate-fat diet were still at it.
Lower Blood Sugar with Soluble Fiber
Carbs, protein, and fat are all macronutrients¬ nutrients that provide the
vast majority of our calories. Fiber doesn't count because it isn't digested
by the body, so it provides not a single calorie. Nevertheless, it's an
extremely impor¬ tant element in a Magic diet.
There are two types of fiber: soluble and insol¬uble. Soluble fiber is the
kind that dissolves in water. It's found in oats, barley, beans, and some
fruits and vegetables. Insoluble fiber is found mostly in whole wheat and
some fruits and veg¬ etables. Both types are very good for you, but only
soluble fiber will help lower your blood sugar-in a big way.
How big? Researchers at a USDA Diet and Human Performance Laboratory tested
oatmeal and barley (which is even richer in soluble fiber than oatmeal) on
overweight middle-aged women. On days when the women ate oatmeal for
breakfast, their blood sugar levels over the following 3 hours were about 30
percent lower than when they ate a sugar-laden pudding. On days when they
ate barley cereal, it was about 60 percent lower.
BEST FOODS FOR SOLUBLE
Here you'll find the amount of soluble fiber per serving of various foods.
Remember, you're aiming for about 10 grams a day.
grains (1/2 cup cooked)
Barley 1 g
Oats 1 g
beans and peas (1/2 cup cooked)
Black beans 2g
Great Northern beans 1.5 g
Kidney beans 3g
Lima beans 3.5 g
Navy beans 2g
Pinto beans 2g
Black-eyed peas 1 g
Chickpeas 1 g
vegetables (1/2 cup cooked)
Broccoli 1 g
Brussels sprouts 3 g
Carrots 1 g
fruit (1 medium fruit, except where noted)
Apple1 g
Blackberries (1/2 cup)1 g
Grapefruit 2g
Orange 2g
Pear 2g
Prunes (1/4 cup) 1.5 g
Reader's Digest Magic Foods for Better Blood Sugar
The glycemic load is a more powerful factor in keeping you healthy than the
amount of carbohydrate¬ or fat-you eat.
and other serious illnesses over the long haul, meals loaded with these Now
you're in on the secret: Most of us are damaging our health by eating too
many foods that send our blood sugar soaring. Besides contributing to
diabetes foods also leave you tired, grumpy, and hungry again in no time
after you eat them. Other foods barely move the blood sugar needle or move
it gradually, keeping you feeling full and energized.
Unfortunately, foods don't come with labels explaining which is which. After
reading this chapter, though, you'll know how to tell the difference.
In the end, it's as simple as choosing pasta over rice, baked beans instead
of mashed potatoes, oil-and-vinegar dressing instead of Thousand Island, and
other easy fixes. Read on to discover what makes these foods Magic.
First, we'll talk about the three so-called macronutrients in
food-carbohydrate, fat, and protein-from which we get almost all of our
calories, and we'll tell you how they affect your blood sugar. Then we'll
talk about two "magic" food components you can use for amazingly effective
blood sugar control: soluble fiber and acetic acid, found in sour foods.
Carbohydrate
We'll reveal the main plot twist right now:
Carbohydrates are the foods that raise blood sugar. Plain and simple, right?
The trouble is, not all carb foods are created equal.
Carbohydrates are actually found in most foods except fats and oils, meats,
poultry, and fish. But of course, some foods contain more carbs than others.
Beans are about one-fourth protein and three-fourths carbohydrate. Rice, on
the other hand, is more than 90 percent carbohydrate. Whole milk contains
all three macro nutrients: fat, protein, and carbohydrate.
It's the quantity of carbohydrate in foods (and of course, how much of the
food you eat) that primarily affects blood sugar, but the type of
carbohydrate also has an effect.
Introducing the Glycemic Index and Glycemic Load
To figure out which carbs are best and worst for blood sugar, scientists had
to do some serious detective work. First, they needed to come up with a way
to measure a food's effect on blood sugar.
Nutrition scientist David Jenkins, M.D., Ph.D., developed a system called
the glycemic index (GI) back in 1981 (the prefixglyc- means "sugar"). He had
volunteers eat different foods, all containing 50 grams of carbohydrate.
Then he measured the volunteers' blood sugar over the following 2 hours to
see how high it went.
As a control he used pure glucose, the form of sugar that's identical to
blood sugar-your body converts glucose very quickly to blood sugar¬ and
assigned it the number 100 on his new index.
The glycemic index opened a lot of eyes. Almost everyone had assumed that
table sugar would be the worst offender, much worse than the "complex
carbohydrates" found
in starchy staples such as rice and bread. But this didn't always prove
true. Some starchy foods, like potatoes and cornflakes, ranked very high on
the index, raising blood sugar nearly as much as pure glucose. That's why
you won't see these foods in our list of Magic foods.
The higher the glycemic load in the diet, the greater the incidence of
obesity, diabetes, heart disease, and cancer.
WHERE THE GLYCEMIC INDEX FELL SHORT
Something was wrong, however. Some of the results pointed fingers at healthy
foods, such as carrots and strawberries.
Watermelon was just about off the top of the GI chart. But no one ever
gained weight from eating carrots, nor do carrots, in the real world, raise
blood sugar. What was the GI missing?
The GI measured the effects of a standard amount of carbohydrate: 50 grams,
or about 11/2 ounces. But you'd be awfully hard-pressed to eat enough
carrots-seven or eight large ones-to get 50 grams of carbohydrate. The same
holds true for most other vegetables and fruits. They're full of water, so
there's not much room in them for carbohydrate. Bread, on the other hand, is
crammed with carbohydrate. You get 50 grams by eating just one slice.
To solve the problem, scientists came up with a different measurement: the
glycemic load (GL). It takes into account not only the type of carbohydrate
in the food but also the amount of carbohydrate you would eat in a standard
serving. (To get a bit technical, a food's GL is the GI multiplied by the
amount of carbohydrate in one serving.)
This made more sense. By this criterion, carrots, strawberries, and other
low-calorie foods are clearly good to eat-they all have low GL values, since
the amount of carbohydrate they contain is low.
The GL has turned out to be a powerful way to think about not just
individual foods but also whole meals and even entire diets. When scien¬
tists looked at the GL of typical diets in different populations, they found
that the higher the GL, the greater the incidence of obesity, diabetes,
heart disease, and cancer. You may remember a study we mentioned in Chapter
1 in which men who ate the most sugar-boosting foods were 40 percent more
likely to get diabetes. That's GL we were talking about. We also talked
about the Nurses' Health Study finding that women were twice as likely to
develop heart disease over 10 years if they ate more sugar-boosting foods.
Again, the GL. The converse is also true: The lower the GL of your diet, the
more likely you are to keep your weight under control and stay free of
chronic disease.
When it comes to eating right, controlling weight, and preventing disease,
the GL is a heavy hitter. It's a more powerful factor in keeping you healthy
than the amount of carbohydrate- or fat-you eat.
What Makes Some Carbs Better than Others
Why would one high-carb food have a different GL than another? Why does
white rice, for instance, have a higher GL than, say, honey? It has to do
with the way nature constructed them.
Carbohydrates consist of starches and sugars.
Starch-think of starchy foods like beans and potatoes-is made up of sugar
molecules bound together in long chains. When you eat a carbo¬ hydrate-rich
food, your body converts those starches and sugars into glucose, or blood
sugar. Some starches, like those in white rice, are extremely easy for the
body to convert, and therefore blood sugar levels rise like a hot temper
after you eat them. Others, like those in beans, take a lot more work to
break down, so blood sugar levels simmer rather than explode.
Four factors determine how fast the body breaks down carbohydrate.
CARB DENSITY COUNTS
The glycemic load takes into account how much carbohydrate a serving of food
contains.
The amount in one bagel equals the amount in five helpings of watermelon.
55 grams of carbohydrate 1 bagel = 5 cupd of water melon
THE TYPE OF STARCH-OR WHY TO AVOID STICKY RICE
Remember, starches are made of sugar molecules chained together. Some chains
have straight edges, while others are branched. The straight¬ edged type,
called amylose, is harder for your body to break down and turn into blood
sugar. The branched type, called amylopectin, is much easier to break down
because there are so many places for the enzymes that break down starch to
get at it. Think of a tree with lots of branches¬ there are a lot more spots
for birds to land on it compared to a simple post.
White potatoes are very high in amylopectin, the branched kind of sugar
chain, which is why they raise your blood sugar in a jiffy. Peas and lentils
are high in amylose, the straight kind, so they're converted to blood sugar
at a snail's pace.
The more amylose a food contains, the slower it will be digested and
converted into blood sugar. Take rice, for instance. Some types con¬ tain
more amylose than others. In general, the softer and stickier the rice is
after cooking, the lower its amylose content; this is why "sticky rice" is
dastardly to your blood sugar. The firmer the rice, the higher the amylose
and the harder
it is for your body to turn into blood sugar quickly-making brown rice a
better choice. Some genetic variants of rice-such as some
sold in Australia, for example-are particularly high in amylose (as much as
25 percent), but unfortunately, most of the rice we eat is low in amylose
and thus has a high GL.
THE TYPE OF SUGAR-OR WHY FRUIT IS A-OKAY
Sugar is the molecule that makes up carbohy¬ drates, but there is more than
one kind. There's table sugar (sucrose) as well as the kind found in fruits
and grains (fructose), the kind in milk (lac¬ tose), and the kind in malted
barley (maltose). The sugar in milk and fruit tends to be absorbed more
slowly than other sugars since it needs to be converted into glucose by the
liver first, which is why these foods are gentle to your blood sugar.
Ironically, table sugar, which is half fructose and half glucose, is turned
into blood sugar more slowly than some starches, like bread or pota¬ toes.
That doesn't make sugar good for you, of course. One reason is that
fructose, especially in the amounts contained in packaged foods loaded with
high-fructose corn syrup, raise triglyc¬ erides, blood fats that increase
the risk of heart attack. (Fruit, by contrast, contains a little fructose
plus plenty of water, fiber, and nutri¬ ents.) The other reason is that
sugar packs a lot of carbohydrate calories in a small package.
NOT ALL STARCHES ARE EQUAL Potatoes raise blood sugar fast because the type
of starch they contain is easily broken down. Peas contain a type of starch
that's broken down much more slowly.
potato (amylopectin)
peas {amylose}
That's why one 32-ounce (l-liter) cola drink con tains a whopping 400
calories-and will send your blood sugar soaring.
HEAT-WHY NOT TO OVERCOOK RICE OR PASTA
All starch, whether it's made of straight or branched chains, is composed of
crystals, which don't dissolve in cold water. Think of a grain of rice or a
piece of raw potato-put it in water and it stays the same. But heat breaks
down those crystals so the starch can dissolve in water-a little like a
snowflake that comes in from the cold. When you cook a starchy food, it
absorbs water and becomes easier to digest.
The more overcooked rice or pasta is, the faster it makes your blood sugar
rise. When starch is heated and then cooled, it can return, in part, to its
crystal form; that's why hot potatoes have a high GL, while potato salad's
is slightly lower. Just make it with olive oil instead of mayo to keep it
healthier.
PROCESSING-OR WHY TO AVOID WHITE FLOUR
Have you ever noticed that some wheat breads are as smooth as white bread,
while others have crunchy kernels in them? Those kernels take a long time
for your body to break down. So do any whole, intact grains, such as
wheatberries (small kernels of wheat, delicious in salads).
Modern commercial flour, on the other hand¬ especially white flour-is
extremely easy for the body to turn into blood sugar, which is why we
suggest throughout this book that you choose whole grains that are still
intact and foods such as beans, lentils, and wheatberries instead of those
made from white flour. (Unfortunately, we're surrounded by white-flour
foods. You'll need to make a conscious effort to cut back.)
Until the 19th century, the main way to turn grain into flour was to grind
it between stones, sometimes powered by a water wheel. Making very fine
flour took a lot of work, and it was
available only in small amounts to the rich. Then high-speed, high-heat
steel rollers, which make very fine flour quickly and inexpensively, were
invented, almost instantly transforming our diets into blood sugar
nightmares.
Modern manu¬ facturing also allows grains to be turned into highly
processed forms such as cornflakes or puffed corn snacks,
which tend to have higher GLs than grains left intact, like popcorn, or
those milled in an old-fashioned manner, like coarse, stone-ground whole
wheat flour used in stone¬ ground wheat bread.
PASTA GETS A PASSING GRADE
Bread, even many whole wheat breads, can raise your blood sugar pretty
quickly. Yet pasta, even if it's made from white flour, has a much lower GL.
How can that be?
Imagine putting cooked pasta and a piece of bread in a bowl of water. The
bread will fall apart, but the pasta won't. That's because in pasta dough,
the starch granules get trapped in a network of protein molecules, so it
takes more work-and more time-to get at them. That's why pasta releases its
carbs much more slowly than potatoes or most breads do, especially if it's
served al dente (slightly undercooked) . Similarly, gnocchi, a pasta-like
product made from durum wheat and potato flour, has a lower GL than
potatoes. You'll find pastas, especially whole wheat pastas and
protein-enriched pastas, on our list of Magic foods in Part 2.
Pasta is particularly good for you if you eat it as the southern Italians
do: cooked al dente, prepared with olive oil and beans or vegetables, served
in modest portions, and followed by a piece of fish or lean meat and perhaps
a side of garlicky greens and fruit for dessert. A huge bowl of overcooked
pasta with a butter or cream sauce is not what the doctor ordered.
Protein
Unlike carbohydrate, protein doesn't raise blood sugar. Your body breaks it
down into amino acids, which it uses as building blocks for muscles as well
as many compounds such as neurotransmit¬ ters, the brain's chemical
messengers. Unless you're on a diet that has no carbs, your body won't even
try to convert protein into blood sugar.
That's why you'll find protein foods such as fish, chicken, beef, pork, soy,
milk, eggs, and cheese on our list of Magic foods. If you substi¬ tute
calories from one of these foods for some of your carbohydrate calories,
your blood sugar will thank you. For instance, if you add shrimp to a rice
dish, you'll eat less rice, and the meal will have less impact on your blood
sugar.
While we're fans of protein, we're not sug¬ gesting a diet of fatty bacon,
greasy burgers, and the like. These are packed with saturated fat, and as
you'll read a bit later, saturated fat increases insulin resistance, which
is bad for your blood sugar. Lean protein foods, like fat-free milk and
chicken breast without the skin, are far better choices because they contain
fewer calories and less saturated fat. Fish and shellfish are defi¬ nitely
on the menu because they're not only low in saturated fat but also high in
heart-healthy omega-3 fatty acids. Beans, peas, and lentils, all high in
protein, have the added plus of being rich in fiber.
We're also not suggesting an extremely high protein, low carb diet. You'll
find out why in the next chapter.
More Pluses for Protein
There are also other benefits to protein. Some of the compounds our bodies
make from pro¬ tein's amino acids help regulate blood sugar, so including
protein in a meal means your body will handle the carbohydrates in that meal
more efficiently. That's one reason we want you to include a source of
protein with every meal. Another reason: Your body takes a while to break
down the protein in the foods you eat, and this slows the digestion of the
whole meal, including the carbs it contains, making for a slower rise in
blood sugar.
In one recent study, healthy volunteers ate a starchy breakfast (white
bread) followed by a starchy lunch (mashed potatoes and meatballs). On some
days, however, they got extra protein in the form of whey (dairy protein).
On days when they ate more protein, their blood sugar levels were more than
50 percent lower in the fol¬ lowing 2 hours than on days when they ate
mostly carbs. Another study, of people with dia¬ betes, found that adding
whey reduced their blood sugar response by 21 percent over the fol¬ lowing 2
hours.
Protein, especially the kind found in milk, also stimulates the pancreas to
produce insulin. That may not sound like a good idea since having high
levels of insulin over long periods of time is unhealthy. But the earlier
your body makes insulin in response to a rise in blood sugar, the less
insulin it may need to make-and the less likely you are to become insulin
resistant.
PROTEIN AND WEIGHT LOSS
Eating more protein-rich foods should even help you lose weight. Protein
puts a damper on hunger, expanding the time between when you eat and when
your stomach starts rumbling again. Research proves it. In a six-day study,
one group of volunteers went on a low-Gl, high¬ protein diet. The other
group followed a low-protein, high-carb diet. Both groups were allowed to
eat as much as they wanted-and the folks who ate the high-protein diet
consumed 25 percent fewer calories than those in the high¬ carb group. In a
longer study, lasting six months, high-protein dieters lost more weight than
high¬ carb dieters. They ate less because they felt fuller.
Getting enough protein can also help keep your metabolism running at full
speed. Usually, when you really cut back on calories-especially if you go on
a very low carb diet-your body resorts to breaking down muscle tissue for
energy. But muscle tissue burns up a lot of calo¬ ries even when you're not
flexing a thing, so breaking it down slows your metabolism. Eating plenty of
protein helps your body keep its muscle tissue.
In diet studies, people on moderately high pro¬ tein diets lost more body
fat and less muscle. A moderately high protein diet might get as much as 30
percent of its calories from protein, rather than the 15 to 20 percent most
people get. Twenty to 30 percent is the protein intake we recommend.
Fat
Fat has gotten a bad rap, to the point where most people think the less fat
you eat, the better. Research is proving that this just isn't true.
During the height of the low-fat craze, people loaded up on carbohydrates
like fat-free chips and low-fat cookies-foods laden with fast¬ acting
carbohydrates- thinking they were doing themselves good. What a mistake! They
were actually wreaking havoc on their blood sugar and eating just as many
calories in the bargain.
The fact is, fat's no demon. Some fats are posi¬ tively good for you and
your blood sugar, and they absolutely belong in your diet.
Like protein, fat doesn't raise blood sugar, so swapping carb-rich foods
such as pretzels for fat¬ rich foods such as nuts can be an excellent trade.
Also like protein, fat takes a while to digest.
Because it slows the rate at which food leaves your stomach, it can blunt
the blood sugar effect of a whole meal, even if that meal includes carbs.
Tossing your salad with olive oil or drizzling some on your pasta, adding
some nuts to your rice, broiling fatty fish for dinner, or using slices of
ripe avocado in your sandwich won't magi¬ cally lower your blood sugar, but
it will help.
THE POWER OF PROTEIN
Adding protein to a carbohydrate dish lowers the glycemic load of the dish¬
assuming you eat the same amount-because you end up eating less
carbohydrate. Protein itself also helps steady blood sugar.
SHRIMP-FRIED RICE IS LOWER GL THEN FRIED RICE.
Good Fat, Bad Fat
Notice that we've talked about nuts, oils, and fish instead of other fat
sources such as burgers or butter. It's true that adding fat lowers the GL
of a starchy food, but adding butter or sour cream to a heap of mashed
potatoes doesn't make it healthy. Quite the contrary.
Butter, which comes from cow's milk, is an animal food, and as with many
animal foods, most of the fat it contains is saturated. That's the kind that
clogs arteries. It's also bad for blood sugar. In both animal and human
studies, a diet high in sat¬ urated fat has been shown to trigger insulin
resistance, which it does in many ways. Saturated fat increases
inflammation, which is toxic to cells, including those that handle glucose.
It also makes cell membranes less fluid, so the insulin receptors there are
less responsive to insulin; the hormone bounces off them like water off a
drum rather than sticking to them.
It's clear that people who eat the most saturated fat are at the highest
risk of developing insulin resistance and metabolic syndrome. And as you
read in Chapter 1, these conditions increase your risk of heart disease and
diabetes.
The trick, then, is to avoid the worst of the "bad" fat foods, like marbled
steak, high-fat lunchmeats, butter, whole milk, full-fat cheeses, and ice
cream, and choose instead lean cuts of meat and poultry, fat-free or 1%
milk, low-fat cheese, and lean lunchmeats such as turkey, chicken, and
extra-lean roast beef.
Even better, embrace unsaturated fats, which can actually improve insulin
sensitivity, thus ben¬ efiting your blood sugar. These fats come mainly from
plants-think avocados, nuts and seeds, olives, and olive and canol a oil-and
fish and seafood. The Mediterranean diet, one of the healthiest diets in the
world, gets a moderately high 30 to 35 percent of its calories from fat,
mostly the unsaturated kind. This is the fat ceiling we recommend.
Protecting Your Heart
"Good" fats are also good for your heart. Swapping that cheeseburger for
seafood or that butter for peanut butter (a good source of unsat¬ urated
fat) lowers your "bad" LDL cholesterol while leaving "good" HDL cholesterol
alone. In fact, eating just a handful of nuts a few times a week can slash
your risk of getting heart disease by 25 percent.
So can eating fish a few times a week. Seafood contains omega-3 fatty acids,
which do a world of good for your heart by lowering triglycerides, helping
prevent blood clots, reducing inflamma¬tion, and promoting normal heart
rhythm. Eating just two servings of fish-especially fatty fish such as
salmon or mackerel-a week can reduce your risk of heart disease by a third
or more.
Losing weight
You'd think that if you want to lose weight, you should cut way back on fat,
which is high in calories. Pretty obvious, right? Surprisingly, recent
research has shown it's not necessarily true. A moderate-fat diet can be
every bit as effective as a low-fat diet in helping you lose weight-if you
choose mostly beneficial fats.
A bit of fat also makes meals more satisfying, which can make it easier to
stick to a healthy eating plan over the long haul. Try to go too low fat,
and you'll most likely throw in the towel at some point, probably sooner
rather than later. In one study of overweight men and women, those on a
moderate-fat diet lost about 9 pounds (4 kg) over 18 months, while those on
a low-fat diet actually wound up gaining more than 6 pounds (3 kg). One key
reason was dieting fatigue: Only 20 percent of those on the low-fat diet
were still actively participating by the end of the study, while 54 percent
of those on the moderate-fat diet were still at it.
Lower Blood Sugar with Soluble Fiber
Carbs, protein, and fat are all macronutrients¬ nutrients that provide the
vast majority of our calories. Fiber doesn't count because it isn't digested
by the body, so it provides not a single calorie. Nevertheless, it's an
extremely impor¬ tant element in a Magic diet.
There are two types of fiber: soluble and insol¬uble. Soluble fiber is the
kind that dissolves in water. It's found in oats, barley, beans, and some
fruits and vegetables. Insoluble fiber is found mostly in whole wheat and
some fruits and veg¬ etables. Both types are very good for you, but only
soluble fiber will help lower your blood sugar-in a big way.
How big? Researchers at a USDA Diet and Human Performance Laboratory tested
oatmeal and barley (which is even richer in soluble fiber than oatmeal) on
overweight middle-aged women. On days when the women ate oatmeal for
breakfast, their blood sugar levels over the following 3 hours were about 30
percent lower than when they ate a sugar-laden pudding. On days when they
ate barley cereal, it was about 60 percent lower.
BEST FOODS FOR SOLUBLE
Here you'll find the amount of soluble fiber per serving of various foods.
Remember, you're aiming for about 10 grams a day.
grains (1/2 cup cooked)
Barley 1 g
Oats 1 g
beans and peas (1/2 cup cooked)
Black beans 2g
Great Northern beans 1.5 g
Kidney beans 3g
Lima beans 3.5 g
Navy beans 2g
Pinto beans 2g
Black-eyed peas 1 g
Chickpeas 1 g
vegetables (1/2 cup cooked)
Broccoli 1 g
Brussels sprouts 3 g
Carrots 1 g
fruit (1 medium fruit, except where noted)
Apple1 g
Blackberries (1/2 cup)1 g
Grapefruit 2g
Orange 2g
Pear 2g
Prunes (1/4 cup) 1.5 g
Reader's Digest Magic Foods for Better Blood Sugar