Living Low Carb (24 page)

High Protein Causes Kidney Disease? Not.

The oft-repeated medical legend that high-protein diets cause kidney disease came from reversing a medical fact. The medical fact is that reducing protein (up to a point) lessens the decline of renal (kidney) function in people who already have kidney disease. Because restricting protein seems to be a good strategy for those with
existing
kidney failure (or even some kidney weakness), some people drew the illogical conclusion that the obverse must also be true—that large amounts of protein
lead
to kidney failure.

In any case, it is not proteins per se that cause problems, even for those who already have renal disease: it is the
glycolated
proteins (see
chapter 2
). These sugar-sticky proteins, you may remember, are the result of excess sugar in the blood bumping into protein molecules. These sugar-coated proteins are called AGES,
a
dvanced
g
lycolated
e
nd-products. The AGES themselves then stick together, forming even bigger collections of molecules, which are too large to pass through the filtering mechanisms of the
glomerulus
, the network of blood capillaries in the kidneys that acts as a filter for waste products from the blood. This reduces GFR (glomerular filtration rate), a measure of kidney function.

High protein intake
does not
cause this to happen in normally functioning kidneys. A recent study of 1,624 women enrolled in the Nurses’ Health Study concluded that “high protein intake was not associated with renal function decline in women with normal renal function.”
¹⁷
Another study in the
American Journal of Kidney Diseases
showed that protein intake had
no effect
on GFR in healthy male subjects.
¹⁸
And a third study in the
International Journal of Obesity
compared a high-protein with a low-protein weightloss diet and concluded that healthy kidneys adapted to protein intake and that the high-protein diet caused no adverse effects.
¹⁹

If you don’t currently have kidney disease, a low-carb diet is an ideal way to help control the blood-sugar levels that can eventually lead to kidney disease. Of course, just to be safe, check with your doctor to make sure you don’t have any undiagnosed kidney impairment; but if you don’t, you’re sure not going to develop it from being on a low-carb diet.

BOTTOM LINE

Higher protein intakes do not cause any damage whatsoever to healthy kidneys
.

MYTH #6: The Only Reason You Lose Weight on a Low-Carb Diet Is Because It’s Low in Calories

The short response to this myth is simple:
so what
?

This accusation—that low-carb diets work only because they are low in calories—is particularly amusing because it is never made against high-carb weight-loss diets that are
equally
low in calories. In fact, there is only a 121-calorie difference between the most stringent induction phase of the Atkins diet and the Dean Ornish ultra-low-fat diet. And after the first couple of weeks, when you get into the ongoing weight loss phase of Atkins, you’re actually consuming 354 calories
more
than you would be on the Dean Ornish diet and 165 calories
more
than you would be on Weight Watchers.
²⁰
Yet you never hear the establishment say that the Ornish low-fat diet works only because it’s low-calorie!

Look, on virtually every weight-loss diet in the world, you ultimately wind up consuming fewer calories than you did while you were putting on weight. I don’t care if the diet is low-fat, high-fat, low-carb, high-carb, vegetarian, Food Guide Pyramid, raw food, you name it—ultimately, they are
all
reduced-calorie diets. One of the primary reasons most of them fail is hunger. By now, we know that insulin is called the hunger hormone for a very good reason, and insulin is elevated
most
by high-carbohydrate diets. So if you have a choice of gritting your teeth and staying on a 1,200-calorie, lowfat, high-carbohydrate diet that leaves you hungry and craving sweets all the time—or of going on a diet with the
same number of calories
that allows you to eat rich, satisfying, natural foods and doesn’t leave you hungry all the time, which would
you
pick?

Exactly. That’s why the short answer to this myth is “Who cares?” Even if it were true that low-carb diets work only because they are low-calorie, who gives a rat’s tail? If two “diets” with an equal number of calories produce equal weight loss but one is easier to stay on, why in the world wouldn’t you go with it?

More Food on a Low-Carb Diet?

Because a low-carbohydrate diet is able to reduce insulin levels and is far more likely to induce hormonally balanced states than conventional highcarb diets, it is possible—though we’re not 100% sure—that you may be able to consume somewhat more calories on a low-carb diet than you would on a high-carb diet and still lose weight. One dramatic study compared a low-fat diet to an Atkins-type diet in two groups of overweight adolescent boys. After three months, the low-carb group lost more than twice as much weight as the low-fat group (19 pounds for the low-carb group and 8.5 pounds for the low-fat group); the low-fat group averaged 1,100 calories a day, while the Atkins group averaged 1,803!
²¹

Recently, a number of studies have come out showing that weight loss is actually greater on a low-carb diet than on a conventional low-fat diet that has the same number of calories.
²²
To be fair, there are plenty of studies showing that both diets produce identical weight loss. (Interestingly, there are virtually
no
studies that show that low-carb diets produce
less
weight loss!) But even in the studies that show identical weight loss, triglycerides and HDL levels almost always improve on the higher-protein diets. For example, Alain Golay, a respected researcher who is no particular advocate of low-carb diets, recently tested a low-carb (25%) diet against a typical higher-carb (45%) diet for weight loss and found that, while there was not much difference in weight loss, the low-carb group had significantly greater improvements in fasting insulin and triglycerides.
²³
In another study, he pitted a low-carb (15%) diet against a higher-carb (45%) diet and again found similar weight loss but marked improvements in glucose, insulin, cholesterol, and triglycerides on the low-carb diet
only
; no such benefits were seen on the high-carb diet.
²⁴
If two “diets”—high-protein/low-carb and high-carb/lowfat—are equal in calories and produce equal weight loss but the first produces significantly improved blood chemistry and lowers the risk for heart disease and diabetes, why in the world wouldn’t you choose that one?

Many studies have been done comparing all kinds of different diets for weight loss; but the truth is that very few studies have lasted more than a year, leading many experts to conclude that while you can basically lose weight on any diet, we really have no idea whether any particular regimen is easier to stay on over the long haul. The action is clearly in
maintaining
weight loss, and since the lower-carb diets seem to be much more satiating, we can speculate that they may turn out to be a lot easier to maintain as a lifestyle than a diet that simply reduces fat, which is turning out to be a lot less important than previously thought. In fact, Dr. Walter Willett, chairman of the Department of Nutrition at Harvard University’s School of Public Health and one of the most respected researchers in the field, recently declared in two articles—one in
Obesity Reviews
²⁵
and one in the
American Journal of Medicine
²⁶
—that dietary fat is
not
a major determinant of body fat and plays virtually no role in obesity.

What about Calories?

Since most low-carb-diet authors do not advocate counting calories (at least at first) and because most low-carb diets are based on the premise that it is critical to control the hormonal responses to food, many people have gotten the idea that low-carb theorists think calories don’t matter at all. This is simply not so. As I wrote in a previous book, calories are still on the marquee; it’s just that they are not the starring players anymore. Of
course
calories still count—there isn’t a responsible low-carb diet writer out there who would argue the point. But controlling hormones counts
at least as much
, if not more. If I take in 1,500 calories a day from sugar and insulin-raising carbohydrates, I will find it notoriously difficult to lose any weight, since the high levels of insulin I produce are going to effectively block fat from being released from my fat cells. Yet if I take in the same 1,500 calories—or even a few more!—from a diet with fewer carbs and more protein and fat, the resulting balance between insulin and glucagon is going to be much more favorable to fat “burning.” And I’m likely to lose a lot more weight for the same caloric price.

On the other hand, to play devil’s advocate, if I take in 15,000 calories, all from fat with a little protein, producing the absolute minimum amount of insulin, I’m
still
going to gain weight. Why? Because even though the “doors” to the fat cells are now open for business, there is simply no reason for my body to
release
any of the fat inside them for fuel, because I’m already consuming way more fuel than I could possibly need.

Now, can you lose weight on a low-calorie diet that is not low-carb? Of course you can. People do it all the time. But consider the following: most weight-loss diets—of any kind—wind up being lower in carbohydrates
even if they are not “low-carb” diets
. The average overweight American man is easily able to consume 3,500 calories daily, and let’s hypothetically say 65% of it is from carbs. That’s a total of 2,275 calories from carbs, or 569 grams of carbohydrates a day. The National Weight Control Registry, which follows people who have successfully lost at least 30 pounds and kept it off for more than a year, has found that the average man on a successful weight maintenance diet consumes 1,724 calories, of which 56% come from carbohydrates.
²⁷
So our typical National Weight Control Registry man is consuming 237 grams of carbs a day,
a 59% reduction in carbohydrates from what he was eating when he put the weight on!

The average successful
woman
on the registry maintains her weight at 1,297 calories, 55% from carbohydrates.
²⁸
We can postulate that if she was 50 pounds overweight to begin with, she was eating
at least
2,000 calories a day minimum (probably more), and even if only 60% of that came from carbs, that’s 300 grams of carbs a day. At her present maintenance level, she’s consuming 178 grams, a 41% reduction in carb intake, certainly enough to make a major impact on insulin levels.

Yes, calories count. But so do hormones, and way more than the dietary establishment believes.

BOTTOM LINE

Calories count, but so do hormones. Many studies show more weight lost on low-carb diets than on high-carb diets with the same number of calories, and more of that weight comes from fat. Even those studies that show equal weight loss invariably show better blood chemistry on the low-carb diets. Lowering fat in the diet is not the answer to obesity.

MYTH #7: Low-Carb Diets Increase the Risk for Heart Disease

In Denmark, the number of storks is positively correlated with the number of babies born.

This interesting fact was taught to me in graduate school by a wonderful psychology professor named Dr. Scott Fraser, who used it to teach a lesson about scientific studies that has allowed me to understand a great many things about research. I will pass it on to you, and you may never look at research studies in quite the same way.

So let’s repeat: in Denmark, the more storks, the more babies. This positive correlation holds up year in and year out.

Okay, class, what shall we conclude from this?

I hope you see what I’m getting at.

Here’s what’s
actually
going on. In the particular part of Denmark where the study was done, single people live mainly in the cities. When they get married and decide to raise a family, they move to the suburbs. The architectural design of the suburbs in Denmark favors angled roofs made of tar. Storks nest in angled roofs made of tar. Both storks and young married couples wanting to have children gravitate to the same area, albeit for somewhat different reasons.

But they are
found together
, consistently, year after year. They are
positively correlated
.

The lesson:
correlation
does not equal
causation.
When two variables are found together, it does not mean that one caused the other. Diabetes went way up during the Clinton presidency, so an increase in diabetes is positively correlated with the Clintons. Statistical studies have also noted that the number of new radio and television sets purchased correlates with an increased number of deaths from coronary disease.
²⁹
In Stockholm, Sweden, there was a correlation between the municipal tax rate and coronary mortality, leading to the interesting proposition that if tax rates were lowered, there would be less heart disease!
³⁰