Why We Get Fat: And What to Do About It (28 page)

This is not a diet book, because it’s not a diet we’re discussing. Once you accept the fact that carbohydrates—not overeating or a sedentary life—will make you fat, then the idea of “going on a diet” to lose weight, or what the health experts would call a “dietary treatment for obesity,” no longer holds any real meaning. Now the only subjects worth discussing are how best to avoid the carbohydrates responsible—the refined grains, the starches, and the sugars—and what else we might do to maximize the benefits to our health.

Since the 1950s, some very thoughtful diet books have advocated that we restrict carbohydrates to control our weight, and these books have been appearing ever more frequently in recent years. Initially the authors were physicians, typically with weight problems themselves. This made their experiences similar: they failed to lose weight by eating less or exercising but eventually came upon the idea of restricting carbohydrates. They tried it, found that it worked, and prescribed it to their patients. Then they wrote books based on their experiences, both to get the message out and also to profit from whatever they considered their personal contribution to the genre. The books sold at first because the regimens worked and because there are always people who will try any new diet if they think it might work.

Eat Fat and Grow Slim
(1958),
Calories Don’t Count
(1960),
Dr. Atkins’ Diet Revolution
(1972),
The Carbohydrate Addict’s Diet
(1993),
Protein Power
(1996), and
Sugar Busters!
(1998) are all
best-selling variations on the same theme: refined carbohydrates, starchy vegetables, and sugars are fattening; don’t eat them, don’t drink them.
^*
These books are worth reading for the guidance they offer. But the diets themselves, no matter how they vary in the details or the author’s understanding of the underlying science, fundamentally work because they restrict fattening carbohydrates.

In the
appendix
I have given a pared-down version of the kind of dietary guidelines that can be found in many books that would be classified as “low-carbohydrate” diets in bookstores or on websites. My directives are borrowed from the Lifestyle Medicine Clinic at the Duke University Medical Center (which in turn adapted them from the Atkins Center for Complementary Medicine). The clinic is run by Eric Westman, a physician who became intrigued by the diet in 1998, after one of his patients lost twenty pounds in two months and insisted he did so by eating large quantities of steak and little else. Westman responded by reading up on the Atkins diet, meeting with its author, Robert Atkins, in New York, and asking Atkins to fund a small pilot study (fifty patients, six months) to determine whether the diet works and is safe. The results confirmed that patients could lose weight and improve their cholesterol profiles on diets of virtually nothing but meat and leafy green vegetables.

Westman then visited physicians who were already using Atkins’s diet in their clinics—Mary Vernon in Lawrence, Kansas; Richard Bernstein in Mamaroneck, New York; Joseph Hickey in Hilton Head, South Carolina; and Ron Rosedale in Boulder, Colorado—and reviewed their charts to verify that what Atkins was saying, and Westman’s pilot study had concluded, actually
held up in clinical practice. In 2001, Westman began treating overweight and obese patients with the diet, and he’s done so ever since. He has also continued to run clinical trials that have so far confirmed the health benefits of the diet—both in diabetics and in those without diabetes. (Westman is also an author, along with Stephen Phinney of the University of California, Davis, and Jeff Volek of the University of Connecticut, of the 2010 version of the Atkins diet book,
The New Atkins for a New You.
)

The guidelines that Westman distributes to his patients are more detailed but otherwise little different from the guidance offered by hospitals to their overweight and obese patients in the late 1940s and 1950s: Eat as much as you like of meat, fish, fowl, eggs, and leafy green vegetables. Avoid starches, grains, and sugars and anything made from them (including bread, sweets, juices, sodas), and learn for yourself whether and how much fruit and non-starchy vegetables (such as peas, artichokes, and cucumbers) your body can tolerate. If these concepts are familiar ones and the details are unnecessary, then I recommend taking the diet for obesity from Raymond Greene’s 1951 endocrinology textbook,
The Practice of Endocrinology
, which I present on
this page
and
this page
, and taping it to your refrigerator to refer to as necessary. If you need more details about which foods are acceptable and which are not, then the appendix is the better choice.

It would be nice if we could improve on the list of foods to eat, foods to avoid, and foods to eat in moderation. Unfortunately, this can’t be done without guessing. The kind of long-term clinical trials have not been undertaken that would tell us more about what constitutes the healthiest variation of a diet in which the fattening carbohydrates have already been removed. We know from clinical trials that carbohydrate-restricted, eat-as-much-as-you-like diets work and that they have the expected beneficial effects on metabolic syndrome and thus our risk of heart disease. But that’s the extent of the reliable knowledge so far.

What we have instead as a guide is the science itself—Adiposity 101—and the clinical experience of physicians like Westman who
have had enough faith in their own observations and their understanding of the science to wean their overweight, obese, and diabetic patients off fattening carbohydrates, despite having to go against established convention to do so. From the experience of these physicians—Mary Vernon, Stephen Phinney, Jay Wortman of the University of British Columbia, and Michael and Mary Dan Eades, authors of
Protein Power
—I can offer a few thoughts on some of the obvious questions that are raised when we consider trading off fattening carbohydrates for a healthier and leaner life.

The fewer carbohydrates we consume, the leaner we will be. This is clear. But there’s no guarantee that the leanest we
can
be will ever be as lean as we’d like. This is a reality to be faced. As I discussed, there are genetic variations in fatness and leanness that are independent of diet. Multiple hormones and enzymes affect our fat accumulation, and insulin happens to be the one hormone that we can consciously control through our dietary choices. Minimizing the carbohydrates we consume and eliminating the sugars will lower our insulin levels as low as is safe, but it won’t necessarily undo the effects of other hormones—the restraining effect of estrogen that’s lost as women pass through menopause, for instance, or of testosterone as men age—and it might not ultimately reverse all the damage done by a lifetime of eating carbohydrate- and sugar-rich foods.

This means that there’s no one-size-fits-all prescription for the quantity of carbohydrates we can eat and still lose fat or remain lean. For some, staying lean or getting back to being lean might be a matter of merely avoiding sugars and eating the other carbohydrates in the diet, even the fattening ones, in moderation: pasta dinners once a week, say, instead of every other day. For others, moderation in carbohydrate consumption might not be sufficient,
and far stricter adherence is necessary. And for some, weight will be lost only on a diet of virtually zero carbohydrates, and even this may not be sufficient to eliminate all our accumulated fat, or even most of it.

Whichever group you fall into, though, if you’re not actively losing fat and yet want to be leaner still, the only viable option (short of surgery or the prospect that the pharmaceutical industry will come through with a safe and effective anti-obesity pill) is to eat still fewer carbohydrates, identify and avoid other foods that might stimulate significant insulin secretion—diet sodas, dairy products (cream, for instance), coffee, and nuts, among others—and have more patience. (Anecdotal evidence suggests that occasional or intermittent fasting for eighteen or twenty-four hours might work to break through these plateaus of weight loss, but this, too, has not been adequately tested.)

Physicians who have treated patients by prescribing carbohydrate-restricted diets for a decade or longer and published discussions of their clinical experiences—the British physician Robert Kemp, for instance, who began doing so in 1956, and Wolfgang Lutz, an Austrian physician, who began a year later—have reported that a small proportion of their obese patients failed to lose any significant fat even though they faithfully avoid fattening carbohydrates (or at least said they did). Women failed more often than men, and older patients more often than younger ones. The more obese the patients, and the longer they had been obese, the more likely they were to remain obese.
^*
However, as Lutz said, this doesn’t mean “that the carbohydrates were not responsible for the disorder [obesity] in the first place. It is quite simply, and sadly, that a point of no return has been reached.”

What we don’t know is whether these individuals could have succeeded had they further restricted carbohydrates, or had they simply had more patience, and maybe both. The conventional logic of diets is that people go on them expecting relatively quick returns in weight loss. By this logic, the dieters are not trying to reregulate their fat tissue; they’re only reducing the calories they consume, with the expectation that their fat cells will willingly respond by giving up the calories they’ve sequestered. If dieters see no significant losses in a month or two, they decide that the diet has failed and either move to the next one or resign themselves to their adiposity. But the fact is that we
are
trying to counteract a regulatory disorder of fat metabolism, one that may have been years or decades in the making. Reversing the process might take more than a few months or even a few years as well.

Carbohydrate restriction is often equated with eating animals and animal products. The reason is simple: if you eat mostly plants or exclusively plants, you’re getting the bulk of your calories from carbohydrates, by definition. This doesn’t mean that you can’t become lean or remain lean by giving up sugars, flour, and starchy vegetables, and living exclusively on leafy green vegetables, whole grains, and pulses (beans). But it is unlikely to work for many of us, if not most. Leafy green vegetables and pulses have the advantage that the carbohydrates they contain aren’t digested quickly—they have what nutritionists call a low glycemic index—but if you’re relying on these foods for the bulk of your diet, then the total amount of carbohydrates you’re consuming (the glycemic load of your diet) will still be high. This may be enough either to make you fat or to keep you fat. If you try to eat fewer carbohydrates by eating smaller portions, you’ll be hungry, with all the problems that entails.

So if you are a vegan or a vegetarian you can still benefit from an understanding of Adiposity 101. You can always improve the quality of the carbohydrates you eat, even if you don’t reduce the
total quantity. This change alone will assuredly improve your health, even if it’s not sufficient to make you lean.

Over the years, the physicians promoting carbohydrate restriction have typically taken one of three approaches to maximizing the effect and the sustainability (equally important) of this manner of eating.

One is to establish an ideal amount of carbohydrates that you can and perhaps should eat—say, the seventy-two grams a day, or nearly three hundred calories’ worth, that Wolfgang Lutz prescribes. This is intended to minimize any potential side effects that might occur when the body makes the transition from burning primarily carbohydrates for fuel to burning fat. The approach also assumes that it’s easier to eat some fattening carbohydrates than it is to eliminate them entirely. With this logic, Lutz allows “small amounts of sugar and an occasional dessert, some crumbs for breaded food, a little lactose (in milk), and small quantities of carbohydrate in vegetables and fruit.” This may work for some of us but not for all.

Another approach is to aim for minimal carbohydrates from the outset. You don’t need them in your diet, so this logic goes, and any short-term side effects you might experience while your body adjusts to a nearly carbohydrate-free diet can be managed (more on that).

The third option is a compromise that was pioneered by Robert Atkins forty years ago. It was based on what seems like an obvious point to make (although not so obvious that the health experts today tend to make it): You enter into a weight-loss diet with the singular purpose of becoming as lean as you safely can be, and so all other gustatory desires should be put on hold
temporarily
until that goal is achieved. When you have achieved your goal and the excess fat has been lost, you can decide if you feel the
need to incorporate back into your diet some of the foods you’ve been avoiding.

Diets that operate on this philosophy typically begin with what Atkins called an “induction phase,” which allows effectively no carbohydrates (fewer than twenty grams a day in Atkins’s diet). This has the effect of accelerating initial weight loss and providing encouragement to stick with the diet. You’re instructed to give up all carbohydrates, with the sole exception of a few small portions of leafy green vegetables each day. Once your body is actively engaged in burning its own fat stores and you’re losing weight at an acceptable pace, a minimal amount of carbohydrates can be added back into the diet. If, however, you stop losing fat, that means your body can’t tolerate these carbohydrates and you can’t eat them.

The same approach can be used once an ideal weight is reached. Add back whatever carbohydrate-rich foods you particularly miss and see how your body responds. If you begin to gain weight, say, because you’re now eating an apple a day, and you don’t want to be any heavier, then don’t eat the apple. If you don’t gain weight, that means your body can tolerate an apple a day, and you can experiment with other carbohydrates. You can see what happens when you also eat an orange a day or a pasta dinner once a week or the occasional dessert. This allows you to determine what your body can tolerate and how much fat you’re willing to accommodate for the foods you miss.