Read an Excerpt
Why Are We Doing This, Anyway?
The Basic Idea
The objective of all low-carb diets, which date back at least to the early nineteenth century, has always been weight loss. Although plenty of low-fat advocates continue to insist that it's only water that's lost on a low-carb regimen, many patients using it have lost over 100 pounds in short order. Among the many formerly obese, it's pretty well agreed that low-carb is the most effective, most enjoyable, and most successful over the long term of all the various diets. Despite our government's dictate that we load up on carbs to maintain our health, low-carb books have consistently topped the bestseller charts for nearly a decade. Literally millions of people have followed these diets with no reported ill effects so far. Although low-carb diets are still controversial within the health establishment, they have never been vulnerable to charges like the deaths that have been associated with fen-phen or liquid diets. The theoretical argument will continue to rage, and it's extremely unlikely that any definitive studies will be done anytime soon to settle it.
Why do these low-carb diets work so well when almost nothing else does? For a long time the exact mechanisms weren't clearly understood, but when Drs. Michael and Mary Dan Eades (authors of Protein Power) went back to their basic biochemistry texts, they discovered not only the weight-loss mechanism but also the huge number of health benefits that can accrue to many who follow the low-carb path. These include dramatically lowering high blood pressure, levelsof the dangerous blood fats called triglycerides, and LDL (bad) cholesterol; controlling diabetes; supplying extra energy throughout the entire day with no up-and-down swings; increasing concentration and focus; enhancing lean body mass with loss of excess body fat; improving immune function; eliminating gout and esophageal reflux; and many other benefits, such as a reversal of inflammatory conditions.
All this happens, the experts in the area now agree, because restricting carbohydrates sugar and starch in whatever form, from Popsicles to baked potatoes puts the brakes on insulin, the hormone that's responsible not only for storing fat (and worse, keeping it stored) but also for raising blood pressure, damaging blood vessels, and wreaking other bits of havoc throughout the body for those of us who are genetically predisposed to obesity, diabetes, and heart disease. Incoming sugars and starches require insulin the more sugar you consume, the more insulin is needed to process it at the cellular level. After an individual has been on a steady high-sugar diet over a number of years, the insulin receptors on his or her cells may become resistant, in which case even more insulin is required to handle the sugar load. Such a person usually develops insulin resistance, sometimes called Syndrome X or hyperinsulinemia, which usually leads to Type II (adult-onset) diabetes. An insulin-resistant person usually has an increased waist-to-hip ratio, high blood glucose levels, high uric acid, high triglycerides, and low HDL (the good cholesterol). There seems to be a genetic propensity to have problems with insulin. If your family tends to gain weight easily, especially in the abdominal area, you probably have this syndrome, and are therefore at risk for the related health problems (if you don't already have them) unless you change your diet.
The only way to cut back on this outpouring of insulin is by reducing your intake of carbohydrates. Since you always need the same amount of protein, no matter what diet you're on about 0.5 gram for every pound of your ideal weight you'll obviously eat more fat on a low-carb diet. (Remember, there are only three food groups to choose from: protein, fat, and carbohydrate.) A number of low-carb diets feature enormous amounts of steak, cheese, butter, and cream, and many anecdotal tales tell of people consuming up to 3,000 calories a day on such a regime and still continuing to lose weight. Other low-carb diets limit the consumption of fats, or vary the ratios of the kinds of fats consumed.
So, do calories not count? They do and they don't. If you don't have insulin problems and have a normal metabolism but simply eat too much, you can go by the standard advice: Cut calories and you will lose weight. But if you do have genetic insulin problems, as you probably do if you're from an overweight family, you may not fare as well on a reduced-calorie diet unless you also cut the carbs very far back. Except for the amazing tales of the 3,000-calorie dieters, though, there's no free lunch on a low-carb diet: If you want to lose a substantial amount of weight, you still need to create a caloric deficit, though perhaps not such a dramatic one as if you weren't concentrating on cutting carbs.
Many people who aren't actually overweight adopt a low-carb diet for health reasons. Some of them are skinny but diabetic; others would prefer to attempt to control their cholesterol or blood pressure without dangerous and expensive medications. The muscular guys you see at the gym eat low-carb to build their lean body mass and minimize fat. Many children with epilepsy have for decades now been given a very successful treatment that involves a no-carb, high-fat diet not only has their epilepsy been controlled when medication has failed, they've suffered no ill effects from such a drastic regime.
The nutritional establishment's thinking on the subject of dietary fat has begun to change, partly because the low-fat prescription has had fairly unhappy results, such as continuing rampant obesity throughout the population and childhood diabetes increasing by 20 percent in the last decade. Fertility levels have fallen, which may also be a result of our not eating enough fat, and leading researchers such as Dr. Walter Willett of Harvard have started arguing that it's the kind of fat, not the total fat consumed, that makes the difference in weight gain. Willett is comfortable with a diet that's as high as 40 percent fats, as long as those fats are mainly unsaturated.
The fact is, we don't really know very much about human nutrition and metabolism, despite experts' having made claims for "the perfect diet" since the beginning of time. What our species actually evolved to eat, though, is quite like the low-carb diet: protein and fat from small animals and sea creatures and birds, small amounts of carbohydrate from plants and berries and seeds and nuts, and the occasional feast on a major animal. Dairy products are quite recent additions to the human diet, as are agricultural products, which we've had for only 10,000 years a minuscule amount of time, from an evolutionary standpoint. Many of us may simply not have adapted biologically to this relatively "new" diet, which may be one reason we feel so good and flourish so well on a low-carb plan.
Needless to say, there are many theories within the low-carb camp, and many different low-carb regimens. If you're seriously thinking about eating this way for the rest of your life as you should be if you have the insulin problem you ought to take a look at all of them and choose the one that seems best suited to you.