Good Calories, Bad Calories (2 page)

Foods to be avoided:

1. Bread, and everything else made with flour…

2. Cereals, including breakfast cereals and milk puddings

3. Potatoes and al other white root vegetables

4. Foods containing much sugar

5. Al sweets…

You can eat as much as you like of the following foods:

1. Meat, fish, birds

2. Al green vegetables

3. Eggs, dried or fresh

4. Cheese

5. Fruit, if unsweetened or sweetened with saccharin, except bananas and grapes

“The great progress in dietary control of obesity,” wrote Hilde Bruch, considered the foremost authority on childhood obesity, in 1957, “was the recognition that meat…was not fat producing; but that it was the innocent foodstuffs, such as bread and sweets, which lead to obesity.”

The scientific rationale behind this supposed cause and effect was based on observation, experimental evidence, and maybe the col ected epiphanies and anecdotes of those who had successful y managed to bant. “The overappropriation of nourishment seen in obesity is derived in part from the fat ingested with the food, but more particularly from the carbohydrates,” noted James French in 1907 in his Textbook of the Practice of Medicine. Copious opinions were offered, but no specific hypotheses. In his 1940 monograph Obesity and Leanness, Hugo Rony, director of the Endocrinology Clinic at the Northwestern University Medical School in Chicago, reported that he had careful y questioned fifty of his obese patients, and forty-one professed a “more or less marked preference for starchy and sweet foods; only 1 patient claimed preference for fatty foods.” Rony had one unusual patient, “an extremely obese laundress,” who had no taste for sweets, but “a craving for laundry starch which she used to eat by the handful, as much as a pound a day….” So maybe carbohydrates are fattening because that’s what those with a tendency to gain weight eat to excess.

To others, carbohydrates carry some inherent quality that makes them uniquely fattening. Maybe they induce a continued sensation of hunger, or even a specific hunger for more carbohydrates. Maybe they induce less satiation per calorie consumed. Maybe they somehow cause the human body to preferential y store away calories as fat. “In Great Britain obesity is probably more common among poor women than among the rich,” Sir Stanley Davidson and Reginald Passmore wrote in the early 1960s in their classic textbook Human Nutrition and Dietetics, “perhaps because foods rich in fat and protein, which satisfy appetite more readily than carbohydrates, are more expensive than the starchy foods which provide the bulk of cheap meals.”

This belief in the fattening powers of carbohydrates can be found in literature as wel . In Tolstoy’s Anna Karenina, for instance, written in the mid-1870s, Anna’s lover, Count Vronsky, abstains from starches and sweets in preparation for what turns out to be the climactic horse race. “On the day of the races at Krasnoe Selo,” writes Tolstoy, “Vronsky had come earlier than usual to eat beefsteak in the officers’ mess of the regiment. He had no need to be in strict training, as he had very quickly been brought down to the required weight of one hundred and sixty pounds, but stil he had to avoid gaining weight, and he avoided starchy foods and desserts.” In Giuseppe di Lampedusa’s The Leopard, published in 1958, the protagonist, Prince Fabrizio, expresses his distaste for the plump young ladies of Palermo, while blaming their condition on, among other factors, “the dearth of proteins and the overabundance of starch in the food.”

This was what Dr. Spock taught our parents and our grandparents in the first five decades, six editions, and almost 50 mil ion copies of Baby and Child Care, the bible of child-rearing in the latter half of the twentieth century. “Rich desserts,”

Spock wrote, and “the amount of plain, starchy foods (cereals, breads, potatoes) taken is what determines, in the case of most people, how much [weight] they gain or lose.” It’s what my Brooklyn-born mother taught me forty-odd years ago. If we eat too much bread or too much spaghetti, we wil get fat. The same, of course, is true of sweets. For over a century, this was the common wisdom. “Al popular ‘slimming regimes’ involve a restriction in dietary carbohydrate,” wrote Davidson and Passmore in Human Nutrition and Dietetics, offering this advice: “The intake of foods rich in carbohydrate should be drastical y reduced since over-indulgence in such foods is the most common cause of obesity.” “The first thing most Americans do when they decide to shed unwanted pounds is to cut out bread, pass up the potatoes and rice, and cross spaghetti dinners off the menu entirely,” wrote the New York Times personal-health reporter, Jane Brody, in her 1985 best-sel ing Good Food Book.

But by that time there had been a sea change. Now even Brody herself was recommending a diet rich in potatoes, rice, and spaghetti for the same purpose. “We need to eat more carbohydrates,” Brody declared. “Not only is eating pasta at the height of fashion…. It can help you lose weight.” The carbohydrate had become heart-healthy diet food. Now it was the butter rather than the bread, the sour cream on the baked potato that put on the pounds. The bread and the potato themselves were no longer the cause of weight gain but the cure. When a committee of British authorities compiled their “Proposals for Nutritional Guidelines for Health Education in Britain” in 1983, they had to explain that “the previous nutritional advice in the UK to limit the intake of al carbohydrates as a means of weight control now runs counter to current thinking….”

This was one of the more remarkable conceptual shifts in the history of public health. As clinical investigators were demonstrating the singular ability of carbohydrate-restricted diets to generate significant weight loss without hunger,*3 the mainstream medical establishment was insisting, as in a 1973 editorial by the American Medical Association, that the diets were dangerous fads—“bizarre concepts of nutrition and dieting [that] should not be promoted to the public as if they were established scientific principles.”

Just four months after the AMA publicly censured the use of these diets in The Journal of the American Medical Association, obesity researchers from around the world gathered in Bethesda, Maryland, for the first conference on obesity ever hosted by the National Institutes of Health. The only talk on the dietary treatment of obesity was presented by Charlotte Young, a wel -known dietitian and nutritionist at Cornel University who had been studying and treating obesity for twenty years.

Young first discussed the work of Margaret Ohlson, chair of nutrition at Michigan State University, who had tested carbohydrate-restricted diets in the early 1950s. “The diets developed by Ohlson,” reported Young, “gave excel ent clinical results as measured by freedom from hunger, al aying of excessive fatigue, satisfactory weight loss, suitability for long term weight reduction and subsequent weight control.” She then presented the results of her research at Cornel , testing Banting-like diets on overweight young men. As in the other reports over the last century, she noted, her subjects seemed to lose weight by restricting only sugars and starches, without feeling any particular sense of hunger. Moreover, the less carbohydrates in their diets, the greater their weight loss, even though al her subjects were eating equivalent amounts of calories and protein. “No adequate explanation could be given,” Young reported, implying that further scientific research might be important to clarify this issue.

None would be forthcoming, and a century of empirical evidence would be rendered irrelevant, as the AMA’s spin on Banting’s low-carbohydrate diet as fad was quickly adopted as the conventional wisdom, one that has been adhered to faithful y ever since. Dietary fat had been identified as a probable cause of heart disease, and low-fat diets were now being advocated by the American Heart Association as the means of prevention. At the same time, the low-fat diet as the ideal treatment for weight loss was adopted as wel , even though a low-fat diet was, by definition, high in the very carbohydrates that were once considered fattening.

This transformation is al the more remarkable because the medical authorities behind it were concerned with heart disease, not obesity. They presented no dramatic scientific data to support their beliefs, only ambiguous evidence, none of which addressed the efficacy of low-fat diets in weight loss. What they did have was the diet-heart hypothesis, which proposed that the excessive consumption of fat in our diets—particularly saturated fats—raises cholesterol levels and so causes atherosclerosis, heart disease, and untimely death. The proponents of this theory believed that Americans—and later the entire developed world—had become gluttons. Americans ate too much of everything—particularly fat—because we could afford to, and because we could not or would not say no. This overnutrition was certainly the cause of obesity. Eating too many calories was the problem, and since fat contains more than twice as many calories per gram as either protein or carbohydrates, “people who cut down on fat usual y lose weight,” as the Washington Post reported in 1985.

A healthy diet, by definition, had suddenly become a low-fat diet. Beginning in the late 1980s with publication of The Surgeon General’s Report on Nutrition and Health, an entire research industry arose to create palatable nonfat fat substitutes, while the food industry spent bil ions of dol ars marketing the less-fat-is-good-health message. The U.S. Department of Agriculture’s (USDA’s) booklet on dietary guidelines, and its ubiquitous Food Guide Pyramid, recommended that fats and oils be eaten “sparingly,” while we were now to eat six to eleven servings per day of the pasta, potatoes, rice, and bread once considered uniquely fattening.

The reason for this book is straightforward: despite the depth and certainty of our faith that saturated fat is the nutritional bane of our lives and that obesity is caused by overeating and sedentary behavior, there has always been copious evidence to suggest that those assumptions are incorrect, and that evidence is continuing to mount. “There is always an easy solution to every human problem,” H. L. Mencken once said—“neat, plausible, and wrong.” It is quite possible, despite al our faith to the contrary, that these concepts are such neat, plausible, and wrong solutions. Moreover, it’s also quite possible that the low-fat, high-carbohydrate diets we’ve been told to eat for the past thirty years are not only making us heavier but contributing to other chronic diseases as wel .

Consider, for instance, that most reliable evidence suggests that Americans have indeed made a conscious effort to eat less fat, and particularly less saturated fat, since the 1960s. According to the USDA, we have been eating less red meat, fewer eggs, and more poultry and fish; our average fat intake has dropped from 45 percent of total calories to less than 35 percent, and National Institutes of Health surveys have documented a coincident fal in our cholesterol levels. Between 1976

and 1996, there was a 40-percent decline in hypertension in America, and a 28-percent decline in the number of individuals with chronical y high cholesterol levels. But the evidence does not suggest that these decreases have improved our health.

Heart-disease death rates have indeed dropped over those years. The risk of suffering a severe heart attack, what physicians cal an acute myocardial infarction, may have diminished as wel . But there is little evidence that the incidence of heart disease has declined, as would be expected if eating less fat made a difference. This was the conclusion, for instance, of a ten-year study of heart-disease mortality published in The New England Journal of Medicine in 1998, which suggested that the death rates are declining largely because doctors and emergency-medical-service personnel are treating the disease more successful y. American Heart Association statistics support this view: between 1979 and 2003, the number of inpatient medical procedures for heart disease increased 470 percent. In 2003 alone, more than a mil ion Americans underwent cardiac catheterizations; more than a quarter-mil ion had coronary-artery bypass surgery.

The percentage of Americans who smoke cigarettes has also dropped considerably over the years—from 33 percent of Americans over eighteen in 1979 to 25 percent fifteen years later. This should also have significantly reduced the incidence of heart disease. That it hasn’t, strongly suggests we’re doing something that counteracts the beneficial effect of giving up cigarettes. Indeed, if the last few decades were considered a test of the fat-cholesterol hypothesis of heart disease, the observation that the incidence of heart disease has not noticeably decreased could serve in any functioning scientific environment as compel ing evidence that the hypothesis is wrong.

Throughout the world, on the other hand, the incidence of obesity and diabetes is increasing at an alarm in grate. Obesity levels in the United States remained relatively constant from the early 1960s through 1980, between 12 and 14 percent of the population; over the next twenty-five years, coincident with the official recommendations to eat less fat and so more carbohydrates, it surged to over 30 percent. By 2004, one in three Americans was considered clinical y obese. Diabetes rates have increased apace. Both conditions are associated with an increased risk of heart disease, which could explain why the incidence of heart disease is not decreasing. It is also possible that obesity, diabetes, and heart disease al share a single, underlying cause. The surge in obesity and diabetes occurred as the population was being bombarded with the message that dietary fat is dangerous and that carbohydrates are good for the heart and for weight control. This suggests the possibility, however heretical, that this official embrace of carbohydrates might have had unintended consequences.

I first heard this notion in 1998, when I interviewed Wil iam Harlan, then associate director of the Office of Disease Prevention at the National Institutes of Health. Harlan told me that public-health experts like himself assumed that if they advised al Americans to eat less fat, with its densely packed calories, weights would go down. “What we see instead,” he said, “is actual y weights have gone up, the portion sizes have gone up, the amount we eat has gone up…. Foods lower in fat became higher in carbohydrates and people ate more.”