Good Calories, Bad Calories (111 page)

*65 The apparent severity of this epidemic is inflated by the way in which obesity is defined. The use of a threshold for establishing whether or not you’re obese—a body mass index (BMI) of 30—means that one can move from the overweight category to the obese category by virtue of gaining a few pounds. As a result, the 10-percent rise in obesity between 1991 and 2000 actual y represented an increase in the average BMI of Americans from 26.7

to 28.1, an average weight gain of seven to ten pounds.

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*66 Between the second and third National Health and Nutrition Examination Study.

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*67 The USDA has a variety of mechanisms for estimating macronutrient intake—i.e., protein, carbohydrates, and fat—and has published a variety of reports on the subject. Not al are consistent, but the findings on fat consumption are. For instance, in April 1998, the USDA published an article entitled

“Is Total Fat Consumption Real y Decreasing?” This article reported that average total fat consumption for men aged nineteen to fifty, for instance, dropped from 113 grams per day in 1977–78 to ninety-six in 1989, the period that encompasses the beginning of the obesity epidemic. The relevant numbers for women of the same age group are seventy-three grams of fat per day in 1977–78 and sixty-two in 1989.

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*68 According to the Sporting Goods Manufacturers Association, sales of sporting equipment, apparel, and shoes increased from $21.9 bil ion in 1987

(the earliest year for which they have data) to $52 bil ion in 2004.

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*69 If each Pima drank two eight-ounce soft drinks a day, this would add roughly two hundred calories a day to Hesse’s estimate of both carbohydrate and calorie consumption, and so would drop the fat in the diet to 22 percent.

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*70 The Sioux were “essential y carnivorous” prior to their reservation life, the report noted, and so they “were never in the habit of eating much fruit and vegetables.”

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*71 Hrdli ka did publish a list of diseases treated by the local agency physician, which did include one case of diabetes.

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*72 In 1804 and 1805, when the Corps of Discovery under Meriwether Lewis and Wil iam Clark made their historic overland expedition to the Pacific Ocean, they described game so plentiful in places that they literal y had to club it out of their way to make progress.

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*73 This conclusion was supported four years later, when German researchers published their protocol for keeping these desert sand rats healthy in captivity. “It is wel known that these animals wil develop diabetes mel itus soon after their natural vegetative diet is removed and replaced with standard laboratory rations,” they noted. But both diabetes and obesity can be avoided if the animals are reared on a suitable diet: in this case, fruits, vegetables, and herbs, supplemented by an unlimited supply of insects, shrimps, worms, and grasshoppers.

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*74 If the surgery is done to rodents during hibernation, they wil somehow slow the rate at which they draw on their fat supplies for fuel so as to compensate for the loss.

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*75 The diet constituted roughly 400 calories a day of protein, 270 calories of fat, and 900 calories of carbohydrates.

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*76 Though Stunkard’s analysis has widely been perceived as a condemnation of al methods of dietary treatment of obesity, the studies he reviewed included only semi-starvation, calorie-restricted diets.

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*77 Physical activity is the primary determinant of the variation in energy intake in human populations, as Walter Wil ett and his Harvard col eague Meir Stampfer note in the 1998 textbook Nutritional Epidemiology:“Indeed, in most instances, energy intake can be interpreted as a crude measure of physical activity….”

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*78 When Mayer wrote about this research, or when he spoke to reporters about it, he would often give the impression that it included multiple studies in animals and humans—“J. Mayer has since demonstrated, in both animal and human studies…,” as he would write in Science in 1967. This was technical y true, in that he had performed studies of both humans and animals—one study of each.

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*79 Tanner did believe that Wil iam Banting’s French predecessor Jean-François Dancel had final y provided a “more sure basis” for the treatment of obesity, and that Banting himself deserved credit for “bringing the subject before the public in a plain and sensible manner.”

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*80 It also assumes that the ingestion of food greater than that required by the body won’t lead to a compensatory increase in energy expenditure, which is a point we’l discuss at length in the next chapter.

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*81 This left von Noorden explaining that the detection of a retarded metabolism seemed to require “special knowledge and acumen on the part of the observer,” and he acknowledged that even he lacked sufficient expertise. Hence, the only way to diagnose a retarded metabolism was by implication: if the patient’s weight could not be “brought under control through intel igent regulation of diet and exercise,” then the patient probably had a retarded metabolism. The circularity of this argument was evidently not apparent to him.

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*82 This notion has survived in the suggestion that weight gain in children is exacerbated by the refusal of parents to al ow their children to walk or ride to school, for fear they wil be kidnapped or abused by strangers.

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*83 The common response to confronting this dilemma, as Bennett noted, “is to ignore it,” which is what happened to Bennett’s commentary, even though he discussed this issue at a 1986 obesity conference hosted by the New York Academy of Sciences and attended by many of the prominent authorities in the field.

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*84 That the toxic-environment hypothesis is deeply immersed in moral and class judgments is evidenced by the observation that few or none of the condemnations of fast-food restaurants include a coffee chain such as Starbucks, despite the copious excess calories it peddles. A “grande” (sixteen ounces) Tazo ® Chai Crème Frappuccino, ® for instance, with whipped cream has roughly 510 calories, equivalent to a quarter-pounder with cheese at McDonald’s. The same judgments are made when discussing physical activity: If we sit around al day watching television, we’re condemned as couch potatoes, and our obesity is only a matter of time. If we sit around studying or reading books, this same accusation is rarely voiced.

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*85 These observations do not contradict Magnus-Levy’s. Magnus-Levy compared lean and obese subjects. These latter observations compare those who gain weight to those who don’t; this difference, as we’l see, is critical.

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*86Obesity and Leanness was the first serious book on obesity published after 1900, when von Noorden published Die Fettsucht. In the years since, there have been only half a dozen similar attempts (out of the innumerable professional texts and proceedings now available) to present a comprehensive and balanced analysis of the evidence, and only three come close to Obesity and Leanness in critical analysis—the chapters on obesity and undernutrition in the 1933 English translation of Eric Grafe’s Metabolic Diseases and Their Treatment, Hilde Bruch’s Importance of Overweight, and, a distant fourth, John Garrow’s Energy Balance and Obesity in Man.

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*87 A hormone also secreted by the pancreas that tends to counteract the effects of insulin.

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*88 This phenomenon led to the notion of low-protein diets for weight loss. Regrettably, the ability to burn off excess calories when consuming a protein-deficient diet appears to be specific to young animals, and maybe even young pigs. When researchers tried to replicate this result in other animals—rats, sheep, cattle, or even older pigs—they noted that the animals eating the lower-protein diet got considerably fatter. They had more fat and less muscle, even if they weighed the same as the control animals.

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*89 Although, as we discussed in Chapter 16, the total energy expenditure of obese individuals is likely to be greater, because they have, simply put, more pounds to expend energy and generate heat.

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*90“The mean diet for Japanese people,” Nishizawa et al. reported, citing a 1972 survey by the Ministry of Health and Welfare, “consists of 359 g of carbohydrate, 50.1 g of fat, 82.9 g of protein and a total of 2,279 calories.”

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*91“Obesity itself,” as the National Academy of Sciences noted in 1989, “has not been found to be associated with dietary fat in either inter-or intra-population studies.”

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*92 The Duke University pediatrician James Sidbury, Jr., who would go on to become director of the National Institute of Child Health and Human Development, made the same observation about the obese children he treated in the early 1970s: “A pattern of constant nibbling was consistently found.

Most common snack foods are predominantly carbohydrate: crackers, potato chips, french fries, cookies, soft drinks, and the like.”

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†93 Evans’s first test diets “cal ed for no carbohydrate whatever” only later did he settle on twenty grams of carbohydrates to address nitrogen balance.

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*94“Wheat contains al of the essential amino acids,” explained the Columbia University nutritional anthropologist Marvin Harris, “but to get enough of the ones that are in scarce supply a man weighing 176 pounds (80 kilos) would have to stuff himself with 3.3 pounds (1.5 kilos) of whole wheat bread a day.

To reach the same safe level of protein, he would need only .75 pounds (340 grams) of meat.”

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*95 These included Graham Lusk and Eugene Du Bois from Cornel and the Russel Sage Institute of Pathology; Russel Pearl and Wil iam McCal um from Johns Hopkins; the Harvard anthropologist Earnest Hooton; and Clark Wissler of the American Museum of Natural History.

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*96 There are only four experiments in the medical literature, not including Stefansson and Anderson’s, in which the goal was to induce scurvy in human subjects—in one, four, twenty, and four subjects respectively. In each case, the goal was accomplished and the diets were carbohydrate-and/or sugar-rich.

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*97 According to Lewis Finn, then president of the Delaware Academy of Medicine, Gehrmann’s department at DuPont was “one of the most outstanding industrial medical departments in the country.”

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*98 One DuPont executive, discussed by Pennington in a later report, lost sixty-two pounds on the diet and kept it off for more than two years, while averaging thirty-three hundred calories of meat a day. If he ate any carbohydrates, “even an apple,” Pennington wrote, his weight would climb upward.

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*99 These critiques were written by anonymous “competent authorities.” In this case, the likely authority was Philip White, formerly at Harvard, now beginning his job as secretary of the AMA’s Council on Foods and Nutrition and a columnist for JAMA. He would write a similar dismissal of high-fat, carbohydrate-restricted diets under his own name in 1962, and then edit another anonymous version in 1973.

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*100 Ohlson worried that “the large servings of meat” could get monotonous and that the diet did not meet the recommended daily al owances for essential vitamins recently introduced by the Food and Nutrition Board of the National Research Council. She therefore included in her diet more milk, cheese, and eggs than Pennington had recommended, and expanded the choice of fruits and vegetables.

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*101 Drug studies were encouraged by the relative ease of obtaining money and resources from the pharmaceutical industry, and the absence of funding for dietary treatments.

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†102 In 1989, Wil iam Dietz, who now serves as director of the Division of Nutrition and Physical Activity at the Centers for Disease Control, reported that Bistrian and Blackburn’s diet was “especial y successful” on obese patients with a genetic disorder cal ed Prader-Wil i syndrome, “whose characteristic ravenous appetites appeared to be suppressed.”

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*103 When the authors included only randomized control trials in their calculations, they identified seven relevant studies of this severe carbohydrate restriction and seventy-five of higher-carbohydrate diets. The average weight loss was eight pounds for the carbohydrate-restricted diets and four for the higher-carbohydrate diets.

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*104 Indeed, the AMA’s 1973 critique escaped the issue of hunger by including “anorexia” as one of the “untoward side effects” of the diet. Since anorexia, in this context, is the technical term for loss of appetite, it seemed a peculiar criticism to make of a weight-loss diet.

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*105 The auxiliary “may” is critical here, because Yudkin based his conclusions on three-day dietary records, which are notoriously inaccurate. He then assumed that these three-day records could be extrapolated to the entire two weeks of the study, and from there to what would happen over months or years on the diet.

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*106 When Ted Van Ital ie, who worked with Jean Mayer in the 1950s, was asked why Mayer paid so little attention to the prewar German literature on obesity, he said, “Mayer hated the Germans. He shot a few of them in World War I .”

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*107 Brobeck paired each of a dozen lesioned rats with a healthy control rat and fed the lesioned rat precisely the same amount of food that the control rat had consumed on the previous day. “In three pairs of animals,” Brobeck wrote, “the rat with lesions gained more rapidly than the control when they were fed the same amount of food.” Thus overeating could not be the cause of the excessive fattening, because these rats weren’t overeating.