Good Calories, Bad Calories (61 page)

In response to Thorpe’s testimonial, JAMA could no longer claim outright that a high-fat, carbohydrate-restricted diet would actual y increase weight, as it had asserted five years earlier, but it stil insisted in a 1958 editorial that the diet would endangered health, whatever else it might accomplish.*99

Pennington’s diet failed to fulfil the criterion of being “adequate in al essential nutrients,” JAMA wrote. Thus, “the most reasonable diet to employ for weight reduction is one that maintains normal proportions of fat, proteins, and carbohydrates and simply limits the total quantity of the mixture.” As it would do for the next fifty years, JAMA disregarded firsthand testimony from clinicians and trivialized the scientific issues; it promoted diets not because they were effective, but because they were supposedly “least harmful”—invariably basing its notion of harm on ideas that had been and would be strongly chal enged for decades.

Al the while, the DuPont experience would be confirmed in the literature repeatedly. The first confirmation came from two dietitians, Margaret Ohlson and Charlotte Young, who published their observations in the Journal of the American Dietetic Association in 1952. Ohlson was chair of the food and nutrition department at Michigan State University. Young had studied with Ohlson in the 1940s and then moved to Ithaca, New York, to become a nutritionist at Cornel . Young also worked with Cornel ’s Student Medical Clinic, and it was in this capacity, along with struggles to control her own weight (she was five ten and weighed 260 pounds), that she had become dissatisfied with calorie-restricted diets.

Ohlson began her research by testing Pennington’s diet on members of her own laboratory. “The edibility of the food mixture, the feeling of wel -being of the subjects and the ease with which meal pattern could be fitted into a daily schedule involving business and social engagements, suggested a further trial with patients,” Ohlson reported. She then prepared a version of Pennington’s diet that restricted both carbohydrates and calories, on the mistaken assumption that the diet must work by restricting calories. This was the diet that Young would also use at Cornel . It al owed only fourteen to fifteen hundred calories a day, out of which 24 percent was protein, 54 percent was fat, and 22 percent was carbohydrates.*100 Because the diet was also calorie-restricted, it did not actual y test Pennington’s observation that weight would be lost even without such a calorie limitation. Nor did Ohlson or Young address the question of why their subjects never reported feeling hungry even though it provided no more calories than a typical semi-starvation diet. Stil , their observations are relevant, particularly because they came in an era when high-fat diets were not yet widely considered deadly, so that researchers were not biased by this perception.

Ohlson initial y tested a twelve-hundred-calorie low-fat diet on four overweight young women. This was eight hundred to a thousand calories less than these women normal y ate to maintain their weight, Ohlson reported, so they should have lost at least twenty-two pounds each over the fifteen weeks of the trial. Rather, the four women lost zero, six, seven, and seventeen pounds. The “subjects reported lack of ‘pep’ throughout…[and] they were discouraged because they were always conscious of being hungry.”

Ohlson then tested her calorie-restricted version of Pennington’s diet on seven women who ranged from mildly overweight to obese. These women fol owed the diet for sixteen weeks and lost between nineteen and thirty-seven pounds. In a comparison of the low-fat diet of twelve hundred calories with the carbohydrate-restricted diet of fourteen to fifteen hundred calories, the former resulted in an average weight loss of a half-pound a week, whereas the latter diet, higher in calories, induced an average weight loss of almost three pounds weekly. “Without exception, the low-carbohydrate reducing diet resulted in satisfactory weight losses,” Ohlson wrote. “The subjects reported a feeling of wel -being and satisfaction. Hunger between meals was not a problem.”

Over a ten-year period, Ohlson’s laboratory tested a range of dietary compositions on nearly 150 women, including between 50 and 60 women on her version of Pennington’s diet. She also tested low-protein diets and diets low in fat (only 180 calories, or less than 15 percent fat) but high in carbohydrates. Her subjects considered these low-fat diets to be “dry, uninteresting, [and] hard to eat,” no more satisfying than those regimens of turnips, bread, and cabbage that Ancel Keys had fed his conscientious objectors. Diets with 360 calories of fat proved “sufficient to provide acceptability,” she added, but her subjects “uniformly” preferred the high-fat diets, with seven to eight hundred calories of fat. At that level, the women “did not appear to give as much thought to forbidden foods,” and “they also appeared to be more successful in control ing appetite during col ege vacations.” Simply put, Ohlson’s subjects were not as hungry on the high-fat, low-carbohydrate diet as they were on the low-fat, high-carbohydrate regimens.

On these high-fat, high-protein diets, according to Ohlson, her subjects appeared to add muscle or lean-tissue mass, rather than losing it, which she believed to happen inevitably with both balanced semi-starvation diets and low-protein diets. On Ohlson’s version of Pennington’s diet, her subjects stored nitrogen while losing one to three pounds of weight a week. This “can only mean that replenishment of the lean muscle mass is taking place,”

Ohlson said, an observation reinforced in some of her subjects by “a reduction in dress size [that] appeared to be greater than seemed reasonable on the basis of pounds lost.”

Meanwhile, Charlotte Young at Cornel first tested Ohlson’s version of Pennington’s diet on sixteen overweight women, who lost between nine and twenty-six pounds in ten weeks, averaging nearly two pounds per week. They were “unanimous in saying that they had not been hungry,” Young wrote. She reported that her subjects seemed unexpectedly healthy while on the diets, “despite an unusual y heavy siege of colds and ‘flu’ on the campus,” and that several “reported that their skins had never looked better than during the reducing regimen.” “No excessive fatigue was evident; there was a sense of wel -being unusual during weight reduction.” In 1957, Young published the results of a second trial with eight overweight male students, and the results were comparable. Young fed these men an eighteen-hundred-calorie version of Ohlson’s diet. After nine weeks, the men had lost between thirteen and twenty-eight pounds, averaging almost three pounds each week. Their weight loss, Young said, “in every case” actual y exceeded that expected purely from the reduction in calories. Ohlson’s and Young’s journal articles were ignored.

As with virtual y al weight-loss diet studies until the last decade, these were not the kind of randomized, wel -control ed trials necessary to establish whether a particular diet actual y extends life or prevents chronic disease. Subjects were not randomly selected to fol ow a low-carbohydrate diet, or a low-calorie diet, or no diet at al , and then fol owed for months or years to compare the treatments and their respective risks and benefits. Rather, the logic behind them was that obese patients were themselves the controls because they had tried calorie-restricted diets and they hadn’t been successful.

For an obese person, it’s a reasonable assumption that they have tried to weigh less by eating less—i.e., calorie restriction. If that approach had worked, as Hilde Bruch noted, that person would not be obese. When Bruch described a fifty-pound weight loss in a young patient eating Pennington’s diet, she also reported that the woman had described her life, as Bruch’s obese patients often did, as a constant, ongoing failure to control her appetite and restrict her calories to a level that would maintain or reduce her weight.

In 1961, Wil iam Leith of McGil University reported his clinical experience with forty-eight patients on Pennington’s diet al of whom had previously tried low-calorie diets “without measurable success.” Half had used appetite-suppressant drugs (“anorectic agents,” as Leith cal ed them), seven had taken

“bulk substitutes,” and “eight had participated in group psychotherapy for a period of eight months,” and yet “none of them showed a sustained loss of weight.” Twenty-eight, by contrast, lost a significant portion of their excess weight on Pennington’s diet—between ten and forty pounds, averaging one and a half pounds each week. “Our results do show that satisfactory weight loss may be accomplished by a ful caloric, low carbohydrate diet,” Leith concluded. “The patients ingested protein and fat as desired.” For the successful dieters, a significant success had fol owed a lifetime of failure.

Neither the individuals who wish to lose weight nor the clinicians who prescribe the diet need a randomized trial to tel them if it works. Such a trial is necessary only to establish that the diet works better than some other diet, and whether it leads to sustained benefits in health and longevity.

Until recently, few nutritionists or clinicians considered it worth their time and effort to test weight-reducing diets. Instead, they spent their careers studying the physiological and psychological abnormalities associated with the condition of obesity, comparing food consumption and physical activity in obese and lean individuals, and studying obesity in animals. They tried to induce fat people to endure semi-starvation by behavioral modification; they studied pharmacological methods of suppressing hunger, or surgical methods of reducing the amount of food that could be consumed or digested.*101 Testing diets or even treating obese patients was regarded as lesser work. “To be honest, obesity treatment is extremely boring,” said Per Björntorp, who was among the most prominent European authorities on obesity in the 1970s and 1980s. “It’s very difficult and unrewarding.” When obese individuals came to his biochemistry laboratory at the University of Göteborg, they were referred to the local nutritionists to be taught how to count and restrict calories. Since everyone knew that obesity was caused by overeating, why bother with diet trials? “There’s no point wasting your time on them,” George Bray, considered one of the world’s leading authorities, said in a recent interview. “If you get restriction of energy you wil lose weight, unequivocal y. It’s not an issue.”

When clinical investigators did test the efficacy of high-fat, carbohydrate-restricted diets, however, the results were remarkably consistent. Every investigator reported weight losses of between one and five pounds a week even when the investigators running the trial seemed more concerned with establishing that the diets caused deleterious side effects. Every investigator who discussed the subjective experiences of the test subjects reported that they suffered none of the symptoms of semi-starvation or food deprivation—“excessive fatigue, irritability, mental depression and extreme hunger,” as Margaret Ohlson described them.

The last of these symptoms may be the most tel ing. The diets induced significant weight loss without hunger even when the patients ate only a few hundred calories a day, as Russel Wilder’s did at the Mayo Clinic in the early 1930s, or 650–800 calories per day, as was the case with the patients treated by George Blackburn and Bruce Bistrian of MIT’s department of nutrition and food science and the Harvard Medical School in the 1970s. Wilder was treating his obese patients with the very low-calorie diet developed by Frank Evans, principal y meat, fish, and egg white, with 80–100 calories’ worth of green vegetables. “The absence of complaints of hunger has been remarkable,” Wilder wrote. Bistrian and Blackburn reported in 1985 that they had prescribed their diet of lean meat, fish, and fowl—almost 50 percent protein calories and 50 percent fat—to seven hundred patients. On average, the patients lost forty-seven pounds over a period of four months; nearly three pounds a week. “People loved it,” said Blackburn.†102

Significant weight loss without hunger was also reported when the diet was prescribed at 1,000 calories, as the University of Würzburg clinicians Heinrich Kasper and Udo Rabast did in a series of trials through the 1970s; at 1,200 calories, as the University of Iowa nutritionist Wil ard Krehl reported in 1967; at 1,320 calories, as Edgar Gordon of the University of Wisconsin reported in JAMA in 1963; at 1,400 or 1,800 calories, as Young and Ohlson did; at 2,200 calories, as the Swedish clinician Bertil Sjöval reported in 1957, and even when the diet provided more than 2,700 calories a day, as reported also in 1957 by Weldon Walker, who would later become chief of cardiology at the Walter Reed Army Medical Center in Washington. The same has invariably been the case even when patients are simply “encouraged to eat as much as [is] necessary to avoid feeling hungry,” but to avoid carbohydrates in doing so, as John LaRosa, now president of the State University of New York Downstate Medical Center, reported in 1980.

Every investigator who compared these carbohydrate-restricted diets with more balanced low-calorie diets also reported that the carbohydrate-restricted diet performed at least as wel , and usual y better, even when the caloric content of the carbohydrate-restricted diet was significantly greater

—say, 1,850 calories versus 950 calories, as Per Hanssen reported in 1936; or 2,200 calories versus 1,200 calories, as Bertil Sjöval reported in 1957; or even an “eat as much as you like” diet compared with a 1,000-calorie diet, as Trevor Silverstone of St. Bartholomew’s Hospital in London reported in 1963 in a study of obese diabetics. The same held true for children, too. In 1979, L. Peña and his col eagues from the Higher Institute of Medical Sciences in Havana reported that they had randomized 104 obese children to either an “eat as much as you like” high-fat, high-protein diet with only 80

calories of carbohydrates, or an 1,100-calorie diet of which half the calories came from carbohydrates. The children on the carbohydrate-restricted diet lost almost twice as much weight as those who were semi-starved on the balanced diet.

Between 1963 and 1973, Robert Kemp, a physician at Walton Hospital in Liverpool, published three articles reporting his clinical experience with a low-carbohydrate, unrestricted-calorie diet. Kemp reported that his obese patients craved carbohydrates and were invariably puzzled and frustrated by two aspects of their condition: “that other people can eat just the same diet and remain thin,” and “that they themselves in earlier life may wel have been thin on the same amount and type of food on which they subsequently became fat.” These observations led Kemp to formulate “a working hypothesis that the degree of tolerance for carbohydrate varies from patient to patient and indeed in the same patient at different periods of life.” He then translated this hypothesis into a carbohydrate-restricted, calorie-unrestricted diet. Doing so, he said, made it “possible for the first time in [his] experience to produce worth-while results in obesity treatment.”