Why We Get Fat: And What to Do About It (22 page)

In 1946, when the very first edition of Dr. Spock’s child-rearing bible,
Baby and Child Care
, was published, it counseled, “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.” And that sentence remained in every edition—five more, constituting in total some fifty million copies—for the next fifty years.

In 1963, when Sir Stanley Davidson and Reginald Passmore published
Human Nutrition and Dietetics
, considered the definitive source of dietary wisdom for a generation of British medical practitioners, they wrote, “All popular ‘slimming regimes’ involve a restriction in dietary carbohydrate,” and advised, “The intake of foods rich in carbohydrate should be drastically reduced since over-indulgence in such foods is the most common cause of obesity.” The same year, Passmore co-authored an article in the
British Journal of Nutrition
that began with this declaration: “Every woman knows that carbohydrate is fattening: this is a piece of common knowledge, which few nutritionists would dispute.”

•   •   •

By this time, physicians had taken to testing the effectiveness of diets that restricted carbohydrates, and they began reporting on these tests and their own clinical experience. (The first was in 1936 by Per Hanssen, a physician at Steno Memorial Hospital in Copenhagen.) The results were unambiguous: the diets seemed to induce significant weight loss without requiring that the patients go hungry.

The pioneering studies were done at the DuPont Company in Delaware in the late 1940s. “We had urged our overweight employees to cut down on the size of the portions they ate, to count their calories, to limit the amounts of fats and carbohydrates in their meals, to get more exercise,” explained George Gehrmann, head of the company’s industrial-medicine division. “None of those things had worked.” So Gehrmann had his colleague Alfred Pennington look into the problem, and Pennington prescribed a mostly meat diet to twenty overweight employees. They lost an average of two pounds a week, rarely eating fewer than twenty-four hundred calories a day and averaging three thousand calories, or twice that typically prescribed in the semi-starvation diets that we’re still being told to follow today. “Notable was a lack of hunger between meals,” Pennington wrote, “increased physical energy and sense of well being.” The DuPont subjects were allowed no more than eighty calories of carbohydrates per meal. “In a few cases,” Pennington reported, “even this much carbohydrate prevented weight loss, though an [unrestricted] intake of protein and fat, more exclusively, was successful.”

Pennington’s conclusions were then confirmed in the 1950s by Margaret Ohlson, head of the nutrition department at Michigan State University, and by her student Charlotte Young, working at Cornell University. When overweight students were put on conventional semi-starvation diets, Ohlson reported, they lost little weight and “reported a lack of ‘pep’ throughout … [and] they were discouraged because they were always conscious of being
hungry.” When they ate only a few hundred carbohydrate calories a day but plenty of protein and fat, they lost an average of three pounds per week and “reported a feeling of well-being and satisfaction. Hunger between meals was not a problem.”

The reports continued into the 1970s. Some physicians prescribed carbohydrate restriction with a limit to how much fat and protein could be eaten—allowing anywhere from six hundred total calories a day to twenty-one hundred—and some prescribed the diet as an “eat as much as you like diet,” which means as much meat, fowl, and fish as desired, as much protein and fat, but still very few carbohydrates. Some physicians allowed virtually no carbohydrates, not even green vegetables. Some allowed as much as four hundred calories’ worth. These studies were carried out at hospitals and universities in the United States, the United Kingdom, Canada, Cuba, France, Germany, Sweden, and Switzerland. The diets were prescribed for obese adults and children, for men and women, and the results were invariably the same. The dieters lost weight with little effort and felt little or no hunger while doing so.

By the mid-1960s, when physicians began holding regular conferences dedicated to obesity, the conferences invariably included a single talk on dietary therapy, and that talk invariably was on the unique effectiveness of carbohydrate-restricted diets.
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Five of these conferences were held in the United States and Europe between 1967 and 1974. The largest was at the National Institutes of Health in Bethesda, Maryland, in October 1973. The talk on dietary treatment was given by Charlotte Young of Cornell.

Young reviewed the hundred-year history of the fattening carbohydrate, including Pennington’s work at Dupont and Ohlson’s
at Michigan State. She talked about her own work, putting obese young men on diets of eighteen hundred calories. These diets all included the same amount of protein, but some had virtually no carbohydrates and a lot of fat; some had a few hundred calories of carbohydrates and not quite so much fat. “Weight loss, fat loss, and percent weight loss as fat appeared to be inversely related to the level of carbohydrate in the diets,” Young reported. In other words, the fewer carbohydrates these men ate and the more fat, the more weight they lost and the more body fat they lost—exactly what Adiposity 101 would have predicted. What’s more, all of these carbohydrate-restricted diets, Young said, “gave excellent clinical results as measured by freedom from hunger, allaying of excessive fatigue, satisfactory weight loss, suitability for long term weight reduction and subsequent weight control.”

Now, you might think that, given these results, confirmed in studies around the world, and given the science of fat metabolism—Adiposity 101—which had by then been worked out in detail, the medical community and the public health authorities might have had an epiphany. Perhaps they might have launched a campaign to convince individuals who gain weight easily that they should avoid, at the very least, the most fattening of carbohydrate-rich foods—the refined, easily digestible carbohydrates and sugars. But this obviously isn’t what happened.

By the 1960s, obesity had come to be perceived as an eating disorder, and so the actual science of fat regulation, as I said previously, wasn’t considered relevant (as it still isn’t). Adiposity 101 was discussed in the physiology, endocrinology, and biochemistry journals, but rarely crossed over into the medical journals or the literature on obesity itself. When it did, as in a lengthy article in
The Journal of the American Medical Association
in 1963, it was ignored. Few doctors were willing to accept a cure for obesity predicated on the notion that fat people can eat large portions of any food, let alone as much as they want. This simply ran contrary
to what had now come to be accepted as the obvious reason why fat people get fat to begin with, that they eat too much.

But there was another problem as well. Health officials had come to believe that dietary fat causes heart disease, and that carbohydrates are what these authorities would come to call “heart-healthy.” This is why the famous Food Guide Pyramid of the U.S. Department of Agriculture would later put fats and oils at the top, to be “used sparingly”; meat was near the top because meat (like fish and fowl to a lesser extent) has considerable fat in it—even lean meat—and fat-free carbohydrates—or fattening carbohydrates, as they used to be known—were at the bottom, the staples of a supposedly healthy diet.

This belief in the carbohydrate as “heart-healthy” started in the 1960s and it couldn’t be reconciled with the idea that carbohydrates make us fat. After all, if dietary fat causes heart attacks, then a diet that replaces carbohydrates with more fatty foods threatens to kill us, even if it slims us down in the process. As a result, doctors and nutritionists started attacking carbohydrate-restricted diets, because they bought into an idea about heart disease
that was barely even tested at the time and would fail to be confirmed once it was (as I will soon discuss). They believed it, though, because people they respected believed it, and those people believed it because, well, other people they respected believed it.

A particularly glaring example comes from
The New York Times
in 1965, the same year the American Physiological Society published an eight-hundred-page
Handbook of Physiology
dedicated to the science of fat metabolism, a subject I addressed in the previous chapter, and concluding, effectively, that “carbohydrate is driving insulin is driving fat.”

The
Times
article, “New Diet Decried by Nutritionists: Dangers Are Seen in Low Carbohydrate Intake,” quoted Harvard’s Jean Mayer as claiming that to prescribe carbohydrate-restricted diets to the public was “the equivalent of mass murder.”

Mass murder
.

Mayer’s logic? Well, first, as the
Times
explained, “It is a medical fact that no dieter can lose weight unless he cuts down on excess calories, either by taking in fewer of them, or by burning them up.” We now know that this is not a medical fact, but the nutritionists didn’t in 1965, and most of them still don’t. Second, because these diets restrict carbohydrates, they compensate by allowing more fat. It’s the high-fat nature of the diets, the
Times
explained, that prompted Mayer to make the mass murder accusation.

This is how such diets have been treated ever since. The belief that dietary fat causes heart disease—saturated fat, particularly—led directly to the idea that carbohydrates prevent it. By the early 1980s, Jane Brody of the
Times
, the single most influential journalist on the nutrition beat for the last forty years, was telling us “we need to eat more carbohydrates” and advocating starches and bread as diet foods. “Not only is eating pasta at the height of fashion,” she wrote, “it can help you lose weight.” In 1983, when British authorities compiled their “Proposals for Nutritional Guidelines for Health Education in Britain,” they had to explain
that “the previous nutritional advice in the UK to limit the intake of all carbohydrates as a means of weight control now runs counter to current thinking.”

This logic may have reached the pinnacle of absurdity in 1995 (at least I hope it did), when the American Heart Association published a pamphlet suggesting that we can eat virtually anything with impunity—even candy and sugar—as long as it’s low in fat: “To control the amount and kind of fat, saturated fatty acids and dietary cholesterol you eat,” the AHA counseled, “choose snacks from other food groups such as … low-fat cookies, low-fat crackers … unsalted pretzels, hard candy, gum drops, sugar, syrup, honey, jam, jelly, marmalade (as spreads).”

This advice and the shunning of low-carbohydrate weight-loss diets might make sense if dietary fat did indeed cause heart disease, as we’ve been hearing now for fifty years. But there has always been copious evidence suggesting that this obsession with dietary fat is misdirected—another case of the health authorities fooling first themselves, and then the rest of us, because they thought they knew the truth about a subject in advance of actually doing any meaningful research. In the next chapter, I’ll discuss what the history of our species has to say about whether a diet that prohibits
only
the fattening carbohydrates—starches, anything made from flour, sugars—is healthy or not, even if it means eating significant fat and meat instead. In the chapter that follows, I’ll discuss what the latest medical research says about the nature of a healthy diet.

In 1919, a New York cardiologist named Blake Donaldson began prescribing mostly meat diets to his obese and overweight patients—“fat cardiacs,” he called them, because even ninety years ago these men were obviously prime candidates for a heart attack. As Donaldson told it, he had visited the local Museum of Natural History and asked the resident anthropologists what our prehistoric ancestors ate, and they told him “the fattest meat they could kill,” with some minimal roots and berries for variety. So Donaldson decided that fatty meat should be “the essential part of any reducing diet,” and this is what he prescribed to his patients: half a pound three times a day, with a small portion of fruit or potato to substitute for the berries and roots. Donaldson continued with this prescription until he retired forty years later, successfully treating (or so he claimed) seventeen thousand patients for their weight problems.
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Donaldson may or may not have been ahead of his time, but the argument that we should eat what we evolved to eat has remained forceful ever since. The idea is that the longer a particular type of food has been part of the human diet, the more beneficial
and less harmful it probably is—the better adapted we become to that food. And if some food is new to human diets, or new in large quantities, it’s likely that we haven’t yet had time to adapt, and so it’s doing us harm.