The low-fat diet didn’t ‘fail.’ We did
Review the past results of The National Health and Nutrition Examination Survey (NHANES), and you’ll conclude that the Obesity Epidemic began sometime in the late 1980s. In the surveys covering the prior 25 years, the adult obesity rate (determined by a 30-plus body mass index, or BMI) held steady between 14.3 and 16.4 percent.
By the NHANES survey that began in 1988, however, 25.2 percent had a BMI of 30-plus, an increase of 56.7 percent. To say this rise was a minor surprise would be a major understatement.
That’s because we were in the midst demonizing dietary fat and consecrating carbohydrates. Eating less of the former and more of the latter was lauded as the way lose weight and the incidence of heart disease.
By the mid-1950s, research led by Ancel Keys linked the consumption of dietary fat to an increase in body fat and saturated fat to heart-related health problems. In 1961, the American Heart Association released the first nutritional guidelines of any kind restricting saturated fat and cholesterol.
But it wasn’t until a senate hearing convened by George McGovern in July of 1976 that the link became a true talking point with the public. By 1977, the first edition of The Dietary Goals for the United States was published.
The document suggested a low-fat diet as a way to improve health and reduce the incidence of cardiovascular disease and diabetes. Specifically, dietary fat was to amount to no more than 30 percent of one’s daily caloric intake, with saturated fat comprising no more than a third of that.
During the next 10 years, the food industry created countless fat-free products as a way to “help,” but the good deed stemmed from corporate greed. It allowed the industry to use a new, ridiculously cheap sugar that also sweetened profit margins and ultimately harmed health: high-fructose corn syrup.
The end result was, to borrow a quotation from Dariush Mozaffarian, MD, DrPH, and the editor-in-chief of Tufts Health & Nutrition Newsletter, “a proliferation of reduced-fat products with poor nutritional value, such as low-fat breakfast cereals rich in starch and sugar and low-fat versions of salty snacks, salad dressings, muffins, cookies, and other desserts.”
Mozaffarian’s words appear in the March issue of the aforementioned newsletter in an article titled “Why the Low-Fat Diet Failed.” The article is highly informative and well-written, but an important element of it bothers me immensely.
The low-fat diet did not fail.
Dieters failed to appropriately follow the diet.
As evidence, consider Eat More, Weigh Less, a 1993 New York Times number-one bestseller written by the man who just might be the staunchest supporter of low-fat, high-carb eating, Dr. Dean Ornish. Here’s the list of the foods he suggests you eat “whenever you feel hungry [and] until you feel full”: fruits, vegetables, grains, and beans and legumes. Besides the expected ban on foods that contain even moderate amounts of fat, Ornish not only advises to avoid sugar and all “simple-sugar derivatives,” but also warns that some “non-fat or very low-fat commercially available products ... are high in sugar, so avoid these when possible.”
During the fat-free craze, though, too many people indiscriminately ate fat-free foods that were loaded with sugar.
In a round-table discussion televised in 2004 on the PBS show Frontline titled “Did the Low-Fat Diet Make Us Fat?”, Ornish provided an example. “I even had a patient once who was starting to gain weight on a so-called low-fat diet, and I said, ‘What are you eating?’ They [sic] said, ‘Oh, I’m eating just one or two a day.’ I said, ‘One or two pieces of these Entenmann’s cakes?’ ‘No, one or two cakes at a sitting.’ They [sic] said, ‘Well, it’s low fat ... It can’t be bad for me.’”
But it was.
It was just as bad for the diet’s reputation because the unrestrained eating done in the name of it caused the adult obesity rate in the U.S. to continue to escalate. By the 2003-2004 NHANES study, it reached 38 percent and low-fat eating had fallen out of favor.
Since that time, many of the most popular diets — Atkins, South Beach, Paleo, and Keto — have strictly limited the consumption of carbohydrates and encouraged the ingestion of “good” fats. Even the more mainstream Mediterranean diet caps carb consumption at 40 percent.
But this change in philosophy hasn’t ended or even slowed the escalation of the obesity rate. The most recent NHANES survey has it at 39.8 percent.
While I have always stressed for you to actively experiment and personalize your diet, that does not mean to dismiss science. Research shows that fat and simple carbs are far more likely to become body fat than protein and complex carbs. So if you want to diet, following a low-fat diet for a start and then experimenting to personalize it should lead to success.
Unless you personalize your diet by eating two low-fat cakes a day.