Shining a Light on Sugar’s Dark History

Behind the ‘bad science’ that labeled fat, and not sugar, as food enemy number one.

The battle over American dietary guidelines has been raging for decades. One of the most controversial issues in nutrition? Fat and sugar. For the past 30 years, we’ve been instructed that a low-fat diet is the best way to lose weight or maintain a healthy lifestyle. In 1955, US President Dwight Eisenhower suffered a heart attack, and worked with his chief physician to encourage Americans to cut down on fat and cholesterol, stating that this would be the best way to avoid future heart disease. The first official government dietary guidelines were published in 1980, and they too advised Americans to limit fat. And though this diet surged in popularity (remember the low-fat craze in the '80s and '90s?), many are convinced it’s actually the exact opposite of how we should be eating, and that sugar is the biggest problem when it comes to weight gain and health problems. A recent article in The Guardian by writer Ian Leslie explores this controversy, looking at the reason why fat, and not sugar, became dietary enemy number one.  The article begins by introducing two important figures: Robert Lustig and John Yudkin. Lustig is something of a celebrity; his 90-minute talk titled Sugar: The Bitter Truth, has been viewed more than six million times on YouTube and argues that fructose is the culprit behind a majority of American health problems. And while Lustig originally believed his idea to be revolutionary, he soon came to find that a British professor back in 1972 had developed the exact same theory. The man was Yudkin, and he too brought the dangers of sugar to forefront, in a book called, Pure, White, and Deadly. But unfortunately, Yudkin's findings were not taken seriously, and he was eventually forced out of the nutrition industry. Now there’s some pretty clear evidence that sugar (a carbohydrate) is, in fact, not so great, and that fats and dietary cholesterol aren’t the bad guys we thought they were. The most recent trials have supported Yudkin’s theory. In a 2014 trial funded by the National Institutes of Health, 150 participants were prescribed a diet that controlled either their intake of carbs or fats.  The Guardian analyzes this study:

By the end of the year, the people on the low carbohydrate, high fat diet had lost about 8lbs more on average than the low-fat group. They were also more likely to lose weight from fat tissue; the low-fat group lost some weight too, but it came from the muscles.

Lustig had this idea back in 1972, and now we're learning that fat and cholesterol are actually OK, or at least not as uniformly bad as they were made out to be. So how did everything get so twisted? According to Leslie's article in The Guardian, it all happened sort of suddenly. At first, Lustig’s opinions were taken seriously, but he was soon met with competition that drastically contradicted his ideas. Keep in mind that Lustig was a professor, and a kind and quiet one at that. He was not prepared for the politics of the dietary guidelines, or able to charismatically justify his findings. Remember how President Eisenhower provided the American public with instructions to cut back on sugar? He got this advice from Dr. Paul Dudley White, who cited the research of a nutritionist at the University of Minnesota, known as Ancel Keys. Keys believed that the answer to the now rapidly-increasing heart disease was to cut out saturated fats, including red meat, butter, eggs, and cheese. His reasoning was that such food lead to an increase of cholesterol, which then congeals within the arteries and eventually staunches the blood flow. The end result would lead to heart problems.  Unlike Yudkin, Keys was bold and talkative, traits that garnered him with the support of government officials. The Guardian examines the possibility for Keys’s popularity:

Ancel Keys was intensely aware that Yudkin’s sugar hypothesis posed an alternative to his own. If Yudkin published a paper, Keys would excoriate it, and him. He called Yudkin’s theory 'a mountain of nonsense', and accused him of issuing 'propaganda' for the meat and dairy industries. 'Yudkin and his commercial backers are not deterred by the facts,' he said. 'They continue to sing the same discredited tune.' Yudkin never responded in kind.

Keys continued to provide evidence (though many consider it to have been manipulated) that contrasted Yudkin’s findings. And even though Yudkin’s discoveries were incredibly backed-up, his reputation was destroyed, and the high-fat, low-carb diet he defended was poo-pooed. Scientists, doctors, and government officials took the side of Keys, and food manufacturers complied. Thus, the low-fat fad was born.  Since then, there have been many controlled trials that have failed to illustrate that folks lose weight on low-fat or low-calorie diets on a long-term basis. Obesity rates have risen, even though the average American caloric intake has only increased by a sixth Many modern advocates of a healthy, high-fat and low-carb diet back up their theories based on the relationship between refined carbohydrates and insulin, the hormone responsible for regulating blood sugar. Refined carbohydrates tend to increase our insulin levels, and fat tissues send a signal to absorb energy from the blood. When the insulin is high for too long, we feel hungry and fatigued. So instead of working out, we eat. The cycle of weight gain continues.  Since then, many journalists and advocates have come out and argued against the low-fat, high-carb diet. But contradicting the norm has proven to be difficult; the majority of these advocates (perhaps most noteworthy, Nina Teicholz) have been met with criticism.  Perhaps some of the confusion coming from the modern day “sugar war” is due to the overwhelming number of opinions that are out there. With the proliferation of social media, we witness a great deal of contrasting ideas regarding our health, which makes it difficult for the average American to feel confident in his or her eating choices. It's hard to cut through the noise and discern the truth.  After all, at the end of the day most of us want to feel happy and healthy in our bodies. We tune into dietary advice because we want to make good choices. And if we can’t trust the instructions of our scientists, doctors, and politicians, that’s going to be a hard thing to do. For more of the story of Yudkin and Keys and the science of sugar, check out the full story in The Guardianamanda-kohr Amanda Kohr is a 25-year-old writer and photographer with a penchant for yoga, food, and travel. She prefers to bathe in the moonlight rather than the sun, and enjoys living in a state of the three C’s: cozy, creative, and curious. When she’s not writing, you can find her driving her VW Bug, looking for the next roadside attraction or family diner. She also roams the internet at amandakohr.com.