If you’ve followed eating trends in recent years, you’ve likely heard of the ketogenic diet. This high-fat, low-carb method of eating has captivated popular culture, and more people than ever are wondering whether it will make a difference for their health. For the next four weeks, we’re going to distill the facts about the ketogenic diet into a series of articles so that you can come away with a better understanding of what this diet promises and whether it makes sense for you.
For this first article, we’re going to look at the history of this often-misunderstood diet and track its rise in popularity today. You might be surprised to learn that the intentionally entering ketosis isn’t new, but instead owes its inspiration to groundbreaking epilepsy research completed almost a century ago.
The Basics of Ketosis
At a basic level, the ketogenic diet is rooted in the idea that limiting your carbohydrate intake and consuming fats instead will put your body in a “fasted state” where it will burn ketones instead of glucose- resulting in better health for you.
The central idea is that following a meal plan that’s 60-75% fat, 15-30% protein, and 5-10% carbs puts the body in a state called ketosis. While your system primarily chooses to run on glucose (sugar), restricting your carbohydrate intake will cause it to feel that it’s starving, so it will generate a secondary energy source from fat to continue sending glucose to the brain. When you limit your carb supply, your body starts to break down fat into compounds called ketones, which are an alternative fuel source that many people believe has impressive benefits for your health and weight.
A History of Epilepsy Research
While the term ‘ketogenic’ wasn’t used until the 20th century, there’s a historical precedent for fasting for health. Ancient Greek physicians advocated for restricting one’s diet to treat diseases like epilepsy and other health problems, and fasting was considered to be integral to a healthy lifestyle. In fact, fasting is the only epilepsy treatment recorded by Hippocrates, and it was standard practice across much of the world for over two thousand years.
While most people today start the ketogenic diet to lose weight or otherwise improve their health, the eating strategy originated as a treatment for epilepsy. The research story begins with the first modern study of fasting and its role in epilepsy, which took place in France around 1911. The study found that epilepsy patients who consumed low-calorie diets combined with periods of fasting experienced fewer seizures and had fewer adverse health effects from the condition.
Around the same time, an American osteopathic physician named Hugh Conklin began to recommend fasting to his epileptic patients to help them get their seizures under control. Using a method that caused epileptic patients to fast for 18-25 days at a time, he boasted a 50 percent success rate for adults, and as high as 90 percent for children.
The Ketogenic Diet: A Compromise from Fasting
At first glance, these results were impressive. However, there was one glaring problem. While researchers had proof that fasting could control seizures, the obvious complication was that fasts are meant to be temporary. Many patients found that their seizures came back once they returned to their regular diet.
As other doctors began working to replicate these results, some experimented with modified fasts that focused on eliminating starches and sugars, rather than restricting all calories equally. Specifically, Dr. Wilder at the Mayo Clinic observed that certain epilepsy patients had fewer seizures when their blood sugar was lowered from eating a high-fat, low-carb diet. He consequently created the ketogenic diet as a way to mimic the metabolism that fasting produces.
The “Classic Keto” Approach
The premise behind going keto was simple: patients could be kept in a fasted state indefinitely if they limited their carbohydrate intake so that their bodies burned fat instead of glucose. Shifting the dietary ratio in favor of fat removed sugar from the bloodstream and triggered the body to consume an acid known as ketone bodies instead. In other words, successfully following the diet convinced the body to act metabolically as if it was starving, even as the individual took in enough calories and nutrition to remain comfortable.
Another Mayo Clinic physician named Dr. Peterman gets credit for standardizing the diet into the “classic keto” approach that is still followed today. In this traditional approach, experts advocate for a 4:1 ratio of fat to protein and carbs, with 90 percent of calories coming from fat, six percent from protein, and just four percent from carbs. Though these ratios are still considered the gold standard, a 3:1 ratio was also regarded as beneficial.
Historically acceptable foods for the ketogenic diet included the following:
- Non-starchy vegetables: leafy greens, cabbage, broccoli, cauliflower, peppers and onions
- Full Fat Dairy: yogurt, milk, and cheese products
- Protein: beef, pork, fish, poultry, soybeans, eggs and shellfish
- Nuts and Seeds: walnuts, pistachios, sunflower and pumpkin seeds, and almonds
- Fats: both animal and plant-based
- Fruits (in moderation): berries, avocado, rhubarb and coconut
In initial iterations of the ketogenic diet, doctors emphasized the importance of precise measurements for accurate results, meaning that food was often weighed down to the gram before consumption to keep participants on the right track.
The result? A diet as effective as fasting for treating epilepsy that could be maintained for far longer. Now in its second century, the basics of the eating strategy remain relatively unchanged. Nutritionists suggested that participants consume one gram of protein per kilogram of body weight, 10-15 daily grams of carbohydrates, and fill up the remainder of their diet with fat.
Dietary Fat Delivers Results
How exactly does the ketogenic diet work? Scientists still aren’t sure. The primary theory is that the natural structure of ketones causes them to have an anti-electrical effect on the brain. Abnormal electric impulses trigger seizures, so getting these under control prevents seizures from occurring.
Soon after the diet first gained popularity for treating epilepsy, doctors started noticing benefits of ketosis that went beyond seizure control. Children treated with the diet were observed as being less irritable, more alert, and easier to discipline. These children also slept better at night and seemingly had more energy. (Further research in the early 2000s validated these claims).
Despite the proven success of the ketogenic diet for treating epilepsy, the eating strategy was pushed into the sidelines as anticonvulsant drugs were developed and became mainstream in the following decades. As the diet became less popular, fewer dieticians were trained in its use. This led many people to implement it incorrectly, consequently leading to bad results and spreading the rumor that it wasn’t effective. In a matter of decades, the ketogenic diet was reduced to a footnote of history.
Returning to Mainstream Attention
By the 1990s, the ketogenic diet was all but forgotten, and those who studied it relegated it to the realm of historical curiosity, rather than medical fact.
So what changed? The tv show Dateline deserves much of the credit for reintroducing Americans to the ketogenic diet. An October 1994 episode reported on the case of Charlie, a two-year-old with severe epilepsy whose seizures were out of control until he started the keto diet. When Charlie sought treatment at John Hopkins, fewer than ten children were being administered the ketogenic diet each year.
Viewers watched how the ketogenic diet diminished Charlie’s seizures, and the show triggered an explosion of scientific interest in it. The eating strategy attracted so much attention that the child’s father directed the film “First Do No Harm” in 1997 about their experience with the diet, which starred Meryl Streep and aired on national TV.
Going Beyond Epilepsy: The Modern Era of the Ketogenic Diet
After the resurgence of interest in following the ketogenic diet, it was soon offered in hospitals as a viable option for treating epileptic patients. Today the ketogenic diet is available at almost all major children’s hospitals, and it continues to attract scientific interest for its role in neurological disorders.
However, the story of the ketogenic diet doesn’t end with epilepsy. If the eating plan’s only advantage was that it treated a relatively rare medical condition, far fewer people would be interested in it today. Instead, most people today are interested in the diet for it’s potential to help them lose weight. It’s not entirely clear when the keto diet first attracted attention as a weight loss solution, but the early and late nineties were dominated by the Atkins diet, and eating plan with a similar perspective of carbs. This renewed interest in the diet’s effects caused researchers to take a closer look at what it could offer otherwise healthy individuals, and the findings are impressive.
Today, most people who consider following the ketogenic diet do so for health reasons that go far beyond reducing seizures. What are they, and does the evidence live up to the hype? That’s a topic we plan to cover in a future article, so stay tuned!