The ketogenic diet achieved national media exposure in the US in October 1994, when NBC's Dateline television programme reported the case of Charlie Abrahams, son of Hollywood producer Jim Abrahams. The two-year-old suffered from epilepsy that had remained uncontrolled by mainstream and alternative therapies. Abrahams discovered a reference to the ketogenic diet in an epilepsy guide for parents and brought Charlie to John M. Freeman at Johns Hopkins Hospital, which had continued to offer the therapy. Under the diet, Charlie's epilepsy was rapidly controlled and his developmental progress resumed. This inspired Abrahams to create the Charlie Foundation to promote the diet and fund research. A multicentre prospective study began in 1994, the results were presented to the American Epilepsy Society in 1996 and were published in 1998. There followed an explosion of scientific interest in the diet. In 1997, Abrahams produced a TV movie, ...First Do No Harm, starring Meryl Streep, in which a young boy's intractable epilepsy is successfully treated by the ketogenic diet.
The popular low-carb diets (such as Atkins or Paleo) modify a true keto diet. But they come with the same risks if you overdo it on fats and proteins and lay off the carbs. So why do people follow the diets? "They're everywhere, and people hear anecdotally that they work," McManus says. Theories about short-term low-carb diet success include lower appetite because fat burns slower than carbs. "But again, we don't know about the long term," she says. "And eating a restrictive diet, no matter what the plan, is difficult to sustain. Once you resume a normal diet, the weight will likely return."
First, that study, which was reported upon widely, was on mice. Mice are not like humans in the way they fatten or contract metabolic diseases. Journalists/media should stop reporting on mice stories as if they were applicable to humans, especially when there is such a large body of clinical trial data on humans. Let’s be clear: rigorous clinical trial data on humans trumps any data on mice. Every time. And what does the rigorous data on humans say?
The remaining calories in the keto diet come from protein — about 1 gram (g) per kilogram of body weight, so a 140-pound woman would need about 64 g of protein total. As for carbs: “Every body is different, but most people maintain ketosis with between 20 and 50 g of net carbs per day,” says Mattinson. Total carbohydrates minus fiber equals net carbs, she explains.
There are three essential components of all food: fats, carbohydrates and protein. The ketogenic diet is a carefully prescribed ratio of fats to carbohydrates and protein. This ratio causes the body to convert fat into substances called ketone bodies (thus the name). These ketones are then used for fuel in many cells of the body, including the brain. When this happens, the brain goes into a higher energy state and is better able to protect itself against seizures.
Here’s the real kicker: the reason why the Inuit don’t go into ketosis as readily as other ethnic groups is the high prevalence of a deleterious mutation in the CPT1A gene. This mutation permitted adaptation to a high fat, low carbohydrate diet in the sense that those carrying the gene could survive to reproductive age while eating a diet entirely at odds with our evolutionary history. However this gene is associated with high infant mortality rates due to hypoketotic hypoglycemia: when Inuit babies’ blood glucose levels drop, they are unable to utilize ketone bodies to sustain their brains. The very mutation that permits adult survival in extreme circumstances compromises infant health – a powerful example of the trade-offs inherent to evolution. Humans can indeed adapt to an extreme environment and an extreme diet, but that adaptation comes at a high cost.
The backbone of a keto plan is its extraordinarily high fat content, making up 65 to 80 percent of calories daily. Protein—which can raise blood glucose, though not as much as carbohydrate does—makes up 15 to 25 percent of calories on the keto diet. And carbs are even more heavily restricted to just 5 to 15 percent of calories. That’s only about 20 to 50 grams a day (compared with the average 245 grams daily), or the amount in a small apple or a cup of cooked brown rice, respectively.
The ketogenic diet is a high-fat, adequate-protein, low-carbohydrate diet that in medicine is used primarily to treat difficult-to-control (refractory) epilepsy in children. The diet forces the body to burn fats rather than carbohydrates. Normally, the carbohydrates contained in food are converted into glucose, which is then transported around the body and is particularly important in fueling brain function. However, if little carbohydrate remains in the diet, the liver converts fat into fatty acids and ketone bodies. The ketone bodies pass into the brain and replace glucose as an energy source. An elevated level of ketone bodies in the blood, a state known as ketosis, leads to a reduction in the frequency of epileptic seizures. Around half of children and young people with epilepsy who have tried some form of this diet saw the number of seizures drop by at least half, and the effect persists even after discontinuing the diet. Some evidence indicates that adults with epilepsy may benefit from the diet, and that a less strict regimen, such as a modified Atkins diet, is similarly effective. Potential side effects may include constipation, high cholesterol, growth slowing, acidosis, and kidney stones.
No animal on earth lives permanently in ketosis. Omnivorous animals such as bears and dogs, and obligate carnivores such as cats – the ultimate low-carbers – use gluconeogenesis to transform amino acids from protein into glucose. This allows them to maintain optimal blood glucose levels to fulfill their bodies’ needs for this vital nutrient. Only in prolonged starvation or a diabetic state will these animals enter ketosis.
A ketogenic diet could be an interesting alternative to treat certain conditions, and may accelerate weight loss. But it is hard to follow and it can be heavy on red meat and other fatty, processed, and salty foods that are notoriously unhealthy. We also do not know much about its long-term effects, probably because it’s so hard to stick with that people can’t eat this way for a long time. It is also important to remember that “yo-yo diets” that lead to rapid weight loss fluctuation are associated with increased mortality. Instead of engaging in the next popular diet that would last only a few weeks to months (for most people that includes a ketogenic diet), try to embrace change that is sustainable over the long term. A balanced, unprocessed diet, rich in very colorful fruits and vegetables, lean meats, fish, whole grains, nuts, seeds, olive oil, and lots of water seems to have the best evidence for a long, healthier, vibrant life.
The keto diet isn’t new, and it’s been around for nearly a century. It was originally developed to treat people with epilepsy. In the 1920s, researchers found that raised levels of ketones in the blood led to fewer epileptic seizures in patients. The keto diet is still used today to treat children with epilepsy who don’t respond well to anti-epileptic drugs.
Our human ancestors did not consume high-fat, low-carbohydrate diets and therefore would not have been in diet-induced ketosis. Even the most successful early hunters could not possibly have consumed enough fat to enter ketosis since african wildlife such as wildebeests, warthogs and impalas all have low body fat – well under 10%, and as low as 0.3% in the dry season.
Because people with type 2 diabetes are at an increased risk for cardiovascular disease, there’s a specific concern that the saturated fat in the diet may drive up LDL, or “bad,” cholesterol levels, and further increase the odds of heart problems. If you have type 2 diabetes, talk to your doctor before attempting a ketogenic diet. They may recommend a different weight-loss diet for you, like a reduced-calorie diet, to manage diabetes. Those with epilepsy should also consult their doctor before using this as part of their treatment plan.