From a young age we're taught that eating three meals a day, plus snacks, is healthy and necessary for the human body to function normally, and this rhetoric still dominates North American food guides today. Mark Mattson, the Current Chief of the Laboratory of Neuroscience at the National Institute on Aging, once asked:
Why is it that the normal diet is three meals a day plus snacks? . . . There are a lot of pressures to have that eating pattern, there's a lot of money involved. The food industry – are they going to make money from skipping breakfast like I did today? No, they're going to lose money. If people fast, the food industry loses money. What about the pharmaceutical industries? What if people do some intermittent fasting, exercise periodically and are very healthy? Is the pharmaceutical industry going to make any money on healthy people?
The quote above comes from a TED talk Mattson gave on the benefits of fasting, a practice which forces the body to switch its fuel source from glucose to ketones. Scientists are observing a wide variety of health benefits from this transition, from starving cancer to improving cognition, and a ketosis diet is now being implemented for people with cancer, Alzheimer's disease, epilepsy, and more. It has tremendous benefits for the brain, as explained by Mattson in his talk, but also for the body.
What Is Ketosis?
The human body only has two fuel sources, fat and glycogen (sugar). When we have a lot of sugar stored in the body (from consuming carbohydrates, for example, which turn into sugar), our body uses that sugar to feed our brain and other organs, providing the energy they need to function.
When the body runs out of glucose, it switches energy sources, from glycogen to fat. This can only happen when the body is depleted of its glycogen reserves.
We've been taught for years that the body needs glycogen to operate properly, but as we continue to expand our knowledge, it turns out this might not be the case.
When the body is done running on glycogen, and starts burning its fat reserves, it also produces what are called ketone bodies. These are molecules that are produced by the liver from fatty acids during periods of starvation, fasting, low food intake, carbohydrate restrictive/high fat diets, and long, intense exercise.
As it turns out, these ketone bodies have a wide range of health benefits.
Your Body Will Kill Cancer Cells
In 1923, scientist Otto Warburg hypothesized that cancer was caused by a metabolic process whereby cancer cells fuel their growth "by swallowing up enormous amounts of glucose (blood sugar) and breaking it down without oxygen." Coined the Warburg Effect, the theory was controversial at the time, but the past few decades have sparked new interest in it, and oncologists now use the dependence on glucose that cancer cells have to locate tumours within a patient's body.
Warburg made his discovery around the same time the ketogenic diet was found to be beneficial for epilepsy. Studies have shown that when the body produces ketones, they form a protective barrier around the brain, which is why more and more paediatricians are recommending the diet for children with epilepsy. It has a huge success rate, yet, since fasting is neither marketable nor profitable, receives little mainstream attention.