Fasting and the Ketogenic Diet

The ketogenic diet has had a recent surge in popularity. This is due to high profile individuals in the “biohacking” realm and movie stars using the ketogenic diet to make weight for an upcoming role.  Similarly, the use of intermittent fasting has become just as popular.


Google Trends: Red-“ketogenic diet” Blue-“Intermittent Fasting”

Looking at the interest on Google, the search for ketogenic diets (blue) and intermittent fasting (red) have mimicked one another in appeal. While at first appearing different, at a molecular level these two approaches to diet are very similar. The ketogenic diet creates a cellular milieu similar to the fasted state with the added benefit of getting to eat. While the similarities of the two dietary approaches are striking to say the least, there are still differences between the two.

The “fasted state” occurs when no nutrients are taken into the body, blood glucose and insulin levels begin to fall, adrenaline and cortisol levels rise and the liver responds with the release of energy stores. The absence of nutrients is a signal to the body to mobilize reserves and to begin food-seeking behaviors (e.g. hunger and searching for sustenance). In the absence of food the body begins to prepare for the upcoming famine and therefore starts to begin the process of liberating fats from adipose tissue for use in the peripheral tissues. Our fat reserves are sufficient to allow us to survive for weeks without food with even the leanest individual capable of surviving a week without food under the right circumstances. This extended fasted state is where the magic happens. Without nutrient input, our body begins to undergo a process of recycling and repair that otherwise will not occur. Inside all our cells are broken bits of proteins, oxidized damaged cellular components and dysfunctional mitochondria. During starvation conditions the cell takes account of these precious resources and begins the process of autophagy (“self-eating” for those that didn’t learn Ancient Greek). This process of autophagy removes these damages components and repurposes them to new use as cellular building blocks or as an energy source. While energy is scarce, the normal immune cell production of white blood cells is diminished and cells associated with autoimmunity disappear. The lack of food intake also means that the blood levels of bacterial associated endotoxin drop, decreasing systemic inflammation. These effects can have lasting positive effects on our health, as reducing inflammation is a key component to living a long and pain free life.
The ketogenic diet can produce a lot of similar effects as fasting can. This comes from the reduction in insulin associated with carbohydrate and protein intake. The increase in fat intake also increases mitochondrial density, creating new mitochondria that are healthy and robust. The increase in fatty acid use also increases the amount of our free radical scavenging enzymes, reducing cellular damage. The increase in fat also provides building blocks for anti-inflammatory molecules produced by the body including the endocannabinoids, leukotrienes and prostaglandins. The ketogenic diet is also capable of regulating certain forms of dysbiosis caused by carbohydrate hungry yeast or bacteria.
When combined together, the ketogenic diet and fasting regimes are powerful therapeutics for the treatment of a host of disorders that stem from inflammation, dysbiosis or metabolic disease. This includes previously intractable diseases like Alzheimer’s, Parkinson’s, multiple sclerosis, cancer, ALS and more. The list of the maladies that these simple tools have been shown to be effective for continues to grow and more research will continue to expand the list for potential use.

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