Let me introduce myself. My name is Mark Sisson. I’m 63 years young. I live and work in Malibu, California. In a past life I was a professional marathoner and triathlete. Now my life goal is to help 100 million people get healthy. I started this blog in 2006 to empower people to take full responsibility for their own health and enjoyment of life by investigating, discussing, and critically rethinking everything we’ve assumed to be true about health and wellness...Tell Me More
A little appreciated (but important) fact: for most of human history, a regular person would be regularly exposed to ketosis.
This was mostly light and transient, sometimes more protracted. But they were never far from a mildly ketogenic state for many reasons. Food availability wasn’t always a sure thing, after all.
Metabolic flexibility was honed with longer fasts as well as shorter stretches induced by compressed eating windows that came of a day away from camp or extended hours before morning meals.
Even in recent decades, people relied more on set mealtimes with little to no snacking in between, meaning more chances for ketosis. Being fat-adapted as a result conferred benefits beyond the immediate flexibility in energy sourcing. The evidence is present in research today….
Although keto is not a classical weight loss diet, it can and does help people lose body fat. After all, to generate ketones without eating ketogenic precursors, you have to liberate stored body fat.
But that’s not the main mechanism for ketogenic fat loss. Ketosis doesn’t melt body fat away like products touted on late night infomercials promise. Instead, it works for many of the same reasons a standard low-carb Primal way of eating works: by reducing insulin, increasing mobilization of stored body fat, and decreasing appetite.
This is the very real “magic” of metabolism.
Ketosis suppressing appetite may be the most important feature. The overriding drive to eat more food is the biggest impediment to weight loss, and it’s the reason why most diets fail. When people attempt to eat less food despite wanting more, they butt up against their own physiology. Few win that battle.
Ketogenic dieting avoids this issue altogether, suppressing the increase in hunger hormones that normally occurs after weight loss.
Ketogenic diets are especially effective for massive weight loss. If you have a ton of weight to lose, aiming for ketosis could help you lose body fat. Again, not because of any inherent fat-burning quality of the ketones, but because in order to make ketones you must liberate stored body fat.
Many diets work in the short-term and fail in the long run. Weight loss isn’t worth anything if you can’t keep it off. Ketogenic diets appear to be good for long-term maintenance of weight loss, at least compared to low-fat diets.
The ketogenic diet first emerged as a tool for clinicians to treat their patients with epilepsy. It was—and remains—the only thing with the consistent ability to prevent seizures. Whether it’s Thai kids with intractable epilepsy, Scandinavian kids with therapy-resistant epilepsy, or adults with refractory epilepsy, ketogenic diets just work.
Ketosis improves epilepsy via several mechanisms.
- It increases conversion of glutamate into glutamine into GABA, reducing neuronal excitability.
- It increases antioxidant status in the neuronal mitochondria, improving their function.
- It reduces free radical formation in neurons, a likely cause of seizures.
These effects on neuronal function and health, along with the ability of aging or degenerating brains to accept and utilize ketone bodies, also have implications for other brain conditions, like Parkinson’s, Alzheimer’s, bipolar disorder, and many psychiatric disorders.
Ketogenic diets aren’t just beneficial for brain disorders, however.
A Spanish ketogenic diet (keto with wine, basically) cured people of the metabolic syndrome and improved health markers of non-alcoholic fatty liver disease. Over 92% of subjects improved their liver health; 21% resolved it entirely.
In cancer patients, a keto diet preserves lean mass and causes fat loss.
Many researchers are exploring the use of ketogenic diets in preventing and treating cancer, although results are very preliminary.
Since ketosis can help with major brain disorders, many have wondered whether it can improve cognitive function in otherwise healthy people. Unfortunately, researchers haven’t studied the nootropic effects of ketogenic diets in healthy people—yet. They have looked at people with “milder” cognitive deficits, though, finding some promising effects.
- In mild cognitive decline, a ketogenic diet improves memory.
- In type 1 diabetics who experience reduced cognitive function when their blood sugar is low, increasing ketone production via medium chain triglycerides (found in coconut oil) restores it.
- In adults with bad memory, adding ketones improves cognition. The higher the serum ketones, the better the scores.
- In older adults, a very low-carb diet improves memory. Again, higher ketones predicts bigger improvements.
There’s reason to believe ketone-induced mitochondrial biogenesis in the brain will improve its function. Ketosis upregulates mitochondrial biogenesis in the brain. It literally creates new power plants in the brain that are good at burning fat-derived fuel.
This upregulation is actually responsible for the anticonvulsant benefits in patients with epilepsy, and, likely, the benefits seen in other brain disorders with glucose uptake problems. By providing an alternate source of brain power, brains that don’t run so well on glucose can begin burning fat. There’s no indication that ketosis only induces mitochondrial biogenesis in “unhealthy” brains. It simply hasn’t been studied yet, but I don’t see why it wouldn’t also build mitochondria in healthy brains.
For one, extra energy sources are always nice to have. That they might improve the way your brain works makes intuitive sense.
Two, exercise, perhaps our most reliable and potent booster of mitochondrial biogenesis in the brain, is downright nootropic. Exercise increases blood flow to the brain, which provides more oxygen and energy but also reduces free radical damage and enhances memory. It stimulates the creation of new neurons and the production of brain-derived neurotrophic factor (BDNF), a chemical that is instrumental in neuron preservation and formation. Exercise also promotes gene expression that supports plasticity, the brain’s crucial power to alter neural pathways.
If exercise promotes mitochondrial biogenesis and better functioning in the brain, perhaps ketosis does, too.
Anecdotes abound of people with intact cognitive function going on ketogenic diets and experiencing huge benefits to their mental performance. I’ve been experimenting with more protracted ketosis for some time now, and I can add my hat to the pile.
Foggy brain—we’ve all had it. Everything is muffled. Your synapses fire blanks, your neuronal communication medium is cold molasses. Works suffers, nothing gets done.
According to a very interesting post from Dr. Bill Lagakos of the always interesting Calories Proper blog, ketosis has the potential to alleviate brain fog. There’s a lot of biochemistry thrown around, so geeks are advised to read the post in full, but two big, relevant takeaways are these:
Elevated ammonia levels and depressed GABA levels contribute to brain fog. Ketosis increases brain glutamine synthetase, and brain glutamine synthetase mops up extra ammonia.
Ketosis increases GABA signaling. GABA is the “chill-out” neurotransmitter. It opposes glutamate, the excitatory neurotransmitter. We need both for cognitive function (or else we wouldn’t make both), but too much glutamate can lead to neuronal injury and neurodegeneration. GABA is the counterbalance.
Being keto-adapted likewise has several advantages for anyone interested in physical performance.
For one, it increases energy efficiency.
At any given intensity, a keto-adapted athlete burns more fat and less glycogen than a sugar-burning athlete. Long-term elite keto athletes can burn up to 2.3 times more fat at peak oxidation and 59% more fat overall than non-keto athletes, and they do it at higher intensities. They remain in the predominantly fat-burning zone at 70% of VO2max, whereas non-keto athletes switch over from predominantly fat burning to a spike in sugar-burning at 54.9% VO2max.
It also spares glycogen. Glycogen is high-octane fuel for intense efforts. We store it in the muscles and liver, but only about 2400 calories-worth—enough for a couple hours of intense activity at most. Once it’s gone, we have to carb up to replenish it.
Keto-adaptation allows us to do more work using fat and ketones for fuel, thereby saving glycogen for when we really need it. Since even the leanest among us carry tens of thousands of calories of body fat, our energy stores become virtually limitless on a ketogenic diet.
It builds mitochondria. Mitochondria are the power plants of our cells, transforming incoming nutrients into ATP. The more mitochondria we have, the more energy we can utilize and extract from the food we eat—and the more performance we can wring out of our bodies. Ketosis places new demands on our mitochondria, who adapt to the new energy environment by increasing in number.