Ketosis is a physiological state when your body burns substances called ketone bodies for fuel instead of glucose. It was considered an abnormality for a long time until the popularity of the Atkins diet brought it back into the public dialogue.
Ketone bodies are molecules broken down from fatty acids that your body uses when its glucose stores have run dry. For most people ketosis is a rare event because the majority of people get lots of calories from quickly digested carbohydrates and are in a perpetual “glucose burning” state.
The form of ketosis people are most familiar with is “ketoacidosis”, which is a traumatic condition that type 1 diabetics and alcoholics suffer from when they can’t make enough insulin to clear the sugar out of their system. Your body begins to produce excess amounts of glucagon which causes your liver to produce ketone bodies from fatty acids. If it goes unchecked blood pH levels will drop and your body’s in serious trouble.
Not All Ketosis Is Bad
The ketosis that arises from diabetics that are incapable of producing insulin (ketoacidosis) and the ketosis that comes from consistently low blood-sugar and insulin levels (nutritional ketosis) shouldn’t be blended together.
The former is a lethal condition that effects people with a severe regulatory disorder and the former is a sign of healthy metabolism that promotes a healthy body weight and sustained fat loss.
If you want a great overview of the benefits of ketosis then watch the video below.
It goes into a lot of nerdy detail, but this is a gem for anyone who wants to understand the mechanics of how your body uses energy and why it’s absolutely critically important for every aspect of your health.
If you watch the above video and follow 3/4 of it you’ll know more nutrition than a freshly minted medical school graduate.
Why Ketosis is Beneficial
Consider the following facts about ketosis and ketone bodies:
- Ketone bodies are the preferential sources of energy for your heart and muscle tissue (your heart improves its efficiency by 28% when it can consume ketones alongside glucose)
- A person with a lean body mass has about a 100,000 calorie reservoir of fat to turn into ketones, compared to a 1600 calorie reservoir of glucose.
- Ketosis is very well preserved in the animal kingdom, and most primates regularly undergo seasonal ketosis, including apes. (This is how animals hibernate).
- Ketone bodies produce more ATP per atom of Carbon than glucose, making it a more efficient source of energy.
- Ketones can mimic insulin within the body, but without the additional complications insulin has on energy storage. (Insulin makes you want to store fat, whereas the release of ketones causes you to burn fat).
Ketosis Is Pretty Common, Just Not for the Last 100 Years
People have the perception that ketosis is a rare event that only occurs during starvation or extreme illness. That’s not true. Your body undergoes mild ketosis every time you have a good nights rest. It’s the cause of morning breath, because ketone production causes your body to release acetone as a byproduct, which is why your mouth tastes yeast-y and sweet in the morning.
It’s actually a sign of a healthy metabolism.
Ketosis is a regular occurrence for our closely related ancestors in the animal kingdom. In 1997 researchers from the Harvard department of Anthropology went out to study the diet of 558 orangutans over the course of a year. Their primary motive was to discover how they eat.
It turns out their diet and caloric intake are very seasonal. During fruiting season they’d gorge on all the sugar they could get their hands on and gain weight since they ate about 8,500 calories a day. Presumably their insulin levels are very high. For the other half of the year they eat bark and have their calorie levels cut in half. It was during this time they’d lose all their weight, but they’d maintain good health despite energy intake that borders on starvation. The reason they can do it is because their bodies enter a prolonged state of ketosis, which allows them to tap into their fat stores without degrading their muscle.
Here are some interesting graphs of someone who starved himself for 30 days.
After 3 days or so his insulin and blood sugar levels tanked, and then stabilized:
During the same time his production of ketone bodies increased to about 5-7 mmol/L throughout his fast:
If you read personal recollections of people who have had to go many days without food they’ll tell a similar story. After about 2-3 days your energy levels get very low and you begin to get cranky and irritable. This is when your glucose stores run out and your body isn’t quite sure where it’s supposed to get its energy from.
Then all of a sudden they’ll start to feel better again and begin to get a second wind. That’s ketosis.
It seems incredible that the human body can go 40 days without eating food, but the reason it’s true is that your body has enough calories stored in its fat to last a loooong time. Ketosis shuts turns off the insulin/glucose spigot and allows your body to eat into its fat.
It’s also what prevents your body from cannibalizing itself. Your body can turn muscle into sugar but not all that efficiently. If you had to rely on muscle breakdown exclusively to feed yourself you’d last about 6-7 days before your organs failed.
Note: I’m not telling you to starve yourself. Far from it. Consider the above graphs a way to illustrate a point about how your body conserves energy. Nothing more, nothing less.
Ketosis is Probably Useful for Treating Many Diseases
The shift from burning glucose to burning ketones is one of the most important physiological shifts your body makes. It changes the way your body stores energy, the redox state of your mitochondria, and the availability of lots of enzymes that carry nutrients into and out of your cells.
It’s the way your body naturally wants to shed weight.
It’s one of the most important but least talked about concepts in health. It ticks me off that idiotic sophistry like alkalization gets peddled to the masses but absolutely critical concepts like ketosis are mostly swept under the rug.
It’s actually not the same thing as low carb, and you don’t have to be in it all the time, but it’s important to understand that periodic episodes of ketone burning is really important for being a healthier you.
A Few Closing Notes About What You Should Eat
Getting the benefits from ketosis can be best accomplished with the following steps:
- Limit the amount of sugar and cheap carbs as much as possible. Spikes in blood sugar and insulin jolt your body out of the ketosis state
- Get a good nights rest. Your body undergoes a mini fast every time you go to bed.
- High intensity exercise mimics many of the same benefits as prolonged nutritional ketosis.
Pan, Julie, et. al. “Human Brain ?-Hydroxybutyrate and Lactate Increase in Fasting-Induced Ketosis”
Yudkoff, Marc, et. al. “Brain amino acid metabolism and ketosis”
Paoli, A. “Beyond weight loss: a review of the therapeutic uses of very-low-carbohydrate (ketogenic) diets.”
Cunnane, Stephen, et. al. “Survival of the fattest: fat babies were the key to evolution of the
large human brain”
Knott, Cheryl. “Changes in Orangutan Caloric Intake, Energy Balance, and Ketones in Response to Fluctuating Fruit Availability”
Veech, Richard, et. al. “The therapeutic implications of ketone bodies: the effects of ketone bodies in pathological conditions: ketosis, ketogenic diet, redox states, insulin resistance, and mitochondrial metabolism”