The ketogenic diet is a very popular, if somewhat controversial, diet. Going keto involves eating as little as 25-50 grams of carbs per day and consuming moderate amounts of protein and lots of healthy fats. Rice, bread, pasta, and potatoes are out, and meat, fish, eggs, nuts, olive oil, and non-starchy vegetables are in.
Cutting carbs from your diet will put you into a state called ketosis. Ketosis is where your body stops using glucose for fuel and instead runs on fat and ketones. This is very helpful for fat burning and weight loss, but a lot of people worry that being in ketosis is bad for your health.
The reality is that ketosis is an entirely natural state and one that ensures your body keeps on working when food is in short supply. If humans were not capable of ketosis, they would have died out during the first famine. Ketosis is literally a lifesaver.
However, there are several different types of ketosis, and some are more desirable than others, and a couple are actually best avoided.
In this article, we reveal the five main types of ketosis and explain how best to measure your ketone levels.
Different Types of Ketosis
There are several different types of ketosis. While all of them end up with your body using ketones for energy, the triggers for entering ketosis are different.
Fasted ketosis
Fasting means going without food for an extended period of time, usually 24 hours or more. Without food, your body has to use alternative sources of fuel, namely fat. Some of that fat is converted into ketones to provide your brain with an alternative to its preferred energy source, which is glucose.
Fasting is one of the fastest ways to get into ketosis. That’s why a lot of low-carb ketogenic diets also recommended periods of fasting.
Carb-restricted ketosis
Also known as nutritional ketosis, carb-restricted ketosis occurs when you reduce your carb intake to 25-50 grams per day.
With no dietary carbs to rely on for energy, and once all stores of glucose (glycogen) are depleted, your body will start to convert fat into ketones and use them for energy.
Depending on the size of your glycogen stores, getting into nutritional ketosis can take anywhere from several days to two weeks.
During this time, a lot of people experience side effects collectively known as the keto flu.
The symptoms of keto flu include headaches, cramps, dehydration, brain fog, fatigue, hunger, and cravings.
The keto flu soon passes once you enter true ketosis. Fasting and exercise can help speed up the descent into carb-restricted ketosis by depleting glycogen stores faster.
Supplemental ketosis
Some keto dieters take ketone supplements, namely beta-hydroxybutyrate or BHB ketone salts. Supplemental ketosis is not “real” ketosis, as the ketones come from an exogenous (external) source.
However, those ketones will show up in your urine and blood, giving the allusion of ketosis. Your body can also use these ketones for energy, and they make help speed up fat loss, reduce hunger, and alleviate some of the symptoms of keto flu.
Consuming medium-chained triglycerides (MCTS) can also lead to increased ketone production. MCTs are special fats that are not digested in the stomach but, instead, are ferried straight to your liver and converted to ketones for energy.
Sources of MCTs include coconut and palm oil. Ketogenic dieters often use MCTs to help them get into ketosis faster and for energy during their low-carb diets.
Alcoholic ketosis
While your body prefers to use protein, fat, and carbs for energy, if you drink alcohol, it can use that for energy too.
However, like fat, your brain cannot use alcohol for energy, so it’s converted into ketones. This is especially true when alcohol is consumed in excess and without food. Needless to say, alcoholic ketosis is not a healthy state to be in.
Pathological ketosis
Also known as ketone acidosis, pathological ketosis occurs in certain medical conditions, particularly diabetes.
It occurs when blood glucose levels are severally elevated. Diabetics are unable to digest glucose properly, and as such, their bodies may think that glucose levels are low even when blood glucose is very high and produce ketones in error.
Pathological ketosis is a serious risk to health and changes the acidity (Ph level) of the blood. Long-term ketoacidosis can cause liver failure, coma, and death. Alcoholic ketosis can also lead to ketoacidosis.
Are there different levels of ketosis?
A lot of people believe they are either in or out of ketosis, but that isn’t actually true.
There are always ketones in your blood; however, the levels can vary.
For example, during the night when you are sleeping, ketone levels increase as you won’t be eating.
Conversely, when you have breakfast, they’ll fall again.
Also, the lower your carb intake or the longer you fast, the higher your ketone levels will be.
You can check your level of ketosis by using keto sticks or a ketone blood monitor.
With keto sticks, you hold a paper or plastic strip in your stream of urine and then watch it change color. Most keto sticks are designed to turn purple when exposed to ketones, and the darker the color, the deeper your ketogenic state is.
However, while keto sticks are cheap and easy to use, they are not especially accurate. They really only tell you that there are ketones in your urine and not what your ketone levels are.
Ketone blood monitors analyze a pinprick of blood to provide a much more accurate ketone reading. Most also tell you ketone and blood glucose concentrations in parts per million. While they are much more accurate than keto sticks, blood monitors are expensive and invasive.
However, if you REALLY want to know your exact level of ketosis, using a ketone blood monitor is arguably the best way to do it.
Bottom Line
A lot of people think that the ketogenic diet is unhealthy or dangerous because they confuse ketosis with ketoacidosis.
The truth is that these are two very different states. While ketoacidosis is dangerous and needs to be avoided and treated, nutritional and fasted ketosis is entirely natural, and how your body produces energy when food or carbs are in short supply.
In fact, it would be safe to say that without the ability to burn ketones for fuel, humans would have died out many centuries ago when the first famines occurred.
Being in ketosis can actually be good for your health and is beneficial for weight loss, diabetics, speeding up recovery after brain injury, warding off Alzheimer’s and Parkinson’s diseases, and treating some cancers, epilepsy, and diabetes.
That said, some people should avoid ketosis as it could make existing medical conditions worse. People who should not enter ketosis include those with abdominal tumors, beta-oxidation defects, carnitine deficiencies, gallbladder disease, liver disease, kidney disease, pancreatitis, porphyria, and during pregnancy.
The ketogenic diet can definitely help you lose weight, but it’s not safe for everyone. If in doubt, speak to your doctor before cutting carbs from your diet and getting into ketosis.
