Is Ketosis Bad?

Is Ketosis Bad?

In a nutshell, no. Ketosis is not intrinsically bad. Nature designed ketosis to help you survive long periods of food scarcity and even starvation. In other words, ketosis is a physiological adaptation, not a pathological state.

Yet you will often hear about the dangers of ketosis and ketogenic diets. There are two reasons why ketosis is sometimes linked to dangerous conditions: it is often confused with ketoacidosis, and it is different from the body's usual metabolic state of glycolysis. We discuss both below.

Is It True That Ketosis Is Bad?

Some people wonder why ketosis is bad or if it is bad.

Ketosis is an altered metabolic state of enhanced fat burning. When you are in ketosis, the body uses fat for fuel, converting it into acidic molecules called ketones. Not only does this enhanced fat burning provide a wide range of benefits (e.g. weight loss), but the ketones and ketosis themselves are scientifically proven to be great for your health.

However, many confuse ketosis with ketoacidosis, a potentially fatal condition where blood ketone levels become abnormally high and change the blood's pH. It's rare in healthy people but more common in those with type 1 diabetes. Ketosis, on the other hand, is when blood ketone levels increase within normal ranges to keep your brain, muscles, and heart functioning. Besides that, ketosis is not a medical condition put a normal process.

It is true that your body normally runs on sugar (glycolysis). It runs on ketones only when you fast or stop eating carbohydrates. That means that ketosis is something that happens only during an energy crisis. With that said, being in ketosis would be akin to being in a never-ending crisis, right?

Not really. In fact, the opposite may be true. People today would benefit from an occasional switch in their primary fuel. Research shows that this builds something called metabolic flexibility [1], the ability to switch from burning sugar to burning fat. Many people today are metabolically inflexible, and one reason why is overconsumption of high-glycemic foods, which leads to constant sugar burning [2].

Ketosis Effects on Organs


You already know that diet and metabolic health play a huge role in the health of different bodily systems. We'll explain how ketosis affects each organ to help you understand it's true effects better.


Animal studies show that ketosis increases antioxidant levels in this organ [3]. Studies also show that ketosis makes the liver burn more fat and use glucose more efficiently [4]. Ketosis may also help prevent non-alcoholic fatty liver disease (NAFLD), a condition affecting 25% of adults globally.

Because NAFLD is often the result of excess intake of refined carbohydrates, it makes sense that a diet that includes minimal intake of carbohydrates can help treat this condition. In fact, more and more studies are now looking into keto diets and ketosis as treatments for NAFLD [5].


Researchers have known for a long time that ketosis and ketogenic diets improve brain health and mental functioning [6]. Among many other things, ketosis enhances mental focus, improves mental clarity, boosts cognitive performance, improves brain energy levels, and balances mood.

Ketones are more efficient as brain fuel than glucose, producing more energy per unit of oxygen. This characteristic also helps protect the brain against oxidative stress (due to less oxygen needed) and also helps boost mitochondrial mass and number.


Besides the brain and muscles, your heart starts to use more ketones when glucose is running low. But not only that, the heart is completely reliant on ketones when severely damaged from a heart attack or during heart failure [7].

The heart requires an enormous amount of energy to keep pumping. Since ketones are such powerful fuels, it makes sense that your heart would be fully equipped to utilize them, especially during energy crises. And as far as your blood lipids are concerned, studies show that those improve on a keto diet in spite the higher fat intake [8].

Other Organs

There are many misconceptions surrounding ketosis and its effects on many other organs. For example, some people may believe that because ketones are acidic and released through urine they may disturb the pH of your urine, leading to kidney stone formation, but this is simply not true.

Some may also believe that muscles cannot function and grow on ketones and require glucose for that purpose. While this is true to some extent, being in ketosis does not deprive your muscles of glycogen.

Another common misconception is that ketosis leads to calcium leaching from the bones because it causes electrolyte imbalances [9]. But electrolyte imbalances happen before you are even in ketosis, during keto induction. These imbalances are also only short-lived, making them unlikely to cause bone loss.

Interested in learning more about ketosis? Make sure you check out our Keto Health Impacts Playlist on Youtube.  Also, check out these 5 biggest keto diet danger myths to learn more about what's true and what's not regarding ketosis and keto diets.

Positive Effect of Ketosis on Some Diseases

We've talked about what ketosis won't do to your body in regard to health outcomes. But you probably also want to know what it WILL do to your health and well-being. Here are some science-backed positive effects of ketosis on disease states.


Ketosis is proven to help control intractable epilepsy. One systematic review showed complete cessation of seizures in 16%, a 90% reduction in 32%, and greater than 50% reduction in 56% of the children involved in most studies [10].  


Ketosis helps people lose weight, reduce inflammation, and balance out blood glucose. All this, in turn, improves insulin sensitivity [11]. Ketosis and ketones especially improve insulin sensitivity in skeletal muscle according to some studies [12].  


Studies show that cancer cells require glucose to multiply, but can't do so with ketones [13]. That's why researchers are now looking into ketogenic diets as adjuvant cancer therapies.


Brains affected with Alzheimer's are less efficient in making energy from glucose. But ketones are a different story as studies show that Alzheimer’s brains can utilize to such an extent that they help slow down disease progression [14].


Obesity is not just a problem with excess weight, it is also characterized by slower metabolism and reduced mitochondrial activity. Ketosis helps speed up both while also burning fat along the way. That makes it a viable treatment for those struggling with excess weight.

However, this is only a short list of disorders that can be treated with ketosis and a keto diet. We will talk more about this topic in future articles. If you're interested and want to know when we publish a new article, make sure to join our mailing list to get notified.

Supplemental reading: The 5 Biggest Myths About Ketosis Dangers



Join Over 200,000 Fans

Sign up for the Kiss My Keto mailing list to get free keto resources, recipes, and strategies from the largest keto brand in the world.