This article provides a brief discussion on the subject of ketosis and related metabolic processes. To begin, let’s define some terms:
Ketone– an organic compound with a carbonyl group attached to two carbon atoms. This compound can be used in the Krebs cycle to produce energy. Here I’ll use the term to identify an alternate energy source to glucose.
Ketosis– a condition in which the body is producing ketones to fuel the body.
Ketoacidosis– when the body’s blood pH is too acidic because of excess ketones which can lead to coma or even death, if not treated.
Ketogenesis– the creation of ketones by the body due to a lack of glucose.
Ketogenic diet– a way of eating that induces ketogenisis, usually by reducing carbohydrate intake.
Ketosis is often confused with Ketoacidosis. The difference between these two terms is the quantity. Ketosis is a condition when you have a small amount of ketones floating around in your blood (0.5-3.0 mM) helping fuel your body. Ketoacidosis is when there are too many ketones (15-25 mM) causing your blood pH to get dangerously acidic. Low-carb diets are sometimes criticized for inducing ketosis for fear of ketoacidosis, and in turn harming your kidneys. WebMD says “Consuming too much protein puts a strain on the kidneys, which can make a person susceptible to kidney disease,”(1) when talking about ketosis. A low-carb diet doesn’t mean high protein. It is often the case, but it’s not necessary. You might wonder how the body regulates the amount of ketones. You might also be concerned that being in a state of ketosis would lead to ketoacidosis if a low-carb diet were continued for a long period of time.
The truth is that the body only goes into ketoacidosis (the harmful condition) if there’s a problem with insulin. When the body doesn’t produce insulin (type 1 diabetes or late stage type 2 diabetes), the cells keep asking for energy. When the body is not getting enough energy from glucose (since insulin is the key that allows glucose into the cell), it starts making ketones for energy. Since insulin also inhibits ketogenesis, a lack of insulin can result in ketoacidosis because there’s nothing to tell the body to stop making ketones. The system is broken which results in ketone abundance, but the ketones didn’t break the system.
A study in 2004 was conducted with 89 obese (BMI >35) individuals who were put on a ketogenic diet for 6 months (2). Eating a normal amount of protein and a high percentage of fat, they lost weight and improved their lab numbers. Their cholesterol numbers improved and “the level of blood glucose significantly decreased. The changes in the level of urea and creatinine were not statistically significant.“ This means there was no increase in acid in the blood and the kidneys did not seem to be in any kind of distress.
Ketosis can be induced by eating a low-carb diet. Whether it incorporates high fat or high protein low-carb doesn’t make much difference. Ketones will be created from fat and protein to fuel the body, and are actually up to 25% more efficient (3) in the heart muscle. When a healthy individual with the correct amount of insulin in his or her body consumes a low-carb diet, the insulin regulates ketone production, keeping ketoacidosis in check. If you are healthy and don’t have insulin issues, there’s no danger of ketoacidosis.
Have some questions? Post them below in the comments section.