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57348659 - smiling young woman having dinner with her friendsWhat is Ketosis?
by ACE Physical Therapy and Sports Medicine Institute

Tid Bits of Info.

  • Approximately 75% of all calories are from fats in a Keto diet.
  • Studies have recorded a 10-12 lb weight loss in 4 weeks utilizing a Keto diet.
  • Ketoacidosis is a medical emergency and can be fatal.
  • Glucose is the primary fuel source of the body.
  • Starvation increases ketosis but also causes the body to metabolize protein (muscle) at a higher than normal rate.

Ketosis is a normal metabolic process in the body that involves utilizing stored fat for energy instead of glucose. Normally, glucose provides fuel for the system, allowing your body to function normally. If glucose levels are low, the body will metabolize alternate sources of fuel to supply the proper amount of ATP for all bodily function. A diet containing very low carbohydrate levels can induce ketosis for weight loss. Research is still being done to determine the value and effects of ketosis on various health conditions.

The human body uses glucose as a primary fuel source. When the levels are inadequate to meet the body’s demands, it will begin to produce it through various metabolic processes.  Glucose usually comes from the diet and mainly carbohydrates.   Carbohydrates like fruits and dairy products or starchy foods such as pasta and bread can be broken down into sugars.  These carbohydrates can be utilized and “burned” as the primary fuel source providing the dietary intake is sufficient. In the event that there is an excess of glucose in the blood it can be stored in the form of glycogen in the muscles and liver.  These stores can be converted to glucose when needed in the future.

When the body’s glucose level is too low, the body goes into numerous processes to make more.  If the glucose supply cannot be restored to the necessary level, other fuel sources are utilized to produce ATP molecules.  One of these processes, to produce the needed ATP is Ketosis.  This process “breaks down” fat stores.  These stores are metabolized and the fatty acids are oxidized in the Krebs cycle which is a metabolic process that produces high levels of ATP molecules. This process requires oxygen and is linked to prolonged aerobic exercise that is best for “fat burning”.

Ketosis metabolizes fat stores and ketones are produced which in turn can be used to produce the energy source of the body.  If the ketone level rises too high, ketoacidosis can develop which can produce an acidic level that is detrimental to normal bodily functions and possibly cause death.

Weight Loss

Some people have attempted to utilize the process of ketosis to “burn” fat stores and lose weight.  If someone consumes low levels or no carbohydrates, the body will begin to use the alternative fuel sources to produce the energy molecules of ATP.  These diets are referred to as ketogenic or keto diets.   These diets are considered to be “high-fat diets” and can be used for short term weight loss.  The depletion of carbohydrates and glucose in the blood stream forces the body to transition to another metabolic process to produce the needed energy molecules.

75463197 - the celebrations with a barbecue

Heart Disease

Keto diets might help to control medical conditions such as cardiovascular disease by improving the HDL cholesterol (“good” cholesterol).  This might be related to the weight loss associated Keto diets or the consumption of healthier foods.  Most major healthcare groups and organizations that support heart health agree that there is not enough concrete scientific evidence to indicate that Keto diets provide sufficient health benefits to the heart.


Diabetic patients are recommended to adhere to a low carbohydrate diet because they are unable to process and use the glucose in their blood due to the lack of sufficient insulin.   If the diabetic patient is careless and does not monitor their ketone levels which rise with the use of a Keto diet they can develop the serious and potentially deadly condition ketoacidosis.

Ketosis is a metabolic process that is utilized in the body to develop energy producing molecules of ATP when the level of the primary fuel source, glucose, is not adequate.  Some people are proponents of using ketosis to lose weight by eating a low carbohydrate diet which lowers the glucose levels and enhances the “burning” of fat stores.  This has shown promise for short term weight loss but has not been proven to be effective for a prolonged time period.




3 Responses to WHAT IS KETOSIS?

  1. Shelby says:

    Heart disease and diabetes are two of the top leading medical diagnosis and causes of death in the US. It is important to understand how your diet and exercise can improve or hinder these processes. This article did a great job and breaking down the physiology behind energy “ATP” and also how our body uses certain food sources as in fats, carbs, proteins etc. It is important to find a balance in these components for a healthy lifestyle but more important if you are already diagnosed with a condition such as heart disease or diabetes. Their are many fad diets out there that patients will try or get on and not all of them work well. Patients need to consider many different areas when it comes to dieting, dieting alone cannot improve your overall health as you need to exercise, diet, and focus on your mental health to improve over all well being.

  2. Jeanne says:

    Good break down of a very complex process especially in light of some recent research I did to defend why having a standing option at work is so important! As a society many of us are very sedentary. Sitting means we don’t use postural muscles. Postural muscles make the enzyme (LPL) that allows fat to be used as energy in muscles. When postural muscles go unused for prolonged periods they change the activity level of the LPL enzyme that allow fat to be used as energy in the muscles. In ketosis the body is now using fat as the energy source. Since the LPL enzyme function is now reduced, fat cannot even be used as an energy source. If the fat isn’t gets re-stored as fat. The next energy source to be pilfered in the absence of carbohydrates and depleted glycogen would then become muscle. There is smooth muscle on organs, skeletal muscle and heart muscle. Using muscle like this causes wasting. The body works best when it is allowed to use what is best for it but of course in crisis it has the work around – ketosis. Ketone bodies production is driven by the body’s need for food. They are short fatty acids that are able to cross the blood brain barrier. This type of diet when carefully monitored has been shown to help control seizures in some types of epilepsy. If a person has been in ketosis then eating carbohydrates again without increased activity will produce significant weight gain since starting the starvation process reduced the metabolic needs. In addition it takes less energy for the body to use carbohydrates. This survival mechanism is great when food was sometimes scarce but is not a diet that should go unmonitored. Move throughout the day! The body is very efficient and we want it to stay that way. We need all our energy systems to be fully functioning.

  3. Carlin, SPT says:

    Like Jeanne said, this article took a very complex topic and broke it down in a way that is easily understandable. I liked that pros and cons of the low carb diet were given. Often when it comes diets, only the positive aspects are brought to light and the dangers/lack of evidence is ignored. Whenever it comes to trying a new diet, it is best to consult a nutritionist or dietitian to determine what should and should not be included.

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