5 Key Facts (And a Few Myths) About Low Carbohydrate Nutrition: Ketones

Ketones at levels typically seen during low carbohydrate eating are a signal of fat burning


When carbohydrate intake goes low enough (typically 50 grams a day or less), the body’s physiology shifts from a predominantly glucose (sugar)-burning metabolism to more of a fat-burning metabolism. This is what you want to happen when you are trying to lose weight! Lowering carbohydrate intake allows your body to reduce the production of insulin. Or if you have diabetes and take insulin shots, lowering carbohydrate intake allows you to lower your insulin shot doses. This is important because insulin is a potent stimulator of fat storage (lipogenesis) and a potent inhibitor of fat burning (lipolysis). In other words, lowering carbohydrate intake leads to lower insulin levels, which leads to more fat burning.


Fatty Acids and Ketones In The Body


When fat is burned, it is broken down into fatty acids and ketones. Both of these substances can be used by our body as sources of energy. In fact, they are an ingenious back-up source of energy for our body when carbohydrate is scarce, except carbohydrate is rarely scarce for most of us. Ketones are critical to our survival when the body is using these forms of energy because, like glucose, ketones can provide energy to the brain whereas fatty acids cannot.


Ketoacidosis and Diabetes


Ketones have one unhealthy connotation, however. In patients with type 1 diabetes who become ill and do not receive enough insulin medication, ketones can build up to very high levels, causing life-threatening ketoacidosis. Fortunately, this is very unlikely to occur in people whose pancreas still makes insulin. In fact, in one my earliest research studies, I measured the acid and ketone levels in the blood of patients who were following a very low carbohydrate nutritional approach, and none of the blood samples were acidotic. Ketone levels were elevated, demonstrating that fat-burning was occurring, but the levels were not nearly as high as would be seen in diabetic ketoacidosis.

As I mentioned in the previous entry, people with diabetes should check with their doctor before they lower their carbohydrate intake substantially because certain diabetes medications can cause blood glucose to go too low—these medications will need to be reduced or stopped. Also, patients with diabetes who take medicines called SGLT2 inhibitors (canagliflozin, dapagliflozin, and empagliflozin) may be at risk for ketoacidosis even if their blood glucose is controlled, so I recommend stopping these types of medication before reducing carbohydrate intake substantially.


How can you know if you are burning fat?


As I have outlined, ketones are a marker of fat-burning during low-carbohydrate nutrition. As such, some low carbohydrate nutrition followers like to measure their ketone levels to ensure they are lowering carbohydrate intake adequately. This can be done by urine strips, breath testing, or even special finger stick strips similar to those used for measuring glucose levels in diabetes. While it is not critical to measure your ketones to be successful with a low-carbohydrate way of eating (weight loss is also a good marker!), it helps to understand the changes in your metabolism that are occurring. Metabolizing your fat into ketones can be one of several safe and effective ways to lose weight and improve your health.

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Comments (5)

  1. willsblog

    In my experience in working with Diabetes patients, ketoacidosis is serious and requires hospitalization and stabilization. Diabetes is on the rise in America mainly because we eat far too many foods that are converted to sugars. There is a mentality in America that one should NEVER be “hungry” and should consume mass quantities of food until they are no longer “hungry”. The result is that America as a society is overweight, obese, sugar dependent and suffering from Diabetes. People as a whole do not know when to walk away from the table. This is especially true in restaurants that seem to cater to gluttony and large portions. Anytime I go to a restaurant I am amazed at the portion sizes and have had waiters and waitresses tell me that they have had people irate that the portions weren’t larger still. Another causation of Diabetes is the consumption of sugary drinks like Soda. If people would do a little research they would soon learn that ONE Soda contains MORE sugar than most people consume in a week yet, many consume Soda one or more times per day and then wonder why the weight piles on and Diabetes sets in. Since our bodies are 80 – 90% water, that is what we should be drinking the most of yet, many continue to consume Soda.

    October 17, 2016
  2. Munkyman

    If you lead a sedentary life, low carb is a great way to drop weight quick & then bringing your carbs up to reasonable levels with lots of vegetables & some fruit. The issue with most of us is the source of our carbs & the simplicity of them. We need to eat mostly complex carbs found in veggies avoiding the wheat & corn based carbs that come from the simpler sugars these produce. Most of our breads are terrible offenders when it comes to bad carbs… some find calling them bread at all offensive to what bread should be. I can’t help loving good hot French bread with a hefty dollop of field or grill butter… I just don’t eat it as often or in the quantities I’d like. Simple carbs have their place, but the simpler the carb the more important that it be the very best carb you can get. I use sugar because it’s cheaper & I don’t have diabetes, not even prediabetic, which surprised the hell out of me considering the amount of Mtn. Dew I used to consume daily. I prefer honey, it’s not reasonable for many things as it’s hard to keep suspended, it tends to crystallize & it’s expensive… it is however the finest of the simple carbs & for those watching your carbs a glass of tea with honey is far better for you & a lot less stress on your liver than a diet coke/pepsi.

    October 17, 2016
    1. Munkyman

      When you just have to have that Coke or Pepsi, get the one with real sugar & enjoy it, just make it a rare treat. The sugar substitutes used in diet soda generally impact the liver & pancreas as significantly as alcohol, no calories lots of chemistry.

      October 17, 2016
  3. bartholomew

    If anyone from thesis writers services is facing from low carbohydrate nutrition then he must note down all these key facts. This kind of articles can be very helpful for us to know how to improve our health and fitness on daily basis. In last paragraph we will know how to lose fats from our body because fats are not much good for us.

    February 14, 2017