How Does Ketosis Work?

What is Ketosis?  

To answer, “how does ketosis work?” you first have to understand what ketosis is; and yes, we wish this was taught in the classroom!

Sadly, as our current dietary recommendations are based on a high-carb low-fat diet, almost all people raised on this diet have never experienced ketosis and many don’t even know what it is; so, you’re not alone.

The good news is you’re here now and willing to learn, and we think what you will find in this article could become a life-changing moment for you.

In it’s most simple terms, ketosis is how your body does what it does. Or rather, it’s how your body should do what it does.

As noted above, many people eat a high-carb Standard American Diet and don’t get into ketosis. This is how they end up overweight, lethargic, and facing a diabetic diagnosis or heart disease.

Carbs themselves, are not the issue; it’s what they do inside our bodies in high quantities that matter over the long-run.

So, if you’ve heard that more people are doing a low-carb diet, what they’re really saying is they’re trying to push their body into ketosis.

Fast Facts on Ketosis:

• Ketosis is a side effect of not enough glucose in the body.
• Ketosis describes burning fat in the body and turning it into ketones.
• Many people eat a ketogenic diet to induce ketosis.
• Keto flu is the name given to the symptoms of low ketones.
• Ketosis is a normal metabolic state.

When your body is in ketosis, it’s burning fat and turning it into ketones, which can be used by your brain and body for energy.

Now that you understand, in simple terms, what ketosis is, it’s time to answer, “how does ketosis work?” and learn what you can do to make it happen faster.

We’ll also be sharing some more science further along as we go if you're interested in how to get into ketosis and what’s going on.

It sounds nerdy, but we love the science behind why ketosis works, and we’ll be sharing a major keto hack on why knowing this knowledge is enough to make you more accountable.

If you’ve struggled to stay on a ketogenic diet, it might be a sign you simply don’t know enough yet as to what's going on to get results. 

If you have any questions, be sure to join our Facebook Group for personalized advice.

Ketones in the Breath or Urine

The first place you might encounter ketones is on your breath or in your urine. This can be through keto breath (a foul odor that can sometimes occur during the transition) or from ketone testing.

Keto breath indicates ketosis is occurring, but that there aren’t enough ketones being made; if you are new to keto, keep going and it’ll usually resolve on its own in a few days or weeks.

You can also add in more carbs and go into ketosis slower to resolve the problem faster.

Ketone strips are very common for beginners. They are a cheap way to test for ketones, and for a brief while, they provide an effective way to know if you’re in ketosis or not.

To test for ketones in your urine, it’s important to test with your first urine sample of the day.

If the color of the test strip changes color, it indicates ketones are present. The more maroon the color turns, the more ketones are present.

While it varies by brand, your ketone testing strips should have a key for you to measure your color against. The darker the color, the more ketones are typically present.

However, this doesn’t necessarily indicate you are heavily in ketosis. All urine tests tell you is that ketones are being manufactured by your body and are present in your urine.

The goal of ketosis is not to pee ketones out, but to use them for brain and bodily fuel.

As you become fat-adapted, a process that takes around 4-5 weeks, your body will become more and more proficient at burning ketones for energy.

Therefore, over time, your urine strips will appear to become lighter and lighter if you are able to sustain ketosis.

In many cases, you might even worry you have been kicked out of ketosis at week 4-5, despite being committed to keto, because the color has faded completely.

Don’t panic. This often is a great sign that you are ready to put the urine strips down and focus instead on how you feel in ketosis.

After all, a urine strip can only tell you yes or no - it cannot tell you what is kicking you out of the state of ketosis or what you can do to accelerate it.

And, if you’re like us, you’ll want to know the answers to these all-important questions.

Signs you’re in ketosis include:

• More energy
• Fat loss
• Feeling amazing
• Less brain fog
• More focus
• Appetite suppression
• Need for less sleep
• Increased focus
• Short-term fatigue
• Insomnia

While not all of the symptoms of the first stage of ketosis are super awesome; no one wants to feel tired or lethargic, these are only temporary adjustments while you’re body learn to better use ketones.

We did a great article here that you can read to alleviate the symptoms of keto flu; which can be a clear sign you’re going into ketosis.

If you wish to advance to the next stage of testing, you do have more options.

This is sometimes when people move to test for ketones in the blood, which give an accurate portrayal of if you are in ketosis or not.

Ketones in the Blood

While usually not necessary, many people learning how does ketosis work enjoy testing their blood for ketones.

Unlike urine strips, which only tell you if ketones are eliminated, blood ketone meters can more accurately record the levels of ketones in your blood.

The exception to this rule is people with diabetes.

You will want to measure ketones alongside your regular glucose readings and work with your doctor to make sure your state of ketosis is working towards your overall goals.  

When your body metabolizes fat into ketones, the ketones are transported in the bloodstream to the brain and supporting vital organs for use as energy.

The blood is an accurate indicator of ketosis and is usually within a near-perfect accuracy of being in ketosis or not.    

And, unlike urine testing, using a blood ketone meter won’t expire after a few weeks or months of being in ketosis. It's an effective way to test long-term.

It’s also the only way you can test for ketoacidosis, a rare situation for diabetics who produce too many ketones.

Ketoacidosis is when you have over 20 mmol of ketones in your blood.

As the regular range will max out at around 6 mmol, with most people sustain 1.5 to 4 mmol per day, you can see this is a massive readjustment.

If you do not have diabetes, you really cannot even go over 6 mmol per day, even with fasting and extreme methods.

Your body is an efficient machine and will simply force you to eat or pass out.

We recommend neither of these and should point out that more ketones are not actually any better; you want to sustain nutritional ketosis, which is a moderate 1.5-3 mmol reading of ketones in your blood per day.

Benefits of testing ketones in the blood:

• Accurate readings
• Can warn diabetics of ketoacidosis
• Tells you if you’re in ketosis or not
• Proof your are in ketosis
• Confidence in your dietary choices

Some people may choose to test when going into ketosis to monitor the process. Once they are there, they put the test strips down.

You can also use them as needed to see if they have been kicked out - as a way to learn if how you feel is accurate. We recommend finding what works for you.  

The ADA recommends that ketone testing should be performed by people who are diabetic on sick days and whenever glucose is consistently high.

The ADA also states that blood ketone testing is preferred over urine ketone testing, but you should work with your doctor if you are diabetic to ensure you’re in a safe window.

The cons of testing ketones in the blood:

• Expensive
• Patents force you to stay with one brand
• Can make you miss the natural symptoms of ketosis
• Some people dislike the needles

Ultimately, we’ve found that most people can learn to read the symptoms of ketosis with time and patience. And that many people even say they prefer this method over time.

Not only is this method of testing free, but it’s a body-positive way to learn how to correct any micro-details a blood ketone meter may miss.

For example, bloating, lethargy, tiredness, and brain fog may all indicate you’ve been kicked out of ketosis.

But a meter will not tell you what foods you ate that did this, but you can learn to spot them for yourself.

For a more definitive guide on when and how to check to ketosis, here is our guide on how to test for ketosis.  

How Does Ketosis Work?

Now that you know how to test for ketosis, it’s time to step up.

Testing just scratches the surface. If you really want to know “how does ketosis work” you have to dig a little deeper.  

As mentioned, ketosis is a metabolic state, but what does this mean?

Your metabolism is the name given to the system that occurs in order for food to be turned into energy for bodily functions to happen.

In ketosis, you’re burning fat to turn it into ketones. 

This is very unique, as most diets rely on you eating a high-carb diet, which turns glucose into energy.

In ketosis, your metabolism changes. It’s this change that tells your body how fast you burn fat and is why so many people are loving the ketogenic diet.

When done right, the ketogenic diet is by far the most efficient way for your body to metabolize fat and feel more energized and aligned.

The ketogenic diet is a whole-body approach and boasts many lifestyle benefits, so even if you don’t want to lose weight, this is a great state of being to be in. Many great thinkers are using it for the brain benefits, to think more quickly and clearly.

Other people are using it to overcome “mommy brain,” and to beat their odds of Parkinsons and Alzheimer's disease. It might even surprise you to learn that the keto diet has been in clinical use for over 80 years (1).

Next up, we’re going to look at ketosis - or ketogenesis, in more detail.

What is Ketogenesis?

When people say ketosis, what they are really talking about is ketogenesis.

This is when ketone bodies are produced, mainly in the mitochondria of liver cells, and synthesis can occur in response to an unavailability of blood glucose, such as during fasting.

In simpler terms, the fewer carbs you eat the harder your body has to work to make a new fuel source to be able to carry out its regular bodily functions.

If you want the real science, here goes:

When the body has ample carbohydrates available as an energy source, glucose is oxidized to CO2; acetyl-CoA is formed as an intermediate in this process, first entering the citric acid cycle followed by complete conversion of its chemical energy to ATP in oxidative phosphorylation.

To get into ketosis, you do have to restrict your carbs for about 2-3 days.

This timeframe varies from person to person and depends on how much glycogen is in your liver.

When the body has excess carbohydrates available, some glucose is metabolized, and some of it is stored in the form of glycogen or, upon citrate excess, as fatty acids.

If you're coming from a low-carb diet, you’ll have less glycogen and can get into ketosis faster than someone who eats a high-carb diet.

We recommend lowering your carbs gradually for the best experience. If you reduce the carbs too quickly, you can experience keto flu, which micks the effects of the real flu.

As carbs retain up to three times as much water as fat, your body may become dehydrated.

Be sure to drink plenty of water and electrolytes, especially when transitioning to a keto diet.

Here are three easy ways to speed up ketogenesis:

1. Do a fast
2. Exercise more
3. Lower carbs

The body will make three types of ketones during ketogenesis.

Acetoacetate can be converted by the liver into β-hydroxybutyrate, or spontaneously turns into acetone, is the most common by far.

Acetone, which is generated through the decarboxylation of acetoacetate, either spontaneously or through the enzyme acetoacetate decarboxylase (2).

It can then be further metabolized either by CYP2E1 into hydroxyacetone (acetol) and then via propylene glycol to pyruvate, lactate, and acetate (usable for energy) and propionaldehyde, or via methylglyoxal to pyruvate and lactate (3).

When the body has no free carbs available, fat must be broken down into acetyl-CoA in order to get energy.

Acetyl-CoA is not being recycled through the citric acid cycle because the citric acid cycle intermediates (mainly oxaloacetate) have been depleted to feed the gluconeogenesis pathway, and the resulting accumulation of acetyl-CoA activates ketogenesis.

Around this time, your body may experience keto flu, but after 3-4 weeks of sustained ketosis you will become fat-adapted, and feel like a whole new person. 

We promise it’s totally worth it! But next, we also want to touch briefly on one key player in all of this ketosis talk. Insulin.

If you want to know who calls the shots, it’s this guy, right here.

The Importance of Insulin

We cannot discuss the ketogenic diet without addressing the importance of insulin. Insulin is an anabolic hormone that fundamentally regulates ketogenesis.

The goal of the ketogenic diet in very simple terms is to lower your insulin response.

When glucose is increased (due to consumption of carbs, for example), insulin secretion springs into action.

While sugar is usually made out to be the villain, it’s actually insulin that causes most of the problems. Insulin enables glucose to be stored as fat.

Insulin steps into the metabolic conversation and says, “It’s ok guys, sugar is here with me,” and leads it by the hand into your liver.

Once you hit your reserves, insulin then says, “Don’t worry, I have space over here.”

Too much insulin in your system can have catastrophic side-effects, namely, insulin resistance or pre-diabetes. If that sounds scary, it should be - insulin can be incredibly harmful.

Type 2 diabetes can often be managed using diet but your doctor may need to prescribe you with an expensive medication to combat the side-effects; so why not avoid all of the drama and put in the legwork now?

Symptoms of insulin resistance include:

• Extreme thirst or hunger
• Feeling hungry even after a meal
• Increased or frequent urination
• Tingling sensations in the hands or feet
• Feeling more tired than usual
• Frequent infections

If you have any of these symptoms, please contact your primary care doctor right away. You should request a blood draw, which can tell you if you're showing symptoms of pre-diabetes.

The good news is that with careful consideration and early intervention, the keto diet has been shown to be a powerful way to turn back the damage caused by insulin resistance and type 2 diabetes (4).

And, of course, it’s never too late to start on a path to a new you!

Getting into Ketosis Easily

We hope you understand better now and can confidently answer the question, how does ketosis work, and are feeling more confident as you prepare to venture forth.

By furthering your understanding of the keto diet, you will find it easier to stick to your new way of living, as you will understand the journey and what you have to gain.

You’ll also understand better what your body is doing and how it responds to different foods you feed it. This will optimize your results and make the rate of ketosis much stronger.

When all you can think about is fat loss, you’re missing a much bigger picture; how you feel and act and react to situations is largely determined by your metabolism.

Once you’re in ketosis, the rest will fall into place. You’ll feel how you were always meant to feel and be amazed at how simple and easy fat loss becomes.

If you’re someone who has struggled with weight loss, you will appreciate what a relief this will be to hear.

High-carb diets are an awful way to lose weight and just end up making you feel mad and hungry and tired all the time.

Instead, why not check out our five delicious keto smoothies to help kickstart your journey to the best version of you? They’re delicious and can help you get into ketosis within hours.

Resources

Gasior M, Rogawski MA, Hartman AL. Neuroprotective and disease-modifying effects of the ketogenic diet. Behav Pharmacol. 2006;17(5-6):431–439.

H Glew, Robert. (2010). You Can Get There From Here: Acetone, Anionic Ketones and Even-Carbon Fatty Acids can Provide Substrates for Gluconeogenesis.. Nigerian journal of physiological sciences : official publication of the Physiological Society of Nigeria. 25. 2-4.

Miller, O. N. and Bazzano, G. (1965), PROPANEDIOL METABOLISM AND ITS RELATION TO LACTIC ACID METABOLISM*. Annals of the New York Academy of Sciences, 119: 957-973. doi:10.1111/j.1749-6632.1965.tb47455.x

Yancy WS Jr, Foy M, Chalecki AM, Vernon MC, Westman EC. A low-carbohydrate, ketogenic diet to treat type 2 diabetes. Nutr Metab (Lond). 2005;2:34. Published 2005 Dec 1. doi:10.1186/1743-7075-2-34