Understanding Optimal Ketosis and Ketone Levels

The Ketogenic diet is increasing in popularity, with thousands more taking it up every day. If you’re reading this, I’m assuming that you already know a little about the Keto diet, or maybe you’re on a keto diet right now!

People who follow a ketogenic diet can achieve ketosis. But now everyone can have optimal ketosis, which is ideal for maximizing weight loss on a diet.

Most of the benefits you get from a ketogenic diet require a high ketone level and low glucose in the body. Keep on reading to learn more:


Ketosis occurs when the body has an extremely high fat-burning rate. Also, the brain indirectly runs on fat via ketone bodies. These are energy molecules in the blood (like blood sugar), which become fuel for our minds after being turned from fat by the liver.

To boost ketone production, the amount of insulin in your bloodstream must be low. The lower your insulin, the higher your ketone composition.

And when you have a well-controlled, adequately large amount of ketones in your blood, it’s proof that your insulin is deficient. Therefore, you’re enjoying the maximum effect of your low-carbohydrate diet.

Understanding Ketone Levels

When discussing ketone levels or ketosis levels, keto experts often refer to The Art and Science of Low Carbohydrate Living by Jeff Volek, Ph.D., RD, and Dr. Stephen Phinney, MD, Ph.D.

It recommends nutritional ketosis begins at molecular concentration levels of 0.5 mmol/L. That means that the minute you cross that 0.5 thresholds, you’re “in ketosis.”

From there, nutritional ketosis is regarded as “light” through 1.0 mmol/L (light is still good!), then becomes “optimal” 1.0 mmol/L through a 3.0 mmol/L range.

So, how do you identify what ketone level to aim for? It depends on your purposes.

Why Optimal Ketosis?

Take a look at these situations. Do any of these describe your situation?:

  • You’ve been following a Keto diet for a while, but your weight loss has been slow. Perhaps you’ve been experiencing low energy levels throughout.
  • You’ve had a good run losing weight, but now your Keto diet has stopped, you still have some more weight you want to drop.
  • You’ve just started a Keto diet. Either you’ve not seen any significant weight loss, or you have seen some, but it comes with an extended period of Keto flu, low energy levels, and mental clarity.
  • You’ve slipped in and out of the Keto diet and want to start again correctly and achieve some fast, steady fat burning.

Optimal ketosis is the state in which your body is most efficiently handling its supplies of fats for fuel. A lot of us are close, but not quite there.

Thus, many experience several keto side effects such as extended bouts of keto flu, occasional drops in energy levels, and weight loss plateaus.

When your body is using its fats efficiently while sticking to this method, you’ll find your self experiencing all the benefits of the keto diet:

Their hunger goes away, and cravings start to dissipate. They’re now able to focus at work all through the day, with no slumps of energy and tiredness. Any excess weight starts to fall away again if they recently been a bit lazy with their diet and have got back into an optimal ketosis state.

It’s a great feeling and something that you should try to explain to your non-keto friends. But some don’t seem to get that it’s possible not to get hungry every few hours or want a mid-afternoon, post lunchtime nap!

What Should Your Ketone Level Be?

If your purpose for living a ketogenic lifestyle is to lose weight, doing “light nutritional ketosis” or 0.5 mmol/L-1.0 mmol/L is a good starting point. From there, set your goal for “optimal ketosis,” which is when your ketone levels are between 1.0 mmol/L-3.0 mmol/L. 

People who want to practice the ketogenic diet to help with their medical conditions like epilepsy, cancer, or endocrine and metabolic disorders, are commonly directed to aim for much higher ketone levels. Your ketone levels should range between 3.0 mmol/L and 5.0 mmol/L.

People who are fasting or consume a much higher fat-to-protein rate will look to levels in the 3.0 mmol/L-8.0 mmol/L range. But you don’t need to go there. 

The optimal ketosis range is termed “optimal” for a reason, and it’s precisely where you’ll want to be for weight-loss and general health purposes if you practice moderation and get in the groove of eating a keto diet.

Ways to Measure Ketones

There are three natures of ketone bodies: Acetone, Acetoacetate, and Beta-Hydroxybutyrate (BHB). Unlike protein consumption, where your lean mass weight determines the daily amount, the number of carbs you can take can be estimated using the following:

Blood ketone meter

It’s the most reliable way to measure BHB ketone bodies. The level of BHB in your bloodstream will inform you how much you have in your fuel tank, but it will not count the metabolic usage of ketones. 

Usually, this occurs when you have started following the ketogenic diet and are not yet fully keto-adjusted. Blood ketone meters can accurately determine ketones’ level in your blood, but they don’t come cheap.

To give you an idea, the tool itself is about $40, and the test strips cost $5 each. But if you want to be tested daily, it will cost you $150 per month plus the meter’s cost.

On the other hand, if you are doing a controlled ketogenic diet and numbers are crucial to you, a blood ketone meter may be the best and only option you have.

Today, there are reasonably-priced gadgets accessible for measuring ketone levels at home. One needle prick of the finger, and in just a few seconds, you’ll determine your blood ketone level.

Blood ketones are best calculated on a fasted stomach in the morning (before breakfast, that is). Here are some pointers on how to read the result:

  • Under 0.5 mmol/L is not recognized as “ketosis.” At this level, you’re likely not in your fat-burning condition.
  • Within 0.5-3.0 mmol/L is nutritional ketosis. This is where you’ll experience the beneficial effects on weight and metabolic health. For most people, it won’t matter where on this scale you fall.
  • About 1.5 – 3 mmol/L is what’s called “optimal ketosis” for some. If you have hit a weight-loss stall without an apparent reason, one possible interference is to increase your ketone levels. Although there is no scientific backing for this intervention, few cases may see the benefit.
  • Values of over 3 mmol/L aren’t required. That is, they will obtain neither better nor worse results than being at the 0.5-3 level. Greater values can also sometimes mean that you’re not getting adequate food. For type 1 diabetics, it can be caused by a severe shortage of insulin.

Breath testing – “Breathalyzer”

According to Volek and Phinney, a non-invasive and affordable option is to measure breath acetone concentration.

Acetone is one of the ketone bodies that occurs from a breakdown of acetoacetate. The level of acetone will show the metabolic usage of ketones.

The Ketonix Acetone Breathalyzer is available and grants an easy and cheap way to test your breath ketones (acetone). Always remember that breath ketones do not always exactly correspond with blood ketones.

Plus, it can be affected by numerous factors such as alcohol consumption and water intake. 

Urine ketone strips

Ketostix, Uriscan, and other urine detection strips are not as reliable. They only measure the level of acetoacetate – excess ketone that is not utilized by the body and are discharged via urine.

Urine ketone strips can still be beneficial through the first phase of the ketogenic diet. More so, if you want to measure the level of carbohydrates to begin ketosis.

Some people use them to determine if they are sensitive to certain keto-friendly foods that can hurt their progress.

They are simple to use and reasonably cheap. You’ll spend about $10 for 50 strips. That’s $6 a month if you test yourself every day.

If the urine detection strips don’t work for you, use any of the other two methods.


Listening to your body’s signs is another way of detecting whether you are in ketosis. You may even sometimes smell of acetone when your body is in ketosis.

This could be determined in your breath, sweat, or urine. Few people refer to this as ketogenic “fruity” smelling breath or “keto breath.” You are more than likely in ketosis if you detect any of these signs.

Technical Ways to Measure Your Ketone Level

  • Usually, ketone concentrations are lower in the morning and higher in the evening. Whatever time you choose to measure ketone levels, make sure to keep it consistent. Also, do not measure your ketone levels right after training. Ketone levels tend to be lower while your glucose levels are higher, so you won’t get typical numbers.
  • Keep in mind there are regular fluctuations caused by changes in hormone levels.
  • Another feature that affects the level of ketones is the amount of fat in your diet. Some may show a greater concentration of ketones after a high-fat meal. Coconut oil includes MCTs that will help you raise ketones.
  • To quickly boost your fat intake on a ketogenic diet, try fat bombs – snacks with at least 80% fat content.
  • Ketone levels tend to be higher after a prolonged aerobic exercise as your body uses glycogen stores. Exercise may support you get into ketosis faster.
  • Ketogenic “fruity” breath is not attractive for most people. To avoid this, drink a lot of water, mint tea, and make sure you consume foods rich in electrolytes. Avoid too many chewing gums and mints, as it may take you out of ketosis; there may be hidden carbs affecting your blood sugar.
  • Increase your electrolyte intake, especially potassium. You are likely going to spend some sodium and potassium when shifting to the keto diet.
  • Finally, if you find it difficult to lose weight on a ketogenic diet, there may be other reasons than the level of ketone bodies.

How to Achieve Optimal Ketosis

Many who firmly believe they are eating a strict low-carb diet are shocked when they measure their blood ketones. They may be at about only 0.2 or 0.4. Why?

The deal here is to bypass all apparent sources of carbohydrates. Consider time-restricted eating and use fat as a lever for taste and indulgence.

Sometimes putting MCT oil in your coffee or tea can boost your ketone levels, which may or may not resolve your stall. It may not work as “magic” for everyone, but it may just do the trick for some.

More Ketones, More Fat Loss?

Most people think that to lose as much fat as possible; they need to restrict their carbs intake as much as they can.

Currently, it’s not clear what the full impact of such carbs restriction is. Some diet authors, including Atkins himself, promoted the idea that more ketones equal more weight loss.

The thought they gave was that ketones are calories made from the breakdown of fat in the liver.

Although some fat loss may seem like a result of a potential “metabolic advantage,” the most significant factor for fat loss is natural appetite control.

Sure, urinary ketone discharge indicates that calories are being lost, but the result is still insignificant.

Based on current studies, the number of calories lost in the urine as ketones are not notable (100 kcal at most). Anecdotally, greater levels of ketones may reduce fat loss.

Few people who sustain lower ketone levels (trace ketones) appear to lose fat more efficiently. Why does that happen? One answer is that high ketone levels in the bloodstream may slightly increase insulin and block the release of free fatty acids from fat cells.

Also, when becoming keto-adapted, some individuals endure relatively greater carbohydrate consumptions without disrupting ketosis. It’s up to you to find your optimal carbs consumption.

As disclosed above, high ketone levels won’t help you burn significantly more calories. As long as you stay in nutritional ketosis (0.5 to 3.0 mM), reasonable amounts of carbohydrates can be added to your diet.

Ketones and Exercise

Does exercise affect ketone levels? Yes, but the results differ from one person to the next.

Furthermore, anaerobic exercise, like weight training, sprinting, or jumping, will reduce circulating ketones. This can cause blood glucose to increase slightly and for ketones to temporarily go down.

With aerobic exercises, such as swimming, walking, jogging, and cycling, you’ll ordinarily notice an increase in circulating ketones. 

Does this mean you do not want to do anaerobic training while on a ketogenic diet? No, it doesn’t.

Observing your ketone levels will help you determine how your body responds to various foods and activities. And knowing how your body reacts will help you adjust your nutrition and food selections to maintain optimal ketone levels.

If it Doesn’t Work

Being in optimal ketosis for an extended period will guarantee that you will experience the maximal hormonal effect from eating a low-carb diet. If you don’t notice weight loss, you can be sure that too many carbs are likely not part of your weight issue and not hindering your weight loss.

A Word of Caution

No matter the goal, no one should aim for the orange or red zones; they’re almost impossible to obtain anyway and don’t increase the diet’s benefits.

The only people who should be worried about nearing them are type 1 diabetics. That’s because they are at risk of developing a diabetic complication called ketoacidosis. It is a serious condition that requires urgent medical attention. 

For them, the reward may not be worth the risk, which is why it is recommended that people with type 1 diabetes develop a diet plan with their care provider. 

Anyone trying the keto diet should examine the best approach with their medical provider. That’s because there can be risks connected with other pre-existing medical conditions. Some examples are kidney stones, hypercholesterolemia, or a family history of stroke or heart attack under 60 years old. 

Your level of ketosis is not suggested to be yet another thing in your life to stress over. Instead, consider it a mechanism to help you evaluate and adjust your eating habits as you follow your keto journey. 

Keep filtering your options as you go, and you’ll attain your optimal levels. Enjoy an exhilarating and healthful way of life, and even easily slide into those too-tight jeans you’ve been eyeing in the back of the closet.

Final Thoughts

The key to achieving optimal ketosis is to understand that many low-carb foods can still kick you out of ketosis if you consume too much in one sitting.

For optimal ketosis, you want to be limiting net carbs to 20g or preferably less per day.

At this level, every carb counts. So, if you’re aiming for optimal ketosis, it may be worth keeping a complete food journal for a few days to record your food intake.

You need to pay attention to all your meals’ elements, which means condiments, spices, seasonings, which can often be where carbs slip in.