What are the Ideal Ketone Levels For Ketosis?

The ketogenic diet was originally created and used as a treatment for those with epilepsy, and was first introduced in the 1920s for those who did respond to traditional anti-epileptic drugs. 

Because the ketogenic diet causes the body to run on fat as its primary fuel source instead of glucose (a state called ketosis), it’s been used successfully as a way to reduce or completely eliminate seizures by lowering excitability in the brain.

However, over the years, keto has become a popular diet for weight loss as well as for individuals with diabetes. Mainstream media along with the fitness industry often promote this diet as a way to accelerate weight loss, especially for people with poor blood glucose levels.

To determine if you’ve achieved ketosis, you’ll want to monitor your ketone levels and keep them in an optimal state. In this post, we’ll cover what the ideal ketone levels are and how to optimize them to meet your health goals. 

What are Ketones?

On a basic level, ketones (or ketone bodies) are the indicators that show whether you’re in ketosis or not, and are produced by your liver as your body enters the ketosis state.  

On a standard diet including all macronutrient groups, carbohydrates are broken down into glucose after you eat and are used for energy in the body. However, when you reduce your carbohydrate consumption on the keto diet, your body re-routes its energy production methods. 

Instead of using glucose to make ATP (the energy molecule), your body breaks down fats into fatty acids. These fatty acids undergo a process called beta oxidation in which they are then converted into a molecule called acetyl CoA. 

From here, two additional things happen: this molecule is used to produce ketone bodies and it is also used to produce ATP. That’s why ketones are almost always used as an indicator of whether an individual is in ketosis or not. 

What Level of Ketones Indicates Ketosis?

Nutritional ketosis, or restricting carbohydrate intake to achieve ketosis, is marked by a certain level of ketones in the blood. 

Research suggests that the standard level of ketones that indicate that a person has achieved ketosis is a hallmark value of 0.5-3 mmol/L blood ketones. 

It is important to note that ketone levels can fluctuate throughout the day. If you’ve noticed this or are worried about this as you begin your keto journey, bring it up with your nutritionist or dietitian. 

What are Ideal Ketone Levels?

The ideal ketone level may vary depending on your goals. Whereas nutritional ketosis is a normal physiological response to low carbohydrate intake, another state known as ketoacidosis is dangerous and can result in a coma or death. 

According to the Global Diabetes Community, nutritional ketosis is achieved when ketone levels hit 0.5. Light nutritional ketosis is said to be achieved when ketone levels are between 0.5 to 1.5 mmol/L, and the ideal ketone levels for weight loss are between 1.5 to 3 mmol/L. 

One study found these values to be helpful for seizure control as well. The authors found that 82 percent of those who had their ketone levels between 1.6 to 3 mmol/L remained seizure free, suggesting these values can provide the greatest health benefits.

Ketoacidosis

It’s important to note that nutritional ketosis is very different from the ketoacidosis seen in type 1 diabetes. Ketoacidosis typically shows up with high levels of ketones in the blood whereas in nutritional ketosis there are relatively lower levels of ketones in the blood. 

This is important to recognize, since many individuals focus on increasing their ketone levels to achieve nutritional ketosis. While the keto diet can help individuals with diabetes better control their blood sugar levels, having too high of ketones in the blood is not ideal and can lead to other complications. 

Ways to Reach Optimal Ketone Levels 

Now that we understand the difference between nutritional ketosis and ketoacidosis, what ketones are, and why they are a key indicator of the state of ketosis, here are some tips to help you to get those ideal ketone levels. 

There are a variety of approaches you can take, from nutrition to lifestyle hacks, that can help you reach ketosis.  If you’ve already started your ketogenic diet and have tried the common methods, you may benefit more from talking to a nutritionist about tweaking and optimizing your current approach. 

Here are some of the most common (and effective) strategies to help you get to optimal ketone levels. 

Restrict Your Carb Intake

The ketogenic diet is characterized by a very low carbohydrate intake. Ranges can vary, but in general, experts recommend that 70 to 80 percent of the calories you consume come from fats (no restrictions on what type of fat), 10 to 20 percent from protein, and five to 10 percent come from carbohydrates. 

In general, this means you can eat about 20 to 50 grams of carbs a day on the keto diet, although many opt to keep that number under 20 to achieve deeper ketosis. If you’re new to this diet, it may be helpful to measure your current carbohydrate intake using a diet tracking app to determine whether it falls between the 20 to 50 gram range. 

Remember that everybody is different, and your carbohydrate range may vary from someone else on the keto diet in order to maintain ketosis. You may want to play around with the <20 or 20 to 50 gram range to find the specific number to help you reach your health goal. 

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Consider Intermittent Fasting 

Another way to put the body into ketosis is to employ intermittent fasting, which works by causing the body to adapt to burning fat for fuel. This method involves a short period of time in which you can eat, which is called your eating window, followed by a fast for a longer period of time. 

There are different ways to approach intermittent fasting and the eating versus fasting windows. A standard split is called the 12/12, in which you can eat for 12 hours and fast for the other 12. 

Another common practice is known as the 16/8 split, in which you eat for eight hours and fast for 16. 

To help your body go deeper into ketosis, you may want to consider extending your fasting window. For example, if you’re fasting for 12 hours, try extending that to 14 hours. Many people opt to skip breakfast as it overlaps with their fasting window, and choose to have their first meal later in the day. 

Work with your nutritionist before implementing this practice to find an optimal fasting window or split for you.

Exercise More 

There is some evidence supporting the idea that exercise can increase ketone production. If you’ve not reached ketosis by restricting your carbohydrate intake, practicing intermittent fasting, and have tried logging your meals to see if a certain food may be the culprit, exercise may be helpful.

Endurance training such as biking, swimming, and running may be especially beneficial to help you increase ketone levels. You can also try incorporating a variety of different exercises such as weight training, cardio, and increasing your daily physical activity. 

How Does Exercise Affect Ketone Levels? 

So, how exactly does exercise affect ketone levels? The answer is still a little unclear. 

Exercise can temporarily reduce ketones or halt ketogenesis as the body is going to use the glucose as energy instead. This tends to be a temporary effect as the body uses immediate energy for your workout, and ketones usually go back to normal ranges a few hours after exercise.

One study demonstrated that exercise does appear to increase blood ketone production, but that increase doesn’t result in greater beta oxidation. This suggests that while exercise increases ketone levels, it’s not a long term or effective solution to moving the body into ketosis and maintaining that state.

How to Measure Ketone Levels

There are a couple of different ways you can measure your ketone levels. The first, which we already touched on, is testing your blood (or serum) ketone levels using a ketone blood test. The second is testing urine ketone levels using a urine ketone stick test.  

The ketone blood test involves drawing blood from a vein, usually from inside the elbow or back of the hand.. The blood sample is then tested for ketone levels. 

The urine ketone stick test involves collecting a urine sample and using a testing strip to measure your ketone levels. Your doctor will be able to decipher the results for you, or if using a self test kit, you’ll want to follow the instructions and color key to determine what the results mean. 

Advantages of Each Test

The advantages to using a ketone blood test include: 

• Measures current blood ketone levels, giving a more accurate view on the state of ketosis.
• Fast, immediate measurement.
• Greater sensitivity and specificity (especially for detecting diabetic ketoacidosis).
• Quick results allow for timely changes to the management plan as needed. 

The advantages to using a urine ketone stick test include: 

• Painless and relatively cheap.
• Readings can be read off the bottle.
• No technical skill required for equipment. 

Disadvantages of Each Test

The disadvantages to using a ketone blood test include: 

• Potentially painful.
• Need staff and equipment to draw blood and get results.
• Meter may be inaccurate at readings if readings are outside the range it is designed for. 
• Other nutrients, such as vitamin C, may interfere with results.  

The disadvantages to using a ketone stick test include: 

• Ketone strips have a shorter shelf life.
• The reading is an average of urine ketone concentration since last void.
• Other nutrients, such as vitamin C, may interfere with results. 

How Often Should You Measure Ketone Levels?

As you start the keto diet, you may want to monitor your ketone levels more frequently to determine if you’re entering ketosis. 

For consistency, it’s best to monitor your levels first thing in the morning, or at the same time each day. Once you have reached this state, you may be able to monitor your ketone levels less frequently. 

It’s best to discuss with your nutritionist what frequency is best for you and your unique needs. Some may want to check their ketone levels every day while for others checking every couple of weeks may be better.