Ketosis is the primary goal of the ketogenic diet. When you're in this metabolic state, your body is burning fat at a higher rate than usual. Ketosis also boosts mental agility, increases energy, and improves overall health.
For those just starting a ketogenic diet, knowing you're in ketosis is a great motivator to keep going. There are many ways you can test for ketosis but using blood ketone meters is the most reliable method so far. If you are considering buying a blood ketone meter for this very purpose, you're probably interested in learning more about using this device and where you can buy one.
In this article, we explain what a blood ketone meter is, how it works, and what benefits and setbacks you can expect. We’ll offer you a list of the top blood ketone meters on the market and tell you where to get them. We also go over two other alternative ketone testing methods. But first, let's start by talking a bit about ketosis and why you should test for it.
Ketosis is a metabolic state in which most of your body's energy comes from so-called ketone bodies, aka ketones. Ketosis happens when your body is metabolizing fat at a high rate than usual and converting the resulting fatty acids into ketones. There are three types of ketones that your body makes:
- Beta-hydroxybutyrate (BHB)
This metabolic switch to ketosis happens when your body is starved of glucose like during prolonged fasting or on a very low-carb, ketogenic diet. You can learn more about how to get into ketosis here.
In contrast to ketosis, your body normally runs on glycolysis where most of energy comes from glucose. Glucose is a simple sugar that circulates your blood and enters cells for energy production with the help of insulin. Adequate circulating glucose suppresses ketosis while higher than normal circulating glucose causes the body to convert and store some of it as fat.
When blood glucose levels drop, however, due to low carbohydrate intake, your body starts looking elsewhere for fuel. One place it goes to is your fat stores. What happens is that drops in blood glucose stimulate the release of hormones epinephrine and glucagon which cause fat oxidation to take place which leads to fat being released into the bloodstream. Once released fat reaches the liver, some gets converted into ketone bodies and your body starts to run on ketosis.
Benefits of Being in Ketosis
People go keto for the benefits, of course, and most of these benefits are directly linked to ketosis. Here are some of the countless ketosis benefits explained:
The most highly sought-after benefit of the ketogenic diet and ketosis is weight loss. Ketosis causes weight loss by stimulating fat oxidation and suppressing fat synthesis and storage. Studies also show that, unlike other weight-loss diets, the ketogenic diet does not decrease your resting metabolic rate (RMR) .
Your RMR is the rate at which your body burns calories at rest. The higher the rate, the easier it is to maintain or lose weight and that’s why it’s so important for weight loss. Unfortunately, weight-loss often causes a drop in RMR as an attempt to spare energy supplies. Luckily, the keto diet has a minimal impact on RMR which explains the sustained weight loss people experience when in ketosis.
Ketosis means your body is running on a more efficient fuel source than glucose — ketones. Studies show that ketones provide more energy per unit of oxygen used than glucose or even fat . Furthermore, ketones have a higher caloric value than either protein or carbs at roughly 5 calories per gram.
Ketosis also does not rely on a constant influx of food in order to keep fueling your body. That's not the case with carbs and sugar. You're probably familiar with how sugar gives instant energy but also causes energy slumps later on. That's not the case with ketosis. In this state, energy flow is steady and constant.
Ketone bodies are nature's nootropics. Studies have long documented their positive impact on the brain, with some showing that ketones reduce seizure frequency, slow-down Alzheimer's, and heal the brain from traumatic injury .
In those not suffering brain diseases, however, ketones boost mental acuity, memory, and overall mental energy. These effects likely come from the antioxidant action of ketones. Ketones namely improve mitochondrial functioning by lowering the production of reactive oxygen species (ROS). However, researchers are still trying to explain the whole scope of positive effects that ketones have on your whole central nervous system.
Other notable benefits of ketosis include diabetes control, reduced risk of cancer, lower inflammation, reduced risk of cardiovascular diseases, and much more.
Measuring Ketosis with a Ketone Meter
Now that you're familiar with ketosis and its benefits, you probably want to know when you’ve reached this magical metabolic state of effortless fat burning. There are several ways to do that but the most reliable ketosis measuring tool is a blood ketone meter.
A blood ketone meter is a device similar in appearance and function to a glucose meter. These devices have a digital display showing accurate readings described in mmol/L. People with diabetes use this device to make sure their ketone are not at dangerously high levels which leads to a condition called ketoacidosis*. Those on a keto diet, however, use it to see if they're in ketosis.
A reading of 0.5 to 3.0 mmol/L means you are definitely in ketosis, while a reading below 0.5 mmol/L means you're not in ketosis. Anything above 3.0 mmol/L is a sign of ketoacidosis and needs immediate medical attention.
*Ketoacidosis is a state of uncontrolled ketone production and where ketone bodies reach dangerously high levels. Healthy people are unlikely to ever experience ketoacidosis. This problem is more common in those with type I diabetes and other medical conditions like alcoholism.
Using a Blood Ketone Meter
A blood ketone meter usually comes with a lancet pen and test strips. For some meters though, you may need to purchase the test strips separately.
To start using a blood ketone meter, take the following steps:
- Start by placing a needle in the lancer pen according to packaging directions.
- Wash your hands with soapy water to prevent infections.
- Remove a test strip from the package and place it into the blood ketone meter.
- Poke the tip of your finger (preferably left index finger) and squeeze out a drop of blood. You'll need a larger droplet for the test strip to absorb it properly.
- Now touch the end of the test strip with your index finger to let the strip absorb the blood.
- The blood ketone meter will give you your reading within a few seconds.
Depending on your readings, you may need to take some necessary steps, considerations, diet tweaking, or just see it as reason to celebrate that you're finally in ketosis. In case you’re curious, here’s what guidelines say about different blood ketone readings :
- 0.6 mmol/L to 1.0 mmol/L – normal for most people and those not on a keto diet.
- 1.0 and 1.5 mmol/L – means you're in ketosis. If you're not on a keto diet but are diabetic, this reading means you need to call your doctor.
- 1.5 and 3.0 mmol/L– Optimal ketosis is 1.5 mmol/L while readings above 3.0 mmol/L are unnecessary and risk for diabetics.
- 3.0 mmol/L and above – These are unhealthy levels even for healthy people.
Advantages of Blood Ketone Meters
Blood ketone meters are more accurate than other ketone measuring tools and methods. In fact, blood ketone meters are considered "the gold standard" of ketone testing. Here are the top reasons blood ketone meters outweigh other ketone testing methods:
- Blood ketone meters measure both acetones and B-hydroxybutyrate (BhB). These are most abundant ketone bodies found most of the time in the blood and considered stronger indicators of ketosis.
- Drugs and other substances don't affect the results of blood ketone meters.
- Blood volume is normally at stable levels which means that the chances of changes in blood volume affecting ketone concentration results are minimal.
Blood ketone meters also give accurate results within seconds. But there are disadvantages to these devices. Blood ketone meters tend to be pricey with an average price of around $100. You also need to purchase new testing strips further adding to the cost of testing blood ketones.
Are Blood Ketone Meters Necessary?
Whether a splurge on a ketone meter is worthwhile for keto dieters is a matter of debate. You really don't need to test for ketosis and ketone levels if you're simply looking to lose weight or feel better through keto. However, if you're an athlete or suffer type I diabetes, blood ketone meters are a valuable tool.
For athletes, who need to tweak their keto diet to suit their unique lifestyle and physical demands, blood ketone meters help. For example, they help keep a track of ketone levels during carb cycling helping athletes determine their carb load threshold before they get kicked out of ketosis.
Doctors also encourage patients with type I diabetes to test for ketones when they're feeling unwell. Testing ketone levels when you have type I diabetes becomes especially important on a ketogenic diet. That's because insulin, which is deficient in type I diabetes, controls ketone level production so it doesn't go haywire.
There are many different brands of ketone meters on the market. But to get the best bang for your buck, go for these three meters that you can purchase on Amazon:
Abbott Diabetes Care developed this high-precision meter complete with a backlight display. It can store up to 450 measurements and even display your blood glucose averages. The device requires that you enter a code to switch from glucose to ketone testing.
The strips used with this blood ketone meter require 1.5 microliters of blood. Studies comparing different blood ketone meters found the Precision Xtra to be among the most accurate . So if you’re looking for reliability and precision, Precision Xtra is your best pick.
Nova Max Plus
Developed by Nova Biomedical, you can get this blood ketone meter for free if you purchase two boxes of test strips from this company coming at around $25. The device is easy to use and does the thinking for you. If you're a diabetic measuring blood glucose, the device reminds you to test ketones when your levels exceed 250 mg/dl.
You also don't need to enter a code to switch between glucose and ketone testing. That happens automatically depending on which test strip you insert. However, the Nova Max Plus is less precise than the Precision Xtra but also much cheaper. It also requires just 0.3 microliters for testing.
Keto Mojo Ketone Meter
Keto Mojo came out just recently but is already taking the keto products market by storm. The product comes with everything you need to start testing ketones: a lancet device, ten lancets, and ketone test strips.
The manufacturers claim that this blood ketone meter is one of the most accurate on the market. Besides testing for ketones, the device also measures glucose, hematocrit, and hemoglobin. It features a large LCD screen with backlight. But one of the things that makes this device especially worthwhile is that it is FDA approved.
If you don't feel like throwing money at a blood ketone meter but still want to test for ketosis, there are a couple of cheaper alternatives out there:
But once you become keto-adapted, your body becomes more efficient in utilizing ketones and fewer get lost through urine. This means that test strips will no longer detect ketones despite you being in ketosis.
It's best to use urine test strips early in the morning when ketone levels are highest for accuracy. Keep in mind though that urine can become diluted when you drink lots of water and this will affect your results. Certain drugs can also create false positives with urine test strips .
Ketones exit your body through breath as well. A ketone breathalyzer device can detect the number of ketones in your breath. This device is less accurate than a blood ketone meter but more accurate than urine test strips. They're also quite cheap with prices averaging around $15.
According to current research, breath ketone levels directly correlate to blood ketone levels in the early stages of ketosis . The ketone body released through breath is acetone specifically. This ketone body is quite volatile with a fruity odor that many dieters also notice on their breath when first entering ketosis.
Looking for Ketosis Signs
The cheapest way to test if you're in ketosis is to eyeball it by looking at your signs and symptoms. You won't know the exact levels of ketones in your system this way or anything about how your body is utilizing them. However, what you will know is that these signs mean you definitely are in ketosis. If that's all that matters to you, see if you are experiencing any of the following:
1. Keto breath
We already mentioned this one briefly when talking about keto breathalyzers. Keto breath is a fruity-smelling breath that some describe as resembling nail polish remover. Dieters also describe it as smelling like overripe fruit. But one common characteristic of this breath is that it's strong and unpleasant.
Keto breath is the result of your body breaking down BHB. The breath goes away as soon as your body becomes more efficient at using the ketones that it is making. But until that time, you may want to rely on bubble gum or breath fresheners throughout the day.
2. Keto Flu
When people first start the keto diet, they often lose a lot of water weight and electrolytes. This often leads to flu-like symptoms popularly termed "keto flu." These symptoms include headaches, nausea, muscle pain, fatigue, and brain fog.
However, it's important to note that these symptoms are not a result of rising ketone levels. They're simply the side effects of carb withdrawal. The reason they're important is because you can expect ketone levels to rise once your glucose levels drop so low to cause the keto flu. To learn more about the keto flu and ways to alleviate it, click here.
3. Increased Energy
Ketone bodies are a more efficient source of energy than glucose. That's why you'll definitely feel a burst of energy once you get over the keto flu. Keto dieters feel that they can do so much more when in ketosis and with greater energy.
However, this new supply of seemingly endless energy can also cause sleep problems. Many dieters report having trouble falling and staying asleep as a result. Luckily, this also goes away when you become keto-adapted and evidence even shows that sleep improves while you're in ketosis .
4. Weight Loss
In the first week of going keto, you will notice the number on the scale drop by 1-3 pounds. However, this is only water weight. But if you continue to lose weight in weeks two, three, and further on, that means you're in ketosis and losing fat.
For your body to make ketones, it needs to burn fat. If your calorie intake is low enough to present an energy deficit, your body has no choice but to turn to its fat stores to make ketones. This weight loss tends to be steady on a keto diet for up to 6 weeks, after which time most people experience a bit of stagnating.
5. Reduced Appetite
Another reason you can expect to lose weight when in ketosis is due to appetite reduction. Ketones themselves have a natural appetite suppressing effect . This effect is due to ketones suppressing ghrelin, the appetite hormone.
But the keto diet also suppresses appetite because you're eating more satiating fats. You'll especially notice this if you add MCT and coconut oil to your diet as studies show that MCTs are much more satiating than long-chain fatty acids .
When it comes to testing overall ketone levels, blood ketone meters take the lead in terms of efficiency and accuracy. But these devices are pricey and invasive even. That's exactly why many keto dieters like to look for alternatives to a blood ketone meter to find out if they're in ketosis.
Whether you should go for these high-precision devices to monitor your exact ketone levels daily or go for cheaper, but less accurate, alternatives depends on what you're trying to achieve. An average keto dieter who's after weight loss doesn't need a blood ketone meter to stay in ketosis. An athletic type who likes to carb cycle or someone with type I diabetes will benefit greatly by using these devices.
Once you make your choice, go for quality products. That way, you'll get the bang for your buck and won't need to worry about test result accuracy. And if you want to learn more about the signs of ketosis, read our article here.