The keto diet is a popular way to lose weight and get healthy. A key aspect of doing this is simply staying in ketosis. But, knowing when you’re in ketosis isn’t always easy.
Beginners often struggle with this area. After all, the signs of ketosis aren’t always obvious. This post addresses that topic and shows you how you can find out if you're in ketosis, along with why testing for ketosis is so important.
To do so, we’re highlighting the four main testing techniques (yes, four!) and how they compare to each other.
What is Ketosis?
Ketosis is a biological state, where your body is burning fat for fuel, rather than carbs. This process produces compounds known as ketone bodies – or simply ketones.
Those ketones are responsible for some of the benefits associated with ketosis.
As we spend time in ketosis, our ketone levels increase. Tracking this change is an effective way to know when we are in ketosis.
For most people, the ultimate goal is to become keto-adapted or fat adapted. This is when your body is familiar with burning fat for fuel – and you’ve got past the initial keto flu. At this point, you see more benefits of ketosis, including improved weight loss and increased energy.
As the site Very Well highlights, keto adaption does take time. So, you need to be patient.
Testing for Ketosis - Why Bother?
In theory, you shouldn’t need to do any testing at all. If you’re following a keto diet without any deviations, then you should naturally be in ketosis.
For that matter, many long time keto dieters don’t test their ketone levels often, if at all. They simply don’t need to. Instead, they can often tell whether they’re in ketosis by the way that their body responds.
But, learning your body like that takes time.
Testing ketone levels is a powerful way to keep yourself on track, especially at the beginning. This also lets you see what is working and what isn’t.
Doing so is critical – because carbs are hidden everywhere (as the site Low Carb Zen explains). It’s easy to kick yourself out of ketosis without even realizing it, regardless of how carefully you plan. Testing your levels lets you get around this issue and helps you to stay in ketosis.
Simply put, testing your ketone levels is the best place to start. You might stop doing this later on (or not). But, either way, the process is a critical early guide.
How to Test for Ketosis
There are four basic ways to test your ketone levels. These are:
- Ketone Blood Meters. These use levels of beta-hydroxybutyrate in your blood to measure ketone levels
- Breath Analyzers. These look at acetone levels in your breath
- Urine Strips. These measure acetoacetate levels in your urine
- Keto Symptoms. You can also just rely on the symptoms of ketosis and some people do
Each style works, to some degree. But, each has advantages and disadvantages to consider. And okay, the last one isn’t technically a type of testing. It does perform the same role though and is worth discussing.
Ketone Blood Meters
Blood meters are similar to the devices used to test blood glucose levels. To use one, you insert a testing strip into the meter, prick your finger and place some blood on the strip. This then gives you a reading of your ketones, based on the beta-hydroxybutyrate levels.
The idea can sound difficult and painful – but it’s not. The devices are typically simple to use. You can (and should!) use lancets to make the process of getting blood fast, safe and easy.
You’re not drawing much blood and the process just feels like a pinprick.
The main advantage is that blood meters are accurate. In fact, they’re the most reliable option and they give you consistent results.
Of the three options, they’re also the easiest to use in public. After all, diabetics regularly test their blood sugars when they’re out. In contrast, blowing on a breath meter is easier, but it can look a little odd.
Even so, blood meters are expensive and they can be frustrating.
- You have to pay for the meter itself (like this one here). They’re not cheap and aren’t as reliable as they could be. Ketone blood testing is also a fairly new and narrow field, so there aren’t that many reliable brands out there.
- You have to buy new testing strips regularly. These can be purchased individually, but they are pretty expensive as well. You also need to make sure they’re compatible with the meter.
- You may need buy lancets often too. These are much cheaper, but they’re one more thing to buy.
And honestly, many of us don’t like the idea of regularly drawing blood, regardless of how small the amount is.
A ketone breath analyzer simply considers the level of acetone on your breath. These are often expensive and they tend to get mixed reviews. You would need to shop around to find a reliable brand.
Breath analyzers are easy to use. You just need to turn the device on and breathe into it (the duration will depend on the product). That’s it. There are no test strips to worry about either.
Because this is a one-time purchase, breath analyzers can be cost-effective. Even so, make sure you choose a good brand. Some of the cheaper ones won’t be as reliable or will break quickly.
As for testing ketones – analyzers are somewhere in the middle. They’re less reliable than blood meters and more reliable than urine testing strips.
They’re also the easiest to use, which is a major advantage. But, there are limitations too.
- There hasn’t been as much research on these – so we don’t fully know how accurate they are
- The measurements are often non-specific
- They can take a while to use
- There isn’t much information to help you figure out which brands are reliable
Urine strips are the least reliable option. But, they still have their place.
These simply look at the level of acetoacetate in your urine. The strips are very simple to use, although there are a few steps involved. The general idea is as follows:
- Collect a urine sample in a clean container
- Dip the strip into the liquid briefly (typically a few seconds)
- Shake off any excess and then wait for the strip to develop
You can then compare the results to the color chart that the company provides. Each brand will also have more precise instructions, including how long you need to wait for the strip to develop.
The color charge varies a little between companies. But, this image shows one example.
By comparing your color to the chart, you can get a rough indication of your ketone levels. The system isn’t precise and doesn’t provide an exact number. Still, it is good enough for many situations.
The video below also shows what you can expect.
There are some key advantages to urine strips.
- They are inexpensive. For example, the strips from Perfect Ketone cost less than $10, receive good reviews and provide you with 100 strips per container. So Nourished also offers testing strips that are a powerful choice.
- They’re easy to use. Sure, having to take a urine sample is annoying. But, it’s not difficult.
- They’re reliable enough. Urine strips are the least reliable way to measure ketone levels. Even so, they’re effective when you are first entering ketosis. They can help you track progress and see what is working and what isn’t.
But, urine testing strips are always limited. Urine is never an accurate indication of the body processes anyway. That issue is why the alkaline diet is such an absurd idea as well.
For ketosis, the strips only test the ketones that our bodies don’t use. This technique offers a rough indication when you are first starting ketosis – and is good enough.
If you are just beginning, you could check out the keto beginners guide that ruled.me provides or our Understanding the Ketosis Diet post. These offer all the information you need to get started, along with details about many of the resources for supporting your journey.
Urine strips are typically inaccurate once you’re keto-adapted. This makes them most suitable for the early stages of ketosis. After that, you’ll want to turn to something more reliable.
They can also be messy. Having to collect and test a urine sample regularly isn’t the most attractive concept either.
This final technique doesn’t directly test whether you’re in ketosis. But, it’s still used as an option for many keto dieters. The idea is to rely on symptoms to monitor whether you are in ketosis.
Doing so can work, as there are various signs of being in ketosis, such as increased energy once you're keto-adapted.
Once you’ve been following the diet for a while, those symptoms become easier to spot. But, even so, be careful. Most symptoms of keto adaption (like weight loss or extra energy) are subjective. It’s easy to interpret your responses based on what you want to see, not what is actually happening.
- If you’re just starting ketosis. Stick with one of the other testing mechanisms. You need to know how your body responds to ketosis and knowing your ketone levels will help you to do that
- If you’re keto-adapted. Try decreasing how often you use ketosis testing tools. Relying on them periodically may still be useful, but you shouldn’t need to use them daily
- If you’re a long time keto dieter. You do you. Some people continue to rely on ketone testing, others don’t
Relying on symptoms may also be fine if you’re just interested in some of the benefits of keto. If you just want to lose a little weight or improve your diet – being in ketosis constantly isn’t essential.
For example, an article on the site Mark’s Daily Apple suggests that many people may benefit from being in a keto zone, rather than following ketosis strictly. The idea won’t suit everyone – but it is an alternative to consider.
If nothing else, relying on symptoms means you’re avoiding any obsession with numbers. Doing so can be good for promoting a long-term healthy relationship with food.
The Best Ways to Test for Ketosis
Each method of testing has some good points and some bad ones. The best approach is going to depend on what you want and need.
- Ketone Blood Meters. The most accurate technique. They’re also expensive and you need to buy new testing strips often
- Breath Analyzers. Worse than blood meters but better than urine strips for accuracy. They can be expensive, but it is a one-time cost. Just make sure you choose the brand carefully
- Urine Strips. Cheap but not very accurate. They can be useful right at the beginning of your ketosis journey but not once you are fat-adapted
- Keto Symptoms. This is the least reliable technique, by far. But, it can be effective if you’ve been following ketosis for a while or just want to get into a keto zone
Testing your ketone levels isn’t essential. If you only want some of the benefits of ketosis or want to lose some weight – you could skip testing entirely. Or, you might use urine strips at the start and then rely on what you’ve learned.
But, if you want to be certain you’re always in ketosis, you should consider a breath analyzer or blood meter. Both are fairly accurate ways to measure ketones and can help you make the right decisions. Of the two, the blood meter is the most reliable and has been researched more.
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