How to know if you are in ketosis – 6 straightforward tips

So you’ve started the keto diet, but you’re probably wondering “How do I know if it’s working?”. Below I’ll share some tips and tricks that will show you how to know if you are in ketosis. Hopefully some of these methods will help you figure out if the keto diet is working for you!

1. “Keto Breath”

One of the most common side-effects of starting the keto diet is a change in your breath. Your friends and family might notice it before you do! Though it doesn’t happen to everyone, keto breath is a result of an excess of acetone in the bloodstream. Acetone is a naturally occurring ketone and a common byproduct of the keto diet, resulting from the breakdown of fatty acids. An increase in acetone can lead to breath that has a “metallic” quality to it, and it’s one way to tell if your keto diet change is taking effect.

Don’t worry though: keto breath won’t adversely affect your oral health, and can be remedied with sugar-free gum!

2. Increased thirst and dry mouth

As your body switches from burning carbohydrates for energy to burning fat for energy, you will naturally burn through any remaining carbohydrate reserves (in the form of glycogen) that your body has stored. The process of burning your glycogen stores for energy leads to a lot of water loss because stored glycogen retains water. This, in turn, can lead to symptoms of dehydration including thirst and dry mouth. Lots of people starting a keto diet for the first time notice that they can’t stop drinking water, and this is normal!

Just remember that it’s always important to stay hydrated, not just when you’re starting the keto diet. If you notice these symptoms, then that’s good because you’re probably on your way to ketosis – but go grab a glass of water!

3. Urine test strips – “ketostix”

This method is my personal favorite! Though there is a fair bit of controversy surrounding the use of “ketostix” products, I personally love to use them when I’m trying to get into ketosis. They are cheap, quick, easy, and visual – but it’s best to know the facts so that you can use this tool most effectively.

Ketone urine test strips are small, disposable test strips that measure levels of acetoacetate (a ketone body) in your urine. In the early phases of a keto diet when the body begins to produce ketone bodies, the levels of circulating acetoacetate rise and this can be easily detected with a simple urine test.

how to know if you are in ketosis ketostix

However, there is always some variation in urine tests that can stem from a few factors:

A. Hydration level

Your hydration status will affect the concentration of anything in your urine, ketones included. So a very hydrated person may have an apparently lower level of ketones, but they just have more water diluting it down. By the same token, a poorly hydrated person may seem to have a much higher level of ketones in their urine, when in reality it might be relatively low and they just need some fluids.

B. Fat adaptation

Fat adaptation is something that we will cover in a separate in-depth article, but briefly: over time on the keto diet the body will change its metabolism in subtle but powerful ways that lead to a state of “fat adaptation”. As a part of this process, the body can shift from production of acetoacetate (measured by test strips) to other forms of ketone bodies. So even though your test strips are showing “fewer” ketones, it’s just unable to detect all forms of ketone in your urine, leading to a false-negative. This is why I like to use test strips for the ketosis induction phase only.

C. Timing

When you take the test can also produce misleading results. If you’ve been in ketosis for some time, testing for ketones after a carb-rich meal/day could still produce a strong positive result – but this is simply because your body still has remaining ketones that haven’t been excreted fully. You’ll likely see a different result over time.

4. Rapid weight loss!

Possibly my second favorite way to know if you are in ketosis! As mentioned in #2, starting the keto diet can lead to a lot of water weight loss. Even if you stay adequately hydrated, you’ll probably still notice the scale move pretty quickly downward in the first couple of weeks after starting a keto diet.

This is sometimes called the “honeymoon” phase of ketosis, where the body excretes excess water that was stored in glycogen, leading to rapid weight loss.

There are two important things to note about this rapid kind of weight loss though:

  1. It only lasts for a short period.
  2. Eating too many carbs can pack the water weight right back on.

Since you’ll only be getting rid of a finite source of water, your weight loss, though rapid, won’t be so quick forever. After a brief period of weight loss you’ll probably notice your losses “stalling” on the scale. Don’t be discouraged by this! Sticking to the keto diet will still lead to pretty quick weight loss and eventually to pretty amazing appetite suppression (the easiest form of weight loss… effortlessly eating less).

Be careful though, because just as you stored water in glycogen before, you can and will do so again if you resume eating carbohydrates. It’s why I always say that “cheating” on a keto diet is not recommended. You might see the pounds of water weight pack right back on. Sure, if you enter ketosis again you’ll probably lose the pounds, but who wants to balloon up and down like that? Not me.

5. Blood testing – difficult but accurate

One of the more difficult methods of ketone testing is to use blood tests. This one isn’t for the faint of heart! A blood ketone monitor is definitely the most accurate way to test your level of circulating ketones, but it is also the most cumbersome and most expensive.

6. Increased focus and sustained energy

When your body switches over to a fat-burning state, it becomes more efficient at producing, storing, and utilizing ketone bodies for energy. This means that your brain will have an almost constant stream of available energy. As a result, many people on the ketogenic diet experience a sort of heightened mental state throughout the day. This state can enhance mentally strenuous activities and increase one’s overall focus and attention.

A constant supply of energy also means that the body is less likely to crash as it does following drops in blood sugar after a meal. So in a fat-burning state, you might notice that you have more energy throughout the day to stay engaged and focused.

Let’s review how to know if you are in ketosis:

  1. Keto breath – tangy and metallic. A result of acetone production, but can be controlled.
  2. Increased thirst and dry mouth – your body is flushing water stored in glycogen, so stay hydrated!
  3. Urine test strips – my favorite method: inexpensive, easy, reliable, and visual (just make sure you know the pitfalls).
  4. Rapid weight loss – losing that water weight is always hugely motivating!
  5. Blood testing – The hard (but accurate) way. Is it worth it? Probably not in my opinion.
  6. Increased focus and sustained energy – Enhanced and sustained mental focus, fewer afternoon crashes.

You’ll be on your way in no time!

Hopefully, some of these methods for detecting ketosis will work well for you! Just remember that results can vary from person to person – but if you’re eating fewer than 20g net carbs daily, you should be solidly in ketosis in no more than 48 hours. So don’t fret too much!

If you’re just getting started, check out our article on jumpstarting your keto journey!

If you have any questions or thoughts please leave a comment and/or check out our other articles all about keto!

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