8 Signs and Symptoms You're in Ketosis

So you’re on a keto meal plan and hitting your keto macros, but are you still wondering whether or not you’ve achieved ketosis? Here’s how to tell whether or not you’ve made the official switch to burning more fat for energy.

How to Put Your Body into Ketosis

There are really two main ways to get into ketosis through diet:

  1. Fasting for an extended period of time
  2. Cutting your carb intake

While starvation is one way, it’s not exactly a sustainable option for the long haul. Thus, eating less carbs still remains the best approach. 

A keto diet plan is designed to push you into ketosis by shifting your macro balance towards high fat, moderate protein and very low carbohydrate. This provides an abundance of fat you can use for energy instead of carbohydrates which are used in a traditional diet.

Use this simple calculator to learn how many grams of net carbs you should be eating every day!

The Keto Flu

Achieving ketosis often involves a transitional period where your body switches over to ketones as the primary source of energy. And this process can include some uncomfortable symptoms frequently described as the “keto flu”.

However, having symptoms of the keto flu does not always mean you are in ketosis - it just means your body is re-prioritizing how it metabolizes food for energy.

Nutritional ketosis is only achieved once your body starts producing enough ketones to become the primary source of fuel for your muscles and organs. And more often than not, this occurs after keto flu subsides and can take anywhere between a couple days to a couple weeks depending on individual factors.

Stay in ketosis and get your keto meal prep down to a science with this FREE Keto Meal Prep Toolkit. Complete with custom keto macro calculations, food lists, and tips from the pros. 

How Do You Know You're in Ketosis?

Whether you encounter the keto flu or not, how can you tell that your body has switched to fat as your primary source of fuel? Here are some common symptoms of ketosis to look for, some desirable and some less positive.

1. Keto Breath

As ketone body production increases, acetone is exhaled through your breath, producing a fruity sent (2). If you notice this slight change, it could be a sign of ketones taking over. 

If the smell is bothering you, brush your teeth throughout the day or try sugar free mints and gum. 

2. Decreased Appetite

If you're finding your cravings are fading and you can go a little longer between meals without as much hunger, you could be in ketosis.

Although the mechanism behind this phenomenon is still being investigated, it is thought that fat supplies a more steady stream of energy than carbs and doesn't cause spikes in blood sugar. Additionally keto foods are satiating and ketosis may suppress hunger hormones (2). 

3. Increased Focus

While it is thought that starting a keto diet may result in a little brain fog from the "keto flu," settling into ketosis may actually help improve your mental clarity and focus.

Although research is still in its early stages around ketosis and brain health, you may find that your memory is sharper and your mood is a little brighter while on a keto diet (3,4). 

4. Better Workouts

Fat is a desirable source of long lasting energy for many endurance athletes, so it's no surprise that being able to metabolize fat more efficiently can support certain types of exercise. In fact, some research suggests that ketosis may provide athletes more energy and support recovery (5).

If you're finding you have more gas in the tank when it comes to your gym routine, this could mean you've become more fat adapted. 

5. Frequent Urination

As your body eliminates glycogen stores, this can pull a lot of water out of your muscles. Additionally, your kidneys tend to pump out more fluid while on ketosis (6,7,8,9).

Moreover, to help counteract dehydration it is often recommended to increase fluids when starting a keto diet. 

All of this combined can cause you to feel like you're running to the restroom more frequently.

6. Rapid Weight Loss

Calorie restriction still remains the only recognized approach to fat loss, but changes in body water weight can occur early on in low carb diets due to the fluid losses mentioned above (8,9). 

If you’re feeling less bloated or slightly leaner all of a sudden, you could be shedding some water weight. 

Of course, going keto can also mean major dietary changes for some people. If you typically ate a lot of sugary foods prior to your keto diet, it is also likely you are cutting a lot of calories and losing body fat in addition to water.

8. Ketones in Your Urine or Breath 

Ultimately, the most definitive way to determine whether or not you are in ketosis is to test your ketone levels!

Commercial ketone test strips are available for both blood and urine. Although, these tests primarily look at levels of AcAc (not BHB) and cannot measure the exact amount of ketones in your blood.

Regardless, they are a good indicator of whether or not you might be in ketosis, especially when coupled with other symptoms noted above. 

Most sources recommend a goal of 0.5 to 3 mM for weight loss on the ketogenic diet. It isn't thought that there is a benefit to going over 3mM and these higher levels can represent a state of starvation for some people (meaning you aren't getting enough food)!

The dangerous condition of ketoacidosis that occurs in diabetics often involves much higher levels of ketones, usually greater than 10 mM. 

Ketone Level Chart  
Normal Serum Levels <0.5mM
Desired Levels for Ketosis 0.5 to 3 mM
Ketoacidosis > 10 mM

 *Chart represents common ketone levels, but these can vary based on multiple factors. References: (25,26)



It can be difficult to asses whether or not you are fully in ketosis without a professional blood test, but using store bought ketone strips is the most convenient and affordable approach for most. Especially since both the symptoms and potential benefits of ketosis can vary from one person to the next.

Pay attention to how your diet is making you feel from the inside out. If you're feeling energized and staying on top of your calories, you're on the right track. And on the contrary, if you just can't seem to kick the keto flu or are finding that a ketogenic diet is not providing you what you had hoped for, it might not be right for you. 


Sticking to Your Keto Diet

Need help sticking to a keto diet? Make sticking to low carb eating feel like a breeze with our Registered Dietician approved Keto Shopping List.

Our Keto Shopping List has hundreds of keto approved foods to help you build a delicious meal plan. You'll get meal planning templates, tips from industry leaders, and the best proteins and fats to help you stay in ketosis.

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