Besides the incredible benefits, sometimes it can be challenging for keto newbies to figure out when their body starts going through ketosis (when a body burns ketones instead of glucose), especially if the diet is relatively new. This high-fat, low-carb diet (learn more the Body Reboot book), initially requires a lot of diligence to cut down carbs for the body to reach ketosis. However, after that point, the diet should become a lot easier since the body will feel fuller from consumed protein and fats. To figure out the signs that’ll tell you whether your body is in ketosis experts and bloggers weigh in on what to look for below.

You’re Losing a Lot of Water Weight

Insider says that initially, it’s common to lose a lot of water weight, but don’t fret because soon additional weight loss will follow. It’s encouraging to see the weight come off and then continuing to have it come off urges you to keep pressing on!

“When you first go on the keto diet, you will lose a lot of water,” Masson suggested. The storage form of sugar (glycogen) needs three molecules of water for every molecule of glycogen, she said, and when your body starts to use up the stored water, you will urinate more causing your total body weight to go down.

Eventually increased fat loss will also be a source of weight reduction, she added.

You’re Really Tired

When your body transitions into ketosis it’s making a massive switch from surviving off fat instead of carbohydrates. Thrive Strive says don’t be surprised if you feel exhausted. You may feel so tired that you might even feel like you have the flu. They call this the “keto flu” because your body is adjusting from burning carbs to burning fat. Hang in there because if you stick to the diet your fatigue should lessen and there are also some ways to counteract the keto flu. Thank goodness!

Wait, what?

We just talked about increased energy and now we are talking about fatigue.

The problem with switching over to the keto diet is that your body has to completely transition over.

During this transition, your body is looking for glucose and when it doesn’t have it, it isn’t quite ready yet to produce enough ketones to sustain you.

Your body is also releasing a lot of electrolytes through urine that you aren’t used to replacing. Hint: If you aren’t in ketosis yet it might be because you aren’t drinking enough water.

To fight the short-term fatigue and get over this initial hump simply make sure that you are replacing all of the electrolytes that your body is losing.

You can do this with specialized drinks and supplements or make sure you get them in the foods that you eat.

If you go the supplement route be sure that you are taking 2,000 – 4,000 mg of sodium, 1,000 mg of potassium and 300 mg of magnesium.

You Don’t Have an Appetite

When you first start keto, you may find you don’t have an appetite, which is partly due to cutting out carbs and partly due to your body getting used to a brand new way of fueling itself. Going forward your appetite should come back, but still help you feel satiated. The Daily Nutrition discusses more on not having an appetite on the keto diet:

Funny thing about cutting carbs from your diet, you start to lose your appetite. You just don’t get as hungry as you used to be.

Don’t get me wrong, you won’t lose your appetite altogether, but it will take hours and hours before you start to feel that hungry feeling. There won’t be any worry for a snack an hour after your lunch break.

When you are eating, you are more than likely not going to overeat. Overeating is a problem that many people face without realizing it. A keto diet causes your body to have a satiated feeling for a much longer time.

This is a big reason for not having as much of an appetite.

You Have Bad Breath

Another sign you’re in ketosis or getting close? You have bad breath. Yes, it’s pretty funny that you may get bad breath, but if you’re healthier and losing weight it’s worth it, right? Just chew on some gum, and you’ll be as good as new. See what else Healthline has to say about bad breath:

People often report bad breath once they reach full ketosis.

It's actually a common side effect. Many people on ketogenic diets and similar diets, such as the Atkins diet, report that their breath takes on a fruity smell.

This is caused by elevated ketone levels. The specific culprit is acetone, a ketone that exits the body in your urine and breath.

While this breath may be less than ideal for your social life, it can be a positive sign for your diet. Many ketogenic dieters brush their teeth several times per day or use sugar-free gum to solve the issue.

If you're using gum or other alternatives like sugar-free drinks, check the label for carbs. These may raise your blood sugar levels and reduce ketone levels.

You Are Thirsty

In addition to bad breath, The Keto Summit mentions you may also experience a dry mouth and find you are thirstier than usual. That’s a good sign you’re in ketosis or almost there. It’s important to stay hydrated and make sure you have enough salt and electrolytes in your system to avoid the keto flu as we mentioned earlier.

Many keto dieters report having a dry mouth and feeling a lot thirstier than usual. If that’s something you’re experiencing, don’t worry. It’s a sign your diet is working!

When you’re in ketosis, you’ll be excreting a lot of water – that’s one side effect of switching to a diet high in fat and protein, but low in carbs. And you’ll be losing a lot of electrolytes (like sodium, potassium, and magnesium) along with the water.

You’ll not only be losing more sodium than before, you’ll also be eating less sodium than before. And that’s because you’re giving up processed foods. Think about how salty a bag of chips is – most highly processed foods have a lot of sodium in them. And when you cut those foods out of your diet, you’re also cutting out your main source of sodium.

This combination causes a drop in your electrolyte levels and the amount of fluid in your body. So you start feeling thirsty!

You’re Having Issues Sleeping

Having issues getting quality shuteye? Initially, another sign you’re headed into ketosis or are already there is that you’re having problems sleeping. Don’t worry though because this is entirely normal. When you’re cutting back on carbs at first, your cortisol may be out of whack, which means it can affect your sleep. In a week or so, depending on your body, you should be back to normal.

Because of biochemical changes happening in your body, Masson suggested that stress can actually cause your body to produce cortisol (a stress hormone which causes sleep disruption) before your body starts producing and using ketones efficiently.

This may cause some sleepless nights when you first start the diet, she said.

You Have More Ketones

Healthline tells us about another good sign you’re in ketosis – your bloodstream shows you have a lot of ketones! The more ketones your body has, the more likely your body is experiencing ketosis and is now burning fat instead of glucose. Learn how to test your ketone levels and what else it means.

One of the hallmarks of a ketogenic diet is a reduction in blood sugar levels and an increase in ketones.

As you progress further into a ketogenic diet, you will start to burn fat and ketones as the main fuel sources.

The most reliable and accurate method of measuring ketosis is to measure your blood ketone levels using a specialized meter.

It measures your ketone levels by calculating the amount of beta-hydroxybutyrate (BHB) in your blood.

This is one of the primary ketones present in the bloodstream.

According to some experts on the ketogenic diet, nutritional ketosis is defined as blood ketones ranging from 0.5–3.0 mmol/L.

Measuring ketones in your blood is the most accurate way of testing and is used in most research studies. However, the main downside is that it requires a small pinprick to draw blood from your finger.

What’s more, a test kit costs around $30–$40, plus an additional $5 per test. For this reason, most people will just perform one test per week or every other week.

At the time of writing this post, we're currently giving away free copies of the Body Reboot book because it's our mission to increase awareness and to help people lose weight and get healthy! If you help us cover the cost of shipping, we’ll send a copy to your door FREE. Go over to this page to see if there are any copies left.

Sources: Insider, Healthline, Thrive/Strive, The Keto Summit, The Daily Nutrition