Table Of Contents

Introduction: What is Ketosis & Why is it Important?

Ketosis is a metabolic state in which the body burns fat for energy instead of carbohydrates. This process occurs when the body is in a state of low carbohydrate intake, such as when following a low-carbohydrate diet or fasting.

When the body is in ketosis, it produces molecules called ketones, which are used by the body as an alternative energy source. This is in contrast to the normal state where the body primarily uses glucose from carbohydrates as its primary source of energy.

Ketosis has been shown to have several health benefits, including weight loss, improved insulin sensitivity, and increased energy levels. It may also have potential therapeutic benefits in treating certain neurological disorders like Alzheimer’s disease.

However, it is essential to note that achieving and maintaining ketosis requires careful attention to food intake and may not be appropriate for everyone. Therefore, it is important to consult with a healthcare professional, a registered dietitian, or a physician, before embarking on a ketogenic diet or any significant dietary changes.

How Long Does it Take to Enter Into Ketosis

What Are the Signs You Are in Ketosis?

Ketosis is a metabolic process where the body uses fat as its primary fuel source instead of carbohydrates. Although ketosis may be beneficial, it’s important to know the signs of ketosis. 

The most common sign of ketosis is an elevated level of ketones in the blood, which can be monitored with urine or blood testing strips or breathalyzers. 

Other indicators may include increased energy levels and improved mental clarity, changes in appetite and cravings, loss of extreme hunger, taste bud changes, and bad breath. 

Additionally, some people may experience side effects such as nausea, vomiting, headache, fatigue, dizziness, insomnia, difficulty in exercise tolerance, and constipation, sometimes referred to as keto flu.

Here are some common signs you are in ketosis:

  • Increased ketones in the blood: One way to confirm if you are in ketosis is to measure your blood ketone levels. This can be done using a ketone meter or through urine test strips.
  • Reduced appetite: People in ketosis may experience a decreased appetite which may be helpful for weight loss.
  • Increased thirst: The body uses more water when burning fat for energy so you may feel thirstier than usual, so stay hydrated.
  • Bad breath: Some people experience bad breath which is a result of increased ketone production.
  • Fatigue: It is common to experience this during the first few days of ketosis as the body adjusts to using fat for energy instead of carbohydrates.
  • Increased focus and energy: Many people report increased mental clarity and focus when in ketosis, as well as a boost in energy levels.
  • Changes in digestion: Some people experience changes in digestion such as constipation or diarrhea during ketosis.

Remember everyone’s experience with ketosis may be different, and it is crucial to monitor your body and consult with a healthcare professional if you have any concerns.

What Are the Benefits of Being in Ketosis?

Weight loss

The ketogenic diet has been used as an effective weight loss and management tool. At its core, the diet involves restricting carbohydrates so the body burns fat instead. This decreases the body’s general store of fat leading to potential weight loss, particularly in the first few weeks. 

Being on a ketogenic diet also means there may be increased energy when burning fat. 

Improved blood sugar control

Ketosis can be an addition to the treatment plan of someone with diabetes, as it has been shown to improve insulin sensitivity and aid in regulating blood sugar levels. Ketosis happens when a person follows a very low carbohydrate diet which is between 20 and 50 grams of carbs per day. 

As carbohydrates are broken down and metabolized into glucose, this triggers an increase in insulin production. When following a ketogenic diet, the body learns how to look for alternative fuel sources, such as fats and proteins.

Studies show that when combined with exercise and other strategies, ketosis may be beneficial for managing diabetes.

Increased energy

For many people, ketosis can be an effective tool for achieving improved overall health. Characterized by the body’s ability to burn fat quickly and efficiently as its primary energy source, ketosis has been associated with providing certain individuals with more focus and energy throughout the day. 

As opposed to relying on carbohydrates for fuel, transitioning to a state of ketosis involves limiting carbohydrate intake in favor of proteins and fats. 

Improved mental clarity

Research has revealed that limiting your carbohydrate intake, becoming “fat-adapted,” and entering a ketogenic state may help us in this regard by improving mental clarity and focus. 

According to the Cleveland Clinic, research suggests our brains work more efficiently on ketones than on glucose.

Certain health benefits of the ketogenic diet include improved energy levels, reduced hunger cravings and unwanted snacking, as well as an improved metabolic state shifting to a greater reliance on fat for fuel, rather than sugar. 

Also, read – Fasting for Mental Clarity

Reduced inflammation

Ketosis may lead to improved metabolic health, which is beneficial for people who suffer from chronic inflammatory conditions. 

The key to reducing inflammation with ketosis lies in the unique metabolic state it creates, allowing your body to use fat reserves as fuel efficiency and decreasing your overall reliance on glucose. This shift in metabolism makes ketosis an attractive intervention strategy for those looking to manage their inflammation naturally and effectively.

Reduced risk of heart disease: Some research suggests that ketosis can improve cholesterol levels and reduce the risk of heart disease.

Potential therapeutic applications

The potential applications of ketosis to treat neurological disorders is an area of rapidly growing interested. While the mechanisms and effects are not yet fully understood, researchers have found that a state of ketosis can be beneficial in managing conditions such as Alzheimer’s disease and other mental health conditions

By doing so, ketosis provides an alternative to traditional treatments, allowing for improved management of symptoms without adverse side effects commonly associated with pharmacological interventions. As research advances and understanding increases, ketosis may become a more frequently applied treatment option for neurological disorders.

How Long Does It Take to Reach Ketosis?

The time it takes to reach ketosis can vary depending on different factors including your current eating pattern, activity level, and metabolism. However, most people can expect to enter ketosis within 2-7 days of starting a low-carbohydrate diet.

How long does it take to achieve ketosis? 

It generally takes 2-4 days to enter ketosis if you consume between 20 and 50 grams of carbohydrates in a day.  Some individuals may take longer depending on age, metabolism, and the number of carbs, fat, and protein ingested prior to starting a ketogenic diet.

Decreasing carbohydrates forces the body to start breaking down stored fat for energy which produces ketones in the process. However, it’s important to note that the exact threshold for entering ketosis can vary from person to person.

  • It’s also important to note that the process of becoming fully keto-adapted, meaning the body is fully adjusted to burning fat for energy, can take several weeks. 

During this time, you may experience symptoms such as fatigue, headaches, and digestive issues as your body adjusts).

Also, read – Signs of Autophagy: Health Benefits & Symptoms

Does Ketosis Make You Tired?

It is common for people to experience fatigue or a decrease in energy levels when first starting a ketogenic diet, which is sometimes referred to as the “keto flu.” This short-term side effect typically lasts a few days to a week as the body adjusts to burning fat for fuel instead of carbohydrates.

Some people may experience fatigue, headaches, nausea, or dizziness during this time. These symptoms can be caused by a lack of carbohydrates, which the body typically relies on for energy.

Once the body adjusts to using fat as its primary fuel source, many people report feeling more energized and focused. However, if you continue to experience persistent fatigue or other concerning symptoms, it’s essential to speak with a healthcare professional to rule out any underlying health conditions.

It’s also important to ensure that you’re getting enough essential nutrients, such as fiber, vitamins, and minerals. 

How Can I Get Into Ketosis More Quickly?

Here are some tips that may help you get into ketosis sooner:

1. Reduce your carbohydrate intake 

To enter ketosis, you typically need to consume fewer than 50 grams of carbohydrates per day.

2. Increase your healthy fat intake

In a ketogenic diet, fat should make up the majority of your caloric intake. Therefore, consuming more healthy fat such as olive oil, avocados, nuts, nut butter, meat, eggs, fatty fish and seeds can help keep you feel full and satisfied while also providing important nutrients. This can help you enter ketosis more quickly.

3. Moderate your protein intake

Consuming too much protein can inhibit ketosis. So it’s important to ensure protein intake is moderate and does not exceed your body’s needs. This is typically not more than 1 gram of protein per pound of body weight.

4. Try intermittent fasting

Fasting may help deplete glycogen stores in the liver and accelerate the process of entering ketosis.

5. Engage in physical activity 

Exercise can help deplete glycogen stores and promote the breakdown of fat for energy.

5 Ways to Enter Ketosis Faster 

While entering ketosis in a short time is not always possible for everyone, here are five strategies that may help:

High-intensity exercise

Engaging in high-intensity exercise can help deplete glycogen stores in the muscles, which can promote the breakdown of stored fat to provide energy for the body. This can help trigger the process of ketosis, where the body primarily uses fat for energy instead of glucose from carbohydrates.

Consume medium-chain triglycerides (MCTs) 

MCTs are a type of fat that is rapidly absorbed and metabolized by the body and can help increase ketone production. MCTs are broken down quickly by the liver into ketones, which can be used as an energy source by the body. This may help increase the level of ketones in the blood and promote the process of ketosis. MCTs can be found in coconut oil, palm kernel oil, and some dairy products and can also be taken as a supplement.

Intermittent fasting

When you fast, your body’s glycogen stores become depleted, which can trigger the production of ketones from stored fat to provide energy for the body. This may help kickstart the process of ketosis, where the body primarily uses fat for energy instead of glucose from carbohydrates. 

How long does it take to get into ketosis while fasting? Prolonged fasting or severe calorie restriction should only be done under the guidance of a healthcare professional, as it can have potential risks and side effects. 

Additionally, it’s vital that you’re still consuming adequate nutrients and fluids during fasting.

Reduce carbohydrate intake

Consuming fewer than 50 grams of carbohydrates daily can help you enter ketosis. When you limit your carbohydrate intake, your body’s glycogen stores become depleted which triggers the production of ketones from stored fat to provide energy for the body. In addition, by keeping carbohydrate intake low, the body is forced to primarily use fat for energy instead of glucose from carbohydrates, which promotes the process of ketosis. 

However, it’s important to note that everyone’s carbohydrate tolerance and ketone production are variable, and working with a healthcare professional such as a registered dietitian can help determine the right level of carbohydrate intake and monitor your health during the ketogenic diet.

Eating Keto But Not in Ketosis:  Potential Solutions

Eating Keto But Not in Ketosis:  Potential Solutions

While it’s ideal to be in ketosis while following a ketogenic diet, it’s still possible to experience some of the benefits even if you’re not in a state of ketosis. Here are some foods to focus on if you’re not in ketosis:

  • Healthy fats. Focusing on healthy fats like olive oil, avocados, nuts, nut butter, meat, eggs, fatty fish and seeds can help keep you feeling full and satisfied while also providing important nutrients.
  • Non-starchy vegetables. Vegetables such as spinach, broccoli, cauliflower, and kale are low in carbohydrates and provide a variety of vitamins and minerals.
  • Protein. It’s important to ensure that you get enough protein while following a ketogenic diet. Focus on lean sources of protein like chicken, fish, and tofu.
  • Lower-sugar fruits. Some fruits, like berries, are lower in carbohydrates and should be enjoyed while following a ketogenic diet.
  • Lower-carbohydrate dairy. Dairy products like cheese, butter, and heavy cream are high in fat and lower in carbohydrates and can be included in a ketogenic diet.

What Causes Low Ketones After Fasting and How to Address Them?

Low ketones after fasting can occur for a variety of reasons, including:

Insufficient calorie intake: Consuming too few calories during a fast can result in a decrease in ketone production.

Overconsumption of protein: Consuming too much protein can cause an increase in insulin levels, which can inhibit ketone production.

Dehydration: Dehydration can cause a decrease in ketone production.

Stress: Stress can cause an increase in cortisol levels, which can inhibit ketone production.

If you experience low ketones after fasting, there are several steps you can take to address the issue:

  • Increase calorie intake: Consuming more calories during a fast can help increase ketone production.
  • Limit protein intake: Limiting protein intake can help prevent an increase in insulin levels and promote ketone production.
  • Stay hydrated: Drinking plenty of water and electrolytes can help prevent dehydration and promote ketone production.
  • Reduce stress: Engaging in stress-reducing activities like meditation, yoga, or deep breathing exercises can help lower cortisol levels and promote ketone production.

Additionally, supplementing with electrolytes such as magnesium and sodium may be beneficial. Therefore, should you experience unexpected results during a fasted state, seeking appropriate interventions may help restore healthy ketone levels.


To summarize, ketosis is a biochemical process that typically takes anywhere from 2-4 days to initiate, depending on diet and activity levels. Once in ketosis, individuals may experience improved mental clarity, increased physical energy, appetite suppression, accelerated fat burning, and other potential health benefits.

Ketosis may not be suitable for everyone due to the potential side effects of bloodstream acidosis or ketoacidosis. However, those who are healthy may potentially benefit from positive outcomes seen with being in this type of metabolic state. 

For best results when attempting to reach ketosis, it is essential to define clear health and fitness goals ahead of time and seek reliable information from a qualified professional such as a registered dietitian or doctor.

With some patience and dedication to following an adequately developed nutrition and exercise strategy, it is possible to enter ketosis safely and benefit in the long term.

My name is Barbara Kovalenko. I hold a Bachelor's degree in Human Nutrition from Bogomolets National Medical University in Ukraine and a Master's degree from Boston University in the United States. Over the past few years, I have gained valuable experience as a nutritionist and have since decided to share my knowledge and expertise with a wider audience. Currently, I am working as a nutritional consultant with the Lasta app.

Weight Management Registered Dietitian, Health & Nutrition Writer, and Nutrition Consultant for Cardiometabolic Conditions. Renae is a Registered Dietitian with over 20 years of experience in the health and wellness industry. She counsels clients and develops nutrition plans addressing specific needs and goals. In addition, she is a health and nutrition writer and nutrition consultant for cardiometabolic conditions. A whole foods approach focusing on simplicity is her core nutrition philosophy. Renae graduated from the University of Michigan with a degree in Communications and completed the Didactic Program in Dietetics and Dietetic Internship at Loyola University Chicago.

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