Entering Ketosis: How Many Days Does It Take?

Ketosis is a metabolic state in which the body primarily burns stored fat instead of glucose for fuel. This natural metabolic state is achieved when the body is deprived of carbohydrates, its main fuel source. The presence of ketones in the blood and urine indicates that a person has entered ketosis. The time taken to enter ketosis varies from person to person and can depend on factors such as metabolism, physical activity levels, age, body composition, sleep habits, and stress levels. For most people, it takes a few days to enter ketosis, but for some, it may take a week or longer.

Fasting for 24-48 hours

Fasting for this duration is not suitable for everyone. It is always recommended to consult a doctor or medical professional before beginning a fast, especially if you are taking medication or have an underlying medical condition. Those with type 1 diabetes, low blood pressure, or a history of eating disorders should be extra cautious. Additionally, pregnant, breastfeeding, or nursing women are advised to avoid this type of fast.

If you are new to intermittent fasting, it is best to start with shorter fasts of 12-18 hours and gradually work your way up to longer ones. This allows your body and mind to adjust to the practice.

During a 24-48 hour fast, your body will transition from burning sugar for energy to burning stored fat. This process can lead to weight loss and improved blood sugar control. Fasting for longer periods also gives your body more time for cellular cleaning and repair through autophagy, which can provide anti-aging benefits and prevent disease.

However, there are some downsides to fasting for 24-48 hours. The longer the fast, the greater the potential for side effects such as hunger, dizziness, sluggishness, and exhaustion. It is important to listen to your body and stop the fast if you feel unwell.

To break a 24-48 hour fast, start by eating a light snack such as a handful of nuts, followed by a small meal after an hour or two. It is important to gradually reintroduce food to avoid overstimulating your gut, which can lead to bloating, nausea, and diarrhea.

Some people may choose to incorporate 24-48 hour fasts into their intermittent fasting routine a few times a month to boost weight loss and other health benefits.

Reducing carb intake

Reducing your carbohydrate intake is essential to entering ketosis, a metabolic state in which your body uses ketones for energy instead of glucose. To reach this state, you must deplete your glucose levels. Typically, this means limiting your carb consumption to 50 grams or less per day, though the exact limit depends on the individual.

The transition to ketosis can be challenging, and the time it takes varies from person to person. It usually takes a few days, but it can take a week or longer. The time it takes depends on factors such as your biology, diet, exercise habits, genetics, and more. For example, an athlete may enter ketosis faster than someone with type 2 diabetes.

• Gradual transition: While it is possible to reach ketosis in 24 hours through fasting and exercise, this is not recommended due to the discomfort involved. A gradual transition through a standard ketogenic diet is a more sustainable approach.
• Limit carbs: Keep your carb intake below 10% of your daily calories. Be aware that carbs can be hidden in soups, sauces, fruits, starchy vegetables, and even mussels. Track your carb intake using an app or food journal.
• Intermittent fasting: This involves taking regular breaks from calories, helping to keep insulin levels low. It can be combined with the keto diet to accelerate fat adaptation. However, listen to your body, and consult a doctor if you are elderly or have a medical condition.
• Exercise: Physical activity helps deplete glycogen stores and primes your body to start making ketones. High-intensity cardio or resistance training, such as running, kickboxing, biking, or HIIT, are ideal.
• Increase healthy fats: Most people on the ketogenic diet replace lost carbs with healthy fats. Good sources include avocados, avocado oil, fatty fish like salmon, olive oil, butter, ghee, and fatty cuts of meat. However, limit saturated and trans fats from fried foods.
• Test ketone levels: Use blood ketone meters or urine strips to measure your ketone levels. Blood ketones are the gold standard, with levels of 0.5 mmol/L to 3.0 mmol/L indicating nutritional ketosis.
• Manage protein intake: On the keto diet, you typically eat more fat than protein. A standard recommendation is to consume about 1 gram of protein per pound of body weight per day. However, some believe lower protein intake is necessary.

Increasing physical activity

Exercise can play a crucial role in helping you reach ketosis faster. The more energy you use, the more fuel your body needs, and exercise helps deplete the body's glycogen stores (glycogen is a form of glucose). Typically, eating carbs restores glycogen levels, but on a low-carb ketogenic diet, you're not sufficiently replenishing these stores, which encourages your body to turn to fat as a source of fuel instead.

High-intensity exercises such as running, kickboxing, biking, or high-intensity interval training (HIIT) can help you rapidly deplete your glycogen stores and prime your body to start making ketones. HIIT, in particular, depletes glycogen stores faster and can speed up the adaptation phase.

Research also shows that prolonged exercise and endurance sports like jogging, swimming, and cycling support a ketotic state and push your body to use fat for fuel. Additionally, studies indicate that exercise and resistance training on a keto diet increase fat burning and boost muscle strength.

It's important to note that you should always listen to your body and not over-exert yourself. If you're experiencing symptoms like fatigue and weakness, you may be going through the "`keto flu." However, exercising through it can help alleviate these symptoms. Staying hydrated and supplementing with electrolytes can also help you manage the transition to ketosis.

By increasing your physical activity, you can accelerate the process of reaching ketosis and take advantage of the additional health benefits that exercise brings.

Increasing healthy fat intake

Achieving ketosis typically takes a few days, but it can take longer for some people. To enter ketosis, you need to cut down on carbohydrates and increase your intake of healthy fats. Here are some tips to increase your healthy fat intake:

• Avocados and avocado oil: Avocados are incredibly versatile and can be added to sandwiches, wraps, smoothies, and Mexican dishes like guacamole. Avocado oil is great for roasting vegetables.
• Fatty fish: Salmon, tuna, mackerel, sardines, and anchovies are excellent sources of healthy fats.
• Plant-based oils: Use olive oil, avocado oil, and walnut oil for cooking, roasting, and salad dressings.
• Nuts and seeds: These are great for snacking and can be added to salads, smoothies, and vegetable dishes. Try almonds, hazelnuts, pistachios, pecans, pumpkin seeds, sunflower seeds, and sesame seeds.
• Dairy products: Cream, full-fat milk, and cheeses are good sources of saturated fat.
• Meats: Fatty cuts of meat, such as chicken thighs and pork belly, are recommended. Red meats like beef, lamb, and pork are high in saturated fat but should be consumed in moderation.
• Coconut products: Coconut oil, coconut cream, and coconut flakes are examples of coconut products that are rich in saturated fat.
• Bulletproof coffee: Start your day with a cup of bulletproof coffee, which is a mixture of brewed coffee, grass-fed butter, and MCT oil.
• Creamy soups and sauces: Full-fat dairy products like cream and cheese can be used to make creamy soups and sauces.
• Fat bombs: Make keto fat bombs, which are bite-sized treats with high-fat ingredients like cream cheese, nut butter, and coconut oil.
• Full-fat dairy smoothies: Combine full-fat dairy products like heavy cream, full-fat yogurt, and whole milk with other keto-friendly ingredients like nut butter and low-carb fruits.

Testing ketone levels

There are two other ways to test your ketone levels: urine testing and breath testing. Urine testing involves dipping test strips into a urine sample, which will change colour according to the levels of ketones. The darker the colour, the deeper the state of ketosis. Breath testing uses a portable breath-acetone meter to measure acetone, a type of ketone, that is exhaled through the lungs. Ketosis can produce breath acetone concentrations of 2–40 ppm.

While blood testing is the most accurate method, subjective measures can also indicate whether you're in ketosis. For example, you might be losing fat, craving fewer snacks, or not feeling hungry.

Frequently asked questions