Ask someone about how to get into ketosis and you’ll most likely hear the advice to cut carbs. While bringing down carbohydrates daily is a definitive way to enter ketosis — there are other ways to reach this metabolic state.
Here’s more about getting into ketosis using different strategies that are backed by research. But before that — a brief background on ketosis.
Ketosis, also called nutritional ketosis, is a normal metabolic state in which your body uses an alternate source of energy, called ketones, instead of glucose. It happens in response to low blood glucose, which is caused by carbohydrate deprivation.
Minimizing carbs leads to increased body fat breakdown. The resulting fatty acids are then metabolized to produce ketones, namely: acetoacetate, beta-hydroxybutyrate, and acetone. These ketones can be easily used to fuel your muscles, heart, kidneys, and brain (*).
Interestingly, ketosis produces more ATP (adenosine triphosphate, the energy-containing molecule) than when you’re running on glucose. Because of this, you’re able to carry out your activities even during a calorie deficit (*).
Some people choose to enter ketosis for different reasons, such as weight loss, mental clarity, more stable blood sugar, better endurance, and a lower risk of disease. If you plan on achieving ketosis for medical purposes, we recommend seeking guidance from a qualified health professional.
As you’ll learn, cutting carbs is just one of the many ways to speed up ketosis. Eating more fat and exercising are also part of making ketosis happen, among other things. Read the tips below:
1. Calculate your macros
The term “macros” is short for macronutrients, which are categories of nutrients that supply you with energy. These are carbs, protein, and fat. When it comes to reaching ketosis, the typical macro ratio to follow is 5-10% carbs, 55% to 60% fat, and 30% to 35% protein (*).
Tracking macros may sound complicated, but it can be as simple as entering your personal details — e.g. age, height, current weight, calorie intake — into a free keto macro calculator.
If you want to learn how to calculate macros manually to figure out how many grams you’ll need per macronutrient, follow these steps:
- Determine your daily calorie needs and macro percentages: For example, 1,500 calories for weight loss and 10% carbs, 60% fat, and 30% protein.
- Multiply your total calories by each macro percentage: Using the data above, you get 150 (for carbs), 900 (for fat), and 450 (for protein).
- Divide the calorie answers by the number of calories per gram for each macro: Since carbs have 4 calories per gram, fat has 9 calories per gram, and protein has 4 calories per gram, here are the actual number of grams you need — 38 grams of carbs, 100 grams of fat, and 113 grams of protein.
2. Cut down your carbohydrate intake
Keep in mind that ketosis happens when you don’t have enough carbs to produce glucose. When glucose is low, your body begins burning stored fat to create ketones, which now serve as your primary fuel source.
Note that while the degree of carb restriction depends on an individual — for instance, a person who’s very physically active can consume more carbs and still be in ketosis while someone who sits for hours daily with little physical activity will benefit from fewer carbs — the general carb limit for ketosis is 30-50 grams per day.
The easiest way for someone to stay under 50 grams of carbs is by filling up on animal-based foods, such as eggs, beef, pork, chicken, lamb, fish, seafood, and organ meats.
For vegetables, focus on non-starchy options like salad greens, cauliflower, broccoli, cucumbers, asparagus, and green beans. Fruits options are limited since most fruits are fairly high in carbs. In that case, fruits that are low-carb include avocados, berries, coconut meat, watermelon, and cantaloupe.
3. Increase your healthy fat intake
Dietary fat is an important component of the keto diet, which puts you in ketosis. Besides breaking down stored fat to produce ketones, your body also uses fats from your diet to help create them.
In the absence or lack of carbohydrates, more fat is needed for energy. Fat is calorie-dense, providing 9 calories per gram. It’s also slow to digest and won’t impact your blood glucose and insulin levels, unlike carbohydrates. Here are other important reasons to not fear fat:
- The presence of fat in a meal enhances vitamin absorption (*)
- Fat makes steroid hormones, such as estrogen, progesterone, and testosterone
- The right fats, such as omega-3s, improve brain function
When it comes to fat sources, it’s best to choose only healthy fats, such as those found in whole unprocessed foods. Examples are eggs, fatty cuts of meat (e.g. chicken thighs and pork belly), salmon, avocados, nuts, and seeds.
4. Increase your physical activity
Exercise can accelerate your transition into ketosis, especially with exercises that deplete your glycogen stores quickly. Examples of these activities include high-intensity interval training or HIIT for short (burpees, jump rope, mountain climbers), long runs lasting for 90 minutes, and other prolonged endurance exercises (*).
What would be even better is if you keep your carbohydrate intake low before a HIIT workout or a long run. Limiting your energy from carbs will improve your body’s fat-burning ability. Think of carbs as a crutch that hinders ketosis.
For people who are already practicing regular fasting and want to get physically active, exercising at the start of a fast also shortens the time it takes to enter ketosis. To make it easier for beginners, we recommend sticking to low-intensity exercises — those performed at a comfortable pace — such as walking, swimming, biking, and yoga. This will help with the adjustment process.
5. Incorporate intermittent fasting
Intermittent fasting (IF), which is an eating pattern where you cycle between having food and no food, has been known to induce ketosis. Studies show that IF regimens, such as alternate-day fasting (ADF), result in the depletion of stored glycogen and increased production of ketones (*).
You can start with a 12-hour fast — the shortest possible fasting duration — and combine it with exercise for the best results. Make sure to break your fast with low-carb foods, such as bone broth, leafy greens, eggs, and meat.
Alternatively, try a fat fast. Fat fasting can be a useful tool if you’re not yet ready to forgo food for many hours but still want to reap the ketone-boosting benefits of a regular fast. Basically, all you need to do is get the majority of your calories from high-fat foods. You can eat eggs (including egg yolks), salmon, and avocados.
6. Maintain adequate protein intake
Reducing carbs and increasing your fat aren’t the only methods for maintaining or entering ketosis. Protein needs to be adequate — around 30% to 35% of your total calories. Optimizing your protein intake helps stabilize your blood sugar, which curbs hunger, and other benefits like muscle preservation and recovery.
Keep in mind that everyone’s protein intake on keto varies. Those who need a higher protein intake while maintaining ketosis include older adults, bodybuilders or anyone looking to grow muscle, and people who are recovering from an injury.
7. Include MCT oil in your diet
Taking MCT oil, which stands for medium-chain triglycerides, can boost ketone production.
An article in Frontiers in Nutrition noted that MCTs provide a shortcut to ketosis. Furthermore, C8 (or caprylic acid) MCT oil has a higher ketogenic effect. It is three and six times more ketogenic than C10 and C12, respectively (*, *).
Besides supporting ketosis, MCT oil may improve exercise performance and gut and intestinal health (*).
If this is your first time taking MCT oil, we recommend starting slowly to reduce the likelihood of bloating and diarrhea. Perhaps begin with just one teaspoon for a few days. Gradually increase that to one tablespoon per day.
8. Test and monitor your ketone levels
Ketone testing is a helpful method to know whether you have reached ketosis or are still in ketosis. While paying attention to ketosis signs and symptoms can give you an idea of whether you’ve remained in this metabolic state, ketone testing offers objective data.
There are three ways to test your ketone levels, which check for the presence of the three types of ketones:
- Urine testing: This measures the ketone acetoacetate, which is excreted through the urine. In this case, urine ketone strips are used. When dipped into the urine, they change color, which correlates with specific ketone levels. The darker the color, the deeper a person is in ketosis.
- Blood testing: This measures the ketone beta-hydroxybutyrate, which is the most abundant ketone. Note that blood testing is by far the most accurate way to check for ketosis. It involves pricking your finger and taking a small blood sample, which will be analyzed by a small ketone meter. The optimal range for nutritional ketosis is 0.5–3.0 mmol/L (*).
- Breath testing: This measures the ketone acetone, which is exhaled through the lungs. Like urine testing, breath testing is non-invasive and convenient. It uses a portable breath acetone meter. Ketosis can produce breath acetone concentrations of 2–40 ppm (*).
Below are commonly asked questions about getting into ketosis:
How Long Does It Usually Take to Reach Ketosis?
Most healthy individuals experience ketosis in about 3-4 days of restricting carbohydrates or following a ketogenic diet. However, note that certain factors influence the time it takes to enter ketosis. This includes a person’s activity level, sleep, and stress.
You will know that you’ve entered ketosis because of keto flu symptoms, such as nausea, fatigue, and headaches. Moreover, watch out for increased ketone levels — as revealed through blood, breath, or urine ketone testing.
How long can I stay in ketosis?
However, it’s also important to note that many people on the keto diet intentionally go in and out of ketosis every week — an approach called a cyclical keto diet. Reasons to follow this include increasing your athletic performance and resetting your leptin levels (which ultimately lowers food intake).
For individuals who’ve been instructed to maintain ketosis by their healthcare provider to manage a medical condition, be sure to inform them of any changes.
Is it possible to get into ketosis within 24 hours?
Although it usually takes days for someone to reach ketosis, achieving it in 24 hours is also possible. To enter ketosis in the shortest possible time, you’ll need to do fasting, high-intensity exercises, and take exogenous ketones on top of reducing carbs to less than 50 grams.
Help your body utilize its fat stores and experience weight loss and better health through these tips. Remember that ketosis is a natural state where ketones replace glucose to fuel different organs. Testing using a blood ketone meter or urine strips will let you know that you’re already in ketosis.