During ketosis, your body converts fat into compounds known as ketones and begins using them as its main source of energy.
That being said, achieving a state of ketosis can take some work and planning. It's not just as simple as cutting carbs.
Here are 7 effective tips to get into ketosis.
Eating a very low-carb diet is by far the most important factor in achieving ketosis.
Normally, your cells use glucose, or sugar, as their main source of fuel. However, most of your cells can also use other fuel sources. This includes fatty acids, as well as ketones, which are also known as ketone bodies.
Your body stores glucose in your liver and muscles in the form of glycogen.
When carb intake is very low, glycogen stores are reduced and levels of the hormone insulin decline. This allows fatty acids to be released from fat stores in your body.
The level of carb restriction needed to induce ketosis is somewhat individualized. Some people need to limit net carbs (total carbs minus fiber) to 20 grams per day, while others can achieve ketosis while eating twice this amount or more.
For this reason, the Atkins diet specifies that carbs be restricted to 20 or fewer grams per day for two weeks to guarantee that ketosis is achieved.
After this point, small amounts of carbs can be added back to your diet very gradually, as long as ketosis is maintained.
In a one-week study, overweight people with type 2 diabetes who limited carb intake to 21 or fewer grams per day experienced daily urinary ketone excretion levels that were 27 times higher than their baseline levels (7).
In another study, adults with type 2 diabetes were allowed 20–50 grams of digestible carbs per day, depending on the number of grams that allowed them to maintain blood ketone levels within a target range of 0.5–3.0 mmol/L (8).
These carb and ketone ranges are advised for people who want to get into ketosis to promote weight loss, control blood sugar levels or reduce heart disease risk factors.
In contrast, therapeutic ketogenic diets used for epilepsy or as experimental cancer therapy often restrict carbs to fewer than 5% of calories or fewer than 15 grams per day to further drive up ketone levels (9, 10).
However, anyone using the diet for therapeutic purposes should only do so under the supervision of a medical professional.
Bottom Line: Limiting your carb intake to 20–50 net grams per day lowers blood sugar and insulin levels, leading to the release of stored fatty acids that your liver converts into ketones.
Eating coconut oil can help you get into ketosis.
It contains fats called medium-chain triglycerides (MCTs).
Unlike most fats, MCTs are rapidly absorbed and taken directly to the liver, where they can be used immediately for energy or converted into ketones.
In fact, it's been suggested that consuming coconut oil may be one of the best ways to increase ketone levels in people with Alzheimer's disease and other nervous system disorders (11).
Although coconut oil contains four types of MCTs, 50% of its fat comes from the kind known as lauric acid.
Some research suggests that fat sources with a higher percentage of lauric acid may produce a more sustained level of ketosis. This is because it's metabolized more gradually than other MCTs (12, 13).
MCTs have been used to induce ketosis in epileptic children without restricting carbs as drastically as the classic ketogenic diet.
In fact, several studies have found that a high-MCT diet containing 20% of calories from carbs produces effects similar to the classic ketogenic diet, which provides fewer than 5% of calories from carbs (14, 15, 16).
When adding coconut oil to your diet, it's a good idea to do so slowly to minimize digestive side effects like stomach cramping or diarrhea.
Start with one teaspoon per day and work up to two to three tablespoons daily over the course of a week.
Bottom Line: Consuming coconut oil provides your body with MCTs, which are quickly absorbed and converted into ketone bodies by your liver.
In addition, being more active can help you get into ketosis.
When you exercise, you deplete your body of its glycogen stores. Normally, these are replenished when you eat carbs, which are broken down into glucose and then converted to glycogen.
However, if carb intake is minimized, glycogen stores remain low. In response, your liver increases its production of ketones, which can be used as an alternate fuel source for your muscles.
One study found that at low blood ketone concentrations, exercise increases the rate at which ketones are produced. However, when blood ketones are already elevated, they do not rise with exercise and may actually decrease for a short period (21).
In a small study, nine older women exercised either before or after a meal. Their blood ketone levels were 137–314% higher when they exercised before a meal than when they exercised after a meal (23).
Keep in mind that although exercise increases ketone production, it may take one to four weeks for your body to adapt to using ketones and fatty acids as primary fuels. During this time, physical performance may be reduced temporarily (20).
Bottom Line Engaging in physical activity can increase ketone levels during carb restriction. This effect may be enhanced by working out in a fasted state.
Consuming plenty of healthy fat can boost your ketone levels and help you reach ketosis.
Indeed, a very low-carb ketogenic diet not only minimizes carbs, but is also high in fat.
Ketogenic diets for weight loss, metabolic health and exercise performance usually provide between 60–80% of calories from fat.
The classic ketogenic diet used for epilepsy is even higher in fat, with typically 85–90% of calories from fat (24).
However, extremely high fat intake doesn't necessarily translate into higher ketone levels.
A three-week study of 11 healthy people compared the effects of fasting with different amounts of fat intake on breath ketone levels.
Overall, ketone levels were found to be similar in people consuming 79% or 90% of calories from fat (25).
Furthermore, because fat makes up such a large percentage of a ketogenic diet, it's important to choose high-quality sources.
Good fats include olive oil, avocado oil, coconut oil, butter, lard and tallow. In addition, there are many healthy, high-fat foods that are also very low in carbs.
However, if your goal is weight loss, it's important to make sure you're not consuming too many calories in total, as this can cause your weight loss to stall.
Bottom Line: Consuming at least 60% of calories from fat will help boost your ketone levels. Choose a variety of healthy fats from both plant and animal sources.
Another way to get into ketosis is to go without eating for several hours.
In fact, many people go into mild ketosis between dinner and breakfast.
Moreover, "fat fasting" is another ketone-boosting approach that mimics the effects of fasting.
It involves consuming about 1,000 calories per day, 85–90% of which come from fat. This combination of low calorie and very high fat intake may help you achieve ketosis quickly.
A 1965 study reported significant fat loss in overweight patients who followed a fat fast. However, other researchers have pointed out that these results appear to have been highly exaggerated (30).
Because a fat fast is so low in protein and calories, it should be followed for a maximum of three to five days to prevent an excessive loss of muscle mass. It may also be difficult to adhere to for more than a couple of days.
Here are some tips and ideas for doing a fat fast to get into ketosis.
Bottom Line: Fasting, intermittent fasting and a "fat fast" can all help you get into ketosis relatively quickly.
Achieving ketosis requires a protein intake that is adequate but not excessive.
The classic ketogenic diet used in epilepsy patients is restricted in both carbs and protein to maximize ketone levels.
However, for most people, cutting back on protein to increase ketone production isn't a healthy practice.
First, it's important to consume enough protein to supply the liver with amino acids that can be used for gluconeogenesis, which translates to "making new glucose."
In this process, your liver provides glucose for the few cells and organs in your body that can't use ketones as fuel, such as your red blood cells and portions of the kidneys and brain.
Second, protein intake should be high enough to maintain muscle mass when carb intake is low, especially during weight loss.
Several studies have shown that the preservation of muscle mass and physical performance is maximized when protein intake is in the range of 0.55–0.77 grams per pound (1.2–1.7 grams per kilogram) of lean mass (20).
In one study of 17 obese men, following a ketogenic diet providing 30% of calories from protein for four weeks led to blood ketone levels of 1.52 mmol/L, on average. This is well within the 0.5–3.0 mmol/L range of nutritional ketosis (34).
To calculate your protein needs on a ketogenic diet, multiply your ideal body weight in pounds by 0.55 to 0.77 (1.2 to 1.7 in kilograms). For example, if your ideal body weight is 130 pounds (59 kg), your protein intake should be 71–100 grams.
Bottom Line Consuming too little protein can lead to muscle mass loss, whereas excessive protein intake may suppress ketone production.
Like many things in nutrition, achieving and maintaining a state of ketosis is highly individualized.
Therefore, it can be helpful to test your ketone levels to ensure you're achieving your goals.
The three types of ketones — acetone, beta-hydroxybutyrate and acetoacetate — can be measured in your breath, blood or urine.
The Ketonix meter measures acetone in breath. After breathing into the meter, a color flashes to indicate whether you are in ketosis and how high your levels are.
Ketones can also be measured with a blood ketone meter. Similar to the way a glucose meter works, a small drop of blood is placed on a strip that's inserted into the meter.
It measures the amount of beta-hydroxybutyrate in your blood, and it has also been found to be a valid indicator of ketosis levels (37).
The disadvantage of measuring blood ketones is that the strips are very expensive.
Lastly, the ketone measured in urine is acetoacetate. Ketone urine strips are dipped into urine and turn various shades of pink or purple depending on the level of ketones present. A darker color reflects higher ketone levels.
Ketone urine strips are easy to use and fairly inexpensive. Although their accuracy in long-term use has been questioned, they should initially provide confirmation that you are in ketosis.
A recent study found that urinary ketones tend to be highest in the early morning and after dinner on a ketogenic diet (38).
Using one or more of these methods to test ketones can help you determine whether you need to make any adjustments to get into ketosis.