How to Convince Your Body to Start Burning Fat: 5 Tried-and-Tested Strategies for Entering Ketosis

Imagine your body quietly switching fuel tanks – leaving sugar behind and turning to its own fat reserves for energy. That switch is real, it has a name, and it is called ketosis. It is not just a fashionable diet – it is a metabolic process that researchers have been studying for more than a century, and it is linked to appetite control, weight management, blood sugar balance and even brain health. Here are the key steps that may help you get there.

A Hollywood star who has followed keto for decades

Few people have been as open about this way of eating as Oscar-winning actress Halle Berry. She has explained publicly that she was diagnosed with diabetes in her early twenties and that food has played a central role in her life ever since. She has said she has followed a ketogenic lifestyle for many years to help manage her condition, and she has even shared keto resources with her Instagram followers. In an interview with Women's Health, she described her typical morning starting with coffee blended with butter, MCT oil and collagen – an idea that connects neatly with the coconut oil tip later in this article.

It is worth adding some balance: some of Berry's past statements about "reversing" diabetes drew strong criticism from the diabetes community, because type 1 diabetes cannot be cured with diet. Her story is a reminder that ketosis can be a meaningful tool for some people, but it is not a miracle cure and should never replace medical treatment.

Researchers have found that an eating pattern that encourages ketosis can be very beneficial for many people, because it may help curb appetite and support weight loss. A review by the Harvard T.H. Chan School of Public Health notes that participants on very low-carbohydrate diets reported less hunger despite significant restrictions. Ketosis is also being studied in connection with diabetes, neurological disorders and a range of other conditions. However, researchers have also found that simply cutting out carbohydrates is not always enough to reach ketosis.

So how can you encourage your body to turn fat into energy more efficiently?

1. Reduce your carbohydrate intake

Eating low-carbohydrate foods is essential for reaching ketosis, because cells use sugar – or glucose – as their main source of energy. However, cells can also use other fuel sources, such as fatty acids and ketones, which are known as ketone bodies.

Glucose is stored as glycogen in the liver and muscles. When carbohydrate intake is low, these stores shrink, insulin levels fall, and fatty acids are released from fat reserves. The liver converts some of these fatty acids into ketone bodies, which can, among other things, serve as fuel for the brain. If you would like to understand why carbohydrates are not "the enemy" in a normal diet, read our article The Role of Carbohydrates in a Healthy Diet.

To support ketosis, many nutritionists suggest limiting carbohydrates to around 20 grams of net carbs (total carbohydrates minus fiber) during the first two weeks, and only then gradually increasing the amount. This approach mirrors a study published in the Journal of the American Dietetic Association, in which overweight women ate no more than 20 grams of carbohydrates a day for two weeks and then added 5 grams per week. Ketone levels in their blood were highest in the first week and remained above baseline throughout the study.

Tests have shown that on such a strict regimen, ketone levels can rise considerably – some reports describe urinary ketone levels increasing many times over. A more recent study published via PubMed Central found that when participants reduced net carbohydrates to roughly 27 grams a day, measurable nutritional ketosis appeared within about a week – and the fewer carbohydrates they ate, the higher their ketone levels tended to be.

A strict plan like this is often chosen by people who want to enter ketosis to manage their weight, improve certain heart health markers and support steadier blood sugar. Keep in mind that the first kilograms often come off quickly – but much of that is water, not fat. We explain why in The dilemma of all diets: have you really lost weight or have you just lost excess water?

There are also therapeutic ketogenic diets used under close medical supervision. According to UC Davis Health, the ketogenic diet was first used in the 1920s to help children with drug-resistant epilepsy, and it is still used today when medication alone is not enough. Such clinical diets can be even stricter – sometimes under 15 grams of carbohydrates a day – which raises ketone levels further. Researchers are also exploring ketogenic approaches in other areas, including certain cancers, but this research is still at an early stage and such diets should only ever be followed as part of a medical team's plan.

As a general rule, ketosis tends to begin when carbohydrates make up only a small share of your daily energy intake over a longer period. Popular ketogenic guidelines summarized by Harvard's Nutrition Source suggest roughly 5–10% of calories from carbohydrates, 70–80% from fat and 10–20% from protein.

A reader shared her experience with us: "The first three days were tough – I had a mild headache and felt sluggish. My nutritionist explained that this is common while the body adjusts and told me to drink more water and add a pinch of salt to my soup. By the end of the first week, I noticed I simply wasn't thinking about snacks anymore."

2. Increase your intake of healthy fats

Eating healthy fats can increase ketone levels and help you reach ketosis. A low-carbohydrate ketogenic diet is naturally high in fat. However, this does not mean that every high-fat food will lead to ketosis – or that every high-fat food is a good choice.

Because fats make up such a large percentage of a ketogenic diet, it is important to choose high-quality sources, such as avocado and avocado oil, coconut oil, butter, and extra virgin olive oil. Nuts, seeds and oily fish such as salmon and mackerel are also excellent additions.

If your goal is weight loss, remember that calories still count. Fat contains more than twice as many calories per gram as carbohydrates, so even on a ketogenic diet you should not eat more energy than your body needs. As a WeightWatchers article explains, the main advantage of fat and protein is that they promote a feeling of fullness, which makes it easier to eat less. Be careful, too, with processed "diet" products – some of them quietly undo your efforts, as described in Hello, and Fattening: Foods that Sabotage Your Diet.

3. Include coconut oil

Adding coconut oil to your diet may help you enter ketosis. It is rich in medium-chain fatty acids, which the liver can quickly convert into ketones. Concentrated MCT oil, made from these fatty acids, has been studied in people with Alzheimer's disease and other disorders of the nervous system. In a randomized, placebo-controlled study published in Alzheimer's & Dementia: Translational Research & Clinical Interventions, most participants who took MCT oil regularly remained cognitively stable or improved. A systematic review of 21 studies also observed a substantial rise in ketone levels with MCT use. These findings are promising, but the evidence is still limited, and MCT oil is not a treatment for dementia.

A tip before you start: add coconut oil to your diet gradually to avoid diarrhea and stomach cramps. Start with one teaspoon a day and slowly work up to 2 to 3 tablespoons; after a week, you can adjust the amount to suit you. Since coconut oil is high in saturated fat, many health authorities recommend moderate use, so think of it as one of several fats in your kitchen rather than the only one.

Herbs and spices can also make low-carb meals more interesting and support digestion – see our selection in 5 best herbs for burning fat.

4. Eat the right amount of protein

It has been shown that drastically cutting protein to boost ketone production is not a healthy strategy. The liver needs protein to obtain amino acids, which are used to produce new glucose for the organs and cells that cannot run on ketones. Protein is also essential for maintaining muscle mass, which is especially important during weight loss.

On the other hand, very large amounts of protein can slow the transition into ketosis, because the body can convert excess amino acids into glucose. That is why Harvard's Nutrition Source describes protein on a ketogenic diet as moderate: enough to preserve lean body mass, but not so much that it prevents ketosis. For a 2,000-calorie diet, that works out to around 75 grams of protein a day. Good sources include eggs, fish, poultry, meat, cheese and Greek yogurt.

5. Stay physically active

Exercise depletes glycogen stores, which helps the body reach ketosis. Keep in mind that the body needs anywhere from 1 to 4 weeks to adapt to using ketones as its main fuel, and during this time it helps to stay moderately active – brisk walks, cycling, swimming or light strength training are all good choices. In the first days, your performance may temporarily dip; this usually improves once your body adapts.

Ketone production is highest during fasting, which is why some people combine a ketogenic diet with shorter periods of time-restricted eating. This may support weight management, but longer fasts are not suitable for everyone – especially people with diabetes, pregnant or breastfeeding women, and anyone with a history of eating problems. Rest matters too: poor sleep can work against your efforts, as we explain in When you sleep too little, your belly grows.

Another reader told us: "I started walking for 40 minutes every morning before breakfast. The first two weeks felt heavy, but after that I had more steady energy than ever – no more afternoon slump after lunch."

Before you begin: a few words of caution

A ketogenic diet is quite restrictive, and it can be difficult to get enough vitamins, minerals and fiber if you do not eat plenty of low-carbohydrate vegetables such as spinach, kale, broccoli and zucchini. As experts quoted by WeightWatchers point out, people with diabetes – particularly those taking medication – should only try a ketogenic diet in consultation with their doctor, because medication doses may need adjusting. The same applies to anyone with kidney, liver or heart conditions.

Ketosis is not magic, but for many people it can be a useful way to rethink how they eat, calm cravings and take better care of their health. The key is to approach it thoughtfully, listen to your body, and choose quality food over quick fixes.