Keto: When Does The Fat-Burning Begin?

The keto diet is a popular, effective way to lose weight and improve health. It involves drastically reducing your carbohydrate intake and replacing it with fat. This reduction in carbs puts your body into a metabolic state called ketosis, where it burns fat for energy instead of glucose. It usually takes 2-4 days to enter ketosis, but it can take longer depending on factors like physical activity level, age, metabolism, and carb, fat, and protein intake. During the transition to ketosis, it's common to experience flu-like symptoms, often referred to as the keto flu, which may include headaches, fatigue, nausea, and irritability.

The transition period

The first day on keto, the biggest struggle is usually figuring out your macro ratios and what it looks like to eat 75% fat. This is a big change for most people compared to the Standard American Diet. Keeping your protein low (around 15%) can also be tricky, especially if you are used to eating lean meats.

The second day is often when the "carb flu" starts, and this is typically the worst day. Your body is realising it is not getting carbs anymore, and the transition process to breaking down fats for fuel can be brutal. Be gentle with yourself during these days of your keto transition – there is no need to exercise if you’re feeling lethargic or nauseous. Try to keep activity to a minimum, and if you can, minimise how much work you have to do, too.

By the fourth day, you should start to feel better, and your body will be getting used to running off of fats for fuel. It is normal to continue feeling slight fatigue and malaise, so don’t be discouraged. Use your newfound energy to meal prep for the upcoming week, as preparation is your key to success during your first few days.

By the end of the first week, you will likely be hitting your stride. By now, you will understand what it looks and feels like to eat a diet that’s 70-75% fat and very low in carbohydrates. You may not have officially hit ketosis yet, but you’ll know if you’re close based on where your ketone levels read (thanks to your urine or blood tests). Some people can hit ketosis in their first week, but many do not. If you haven’t hit ketosis yet, don’t worry, it’s perfectly normal to still be transitioning.

The majority of people will hit ketosis by day 10, and you’ll likely be feeling pretty good by now. Your carb-flu symptoms will probably have gone, and you’ll be used to eating a high-fat diet. You might find your energy levels increasing, and you may not feel that hungry, having to remind yourself to eat.

What to eat and what to avoid

To enter ketosis, the metabolic state in which your body uses fat for fuel instead of carbohydrates, you need to drastically reduce your intake of carbohydrates and replace them with fat. This means limiting your consumption of grains or starches, sugary foods, fruit, beans or legumes, root vegetables and tubers, low-fat or diet products, condiments, unhealthy fats, and alcohol.

• Bread, pasta, rice, and other refined carbs
• Beer and mixed drinks
• Honey and syrups
• Fruit juice
• Soft drinks
• Ketchup, barbecue sauce, and other condiments
• Glazed or honey-baked ham
• Light or low-fat margarine
• Dried fruit or trail mix
• Low-fat diet foods
• Potatoes and other starchy vegetables
• Sweetened yogurt or dairy
• Certain fresh fruits, such as mangoes, bananas, and grapes
• Beans and other legumes
• Quinoa and other grains
• Milk and white chocolate

On the keto diet, you can eat meat, fish, seafood, eggs, vegetables, dairy products, natural fats, nuts, and berries. Here is a more detailed list of foods to eat:

• Meat, including beef, pork, lamb, wild game, and poultry
• Fatty fish, such as salmon, sardines, mackerel, and herring
• Mild white fish, such as cod, halibut, and trout
• Eggs
• Non-starchy vegetables, such as leafy greens, cucumber, celery, radishes, cauliflower, cabbage, avocado, broccoli, and zucchini
• Berries, lemons, and limes, in small servings
• Melons, in small servings
• Nuts and seeds, in small servings
• Cheese, butter, and cream
• Greek yogurt
• Avocados
• Olive oil
• Unsweetened coffee and tea
• Dark chocolate and cocoa powder, in small amounts

The benefits of ketosis

Ketosis is a metabolic state in which your body uses fat for fuel instead of carbohydrates. It occurs when you significantly reduce your consumption of carbohydrates, limiting your body’s supply of glucose (sugar), which is the main source of energy for the cells.

Weight Loss

Ketosis can lead to weight loss as the body starts burning fat for energy instead of carbohydrates. This can help reduce body fat and promote a leaner physique.

Improved Blood Sugar Management

Ketosis can help improve blood sugar levels, which is especially beneficial for people with type 2 diabetes or prediabetes. It may also reduce the need for blood sugar medications.

Reduced Seizures in Epilepsy

The ketogenic diet has been used to treat epilepsy, especially in children who don't respond well to drug treatments. It can significantly reduce seizures and sometimes even lead to remission.

Improved Brain Function

Ketosis may increase focus and energy levels, and some research suggests that it could improve outcomes for traumatic brain injuries.

Lower Risk of Heart Disease

The keto diet has been associated with a reduced risk of heart disease. It can lower blood pressure, increase "good" HDL cholesterol, and decrease triglyceride levels, all of which are beneficial for heart health.

Reduced Metabolic Syndrome Symptoms

Ketosis can effectively treat all five key symptoms of metabolic syndrome, which is a condition that increases the risk of heart disease and type 2 diabetes.

Other Potential Benefits

The keto diet is also being studied for its potential benefits in treating Alzheimer's disease, Parkinson's disease, cancer, polycystic ovary syndrome, and other neurological conditions.

While ketosis has many potential benefits, it's important to note that it may also come with certain side effects and is not suitable for everyone. It is always recommended to consult a healthcare professional before starting any new diet, especially one as restrictive as the keto diet.

Side effects of the keto diet

The keto diet is a low-carb, high-fat diet that has been associated with several health benefits, including weight loss, increased energy, and the treatment of chronic illnesses. However, there are also some potential side effects to be aware of.

One of the most well-known side effects of the keto diet is the "keto flu," which includes symptoms such as headaches, dizziness, fatigue, nausea, and constipation. These symptoms are often due to dehydration and electrolyte imbalances as the body adjusts to using ketones and fats as its primary energy source. While most people experience relief within a few weeks, it is important to monitor these symptoms and stay hydrated.

The keto diet may also increase the risk of kidney stones. High-fat animal foods, such as eggs, meat, and cheese, are staples of the keto diet and can make the blood and urine more acidic. This can lead to an increased excretion of calcium in the urine and a higher risk of kidney stone formation.

Additionally, the keto diet can cause digestive issues and changes in gut bacteria. The restriction of carbohydrates can make it challenging to meet daily fiber needs, leading to digestive discomfort and constipation. A lack of fiber can also negatively impact the beneficial bacteria in the gut, potentially affecting immunity, mental health, and inflammation.

The keto diet may also lead to nutrient deficiencies over time. By restricting nutrient-dense fruits, whole grains, and legumes, the diet may not provide sufficient amounts of vitamins and minerals such as calcium, vitamin D, magnesium, and phosphorus.

Furthermore, the keto diet has been linked to dangerously low blood sugar levels, especially in individuals with type 1 diabetes. This can increase the risk of hypoglycemia, which is marked by symptoms such as confusion, shakiness, fatigue, and sweating. Left untreated, hypoglycemia can lead to coma and death.

The keto diet has also been associated with impaired bone health. Several studies have linked the diet to decreased bone strength and reduced bone mineral density.

Lastly, the long-term effects of the keto diet on the risk of chronic diseases and early death are still being studied. Some evidence suggests that high-fat, low-carb diets focusing on animal foods may lead to poor health outcomes, while diets emphasizing vegetable sources of fats and proteins may provide benefits.

While the keto diet has gained popularity for its potential health benefits, it is important to be aware of these potential side effects. Individuals with kidney disease, diabetes, heart or bone ailments, or other medical conditions should consult their healthcare provider before starting the keto diet.

How to get into ketosis faster

Ketosis is a metabolic state in which your body uses fat for fuel instead of carbohydrates. Ketosis is achieved by restricting your intake of carbohydrates, moderating protein consumption, and increasing calories obtained from fat.

Generally, it takes 2-4 days to enter ketosis if you eat 20-50 grams of carbohydrates per day. However, some people may take longer depending on factors like physical activity level, age, metabolism, and carbohydrate, fat, and protein intake.

Tips to Get into Ketosis Faster:

• Reduce your carbohydrate intake: By drastically reducing your carb intake to under 50 grams per day, your body is forced to use up its glycogen stores for energy and eventually switch to using ketones as fuel.
• Increase your fat intake: Aim to get at least 55-60% of your calories from healthy fats such as nuts, nut butter, extra virgin olive oil, avocado oil, avocados, meats, eggs, and fatty fish like salmon.
• Moderate your protein intake: Protein can be converted into glucose if consumed in high amounts, which may slow down your transition into ketosis.
• Try intermittent fasting: Fasts like intermittent fasting may help your body shift its fuel source from carbs to fat while maintaining its energy balance.
• Exercise more: Physical activity can deplete your body's glycogen stores, encouraging your liver to increase its production of ketones. Studies show that working out in a fasted state can help increase ketone levels.
• Reduce stress: Cortisol, released during periods of stress, allows glycogen (stored carbohydrates in your muscles) to get released into the bloodstream, triggering a blood glucose spike that inhibits ketogenesis.
• Test your ketone levels regularly: Testing ketone levels can help give you an idea of whether you're in ketosis, allowing you to adjust your diet and exercise routine accordingly.

Frequently asked questions