Keto Adaptation: Carb Tolerance Explained

The keto diet is based on the principle that the body can burn fat instead of carbohydrates for energy. The goal of this diet is to achieve ketosis, a state in which the body and brain burn fat as their main source of energy. Fat-adapted is a term used to describe someone whose body has reached a state in which it more effectively burns fat for energy.

Fat adaptation is a long-term metabolic transition to burning fat instead of carbs. It is thought to be a more stable and efficient state than the initial state of ketosis. However, it is important to note that fat adaptation is not the same as ketosis. Ketosis is the production of ketones, which can happen overnight, while fat adaptation takes a month or more.

To enter ketosis, one must restrict their carb intake to no more than 50 grams per day for several days. This can be challenging and may cause symptoms such as fatigue, brain fog, and bad breath, commonly known as the keto flu.

So, does being keto-adapted mean you can eat carbs? The answer is not exactly. While those who are keto-adapted may have more flexibility in their diet, it is important to maintain a low-carb, high-fat diet to stay in ketosis and reap the benefits of the keto diet, such as increased energy and weight loss.

Stable energy levels throughout the day

On a high-carb diet, the body breaks down carbohydrates into glucose, which is then absorbed into the bloodstream with the help of insulin. Insulin helps transport glucose from the bloodstream to the cells, where it is used for energy. However, this process can lead to an energy rollercoaster, with spikes and crashes in blood sugar levels, leaving you feeling tired and sluggish.

On the other hand, the keto diet promotes stable energy levels by utilising fat stores instead of carbohydrates for energy. Instead of relying on frequent carb refuelling, the body can tap into its fat stores whenever it needs energy. This results in a constant, steady stream of energy, without the drastic dips caused by fluctuating blood sugar levels.

The transition to a keto diet can be challenging and may cause symptoms such as stomach aches, nausea, and brain fog, commonly known as the "keto flu". However, once the body adapts to using fat for energy, many people report improved energy levels and a reduction in afternoon energy slumps.

Additionally, the keto diet may also decrease cravings and hunger, as the body becomes more efficient at burning fat for fuel. This can lead to better appetite control and sustained energy levels throughout the day.

Less fatigue

The keto diet is a very-low-carb, high-fat diet that causes weight loss and provides numerous health benefits. However, it is common to experience fatigue when starting out on the keto diet. This is often due to the body adjusting to using fat as its main energy source, rather than carbohydrates. This adjustment period is known as keto adaptation, and it usually lasts for the first week of the keto diet. During this time, you may experience fatigue, headaches, and other minor side effects.

Causes of Fatigue on Keto

There are several reasons why you may feel fatigued when starting the keto diet. Here are some of the most common causes and how to address them:

• Keto flu: This is a common side effect when starting the keto diet, as your body adjusts to using fat as its main energy source. Make sure to stay well-hydrated and consider taking an electrolyte supplement to help alleviate symptoms.
• Dehydration: On a low-carb diet, your body excretes more water and electrolytes. Drink plenty of water and consider taking an electrolyte supplement to prevent dehydration, which can lead to fatigue, brain fog, and muscle cramps.
• Undereating: The keto diet suppresses appetite, which can lead to unintentional undereating. This can reduce your body's production of energy hormones, leading to fatigue. Make sure to eat enough calories and healthy fats to support your energy levels.
• Exercise: If you are following a rigorous workout plan, you may need to introduce carbs back into your diet in a targeted way. Consider using targeted keto or cyclical keto approaches to provide energy for physical activity.
• Dirty keto: Eating processed foods that fit keto macros but are not nutritious can lead to nutrient deficiencies and worsen fatigue. Prioritize fresh vegetables, high-quality protein, and healthy fats instead.
• Carb intake: If you are not in ketosis, increasing your carb intake from keto-friendly fruits and vegetables may help address fatigue.
• Macros: Ensure you are consuming the right balance of fats, protein, and carbs. Use a keto macro calculator to determine the best macros for your goals and track your intake with an app.
• Inactivity: A sedentary lifestyle can contribute to fatigue. Incorporate regular exercise or brisk daily walks to increase your energy levels.

Supplements for Fatigue on Keto

• MCT oil powder: This can help increase ketone production and reduce symptoms of keto flu, such as brain fog.
• BHB exogenous ketones: These provide immediate mental and physical energy.
• Keto electrolytes: If you exercise frequently or live in a hot climate, consider taking keto electrolytes to prevent dehydration and associated fatigue.
• Keto whey protein powder: Boost your protein intake, especially after a workout, to support energy levels.
• Perfect Keto Pills: If you have insulin resistance, these pills can help manage blood sugar and improve energy levels.

Less frequent meals

The ketogenic diet is a high-fat, low-carb diet that can be challenging to maintain. It is important to monitor your intake of carbohydrates, proteins, and fats to stay within the desired ranges.

The keto diet recommends that 70-80% of your calorie intake should come from fats, 10-20% from protein, and 5-10% from carbohydrates. This means that your meals and snacks should consist of foods like meats, fats, oils, and non-starchy or low-carb vegetables.

If you are following a keto diet and choosing to eat less frequently, it is important to ensure that you are still meeting your calorie and nutrient requirements. Here are some tips and guidelines to help you incorporate less frequent meals into your keto diet:

• Plan your meals: Determine the number of meals you will be eating and plan them accordingly. Since your calorie intake will be concentrated in fewer meals, make sure each meal contains sufficient calories and nutrients.
• Focus on nutrient-dense foods: To meet your nutritional needs, prioritize nutrient-dense foods that are high in healthy fats and low in carbs. Examples include fatty fish like salmon, eggs, avocados, nuts, seeds, and non-starchy vegetables like spinach, broccoli, and peppers.
• Include moderate protein: While the keto diet is primarily focused on fat intake, ensure that you are still including moderate amounts of protein in your less frequent meals. Examples of protein sources include meat, poultry, and dairy products like cheese and Greek yogurt.
• Be mindful of portion sizes: With less frequent meals, you may be tempted to consume larger portions. Remember that keto is not just about reducing carbs but also about achieving the right balance of fats and proteins. Monitor your portion sizes to ensure you are staying within the desired macronutrient ratios.
• Consider intermittent fasting: If you are reducing the number of meals you eat per day, you may be incorporating longer fasting periods into your routine. Intermittent fasting can have potential benefits, but it is important to speak with a healthcare professional before starting any new dietary practice.
• Monitor your hunger levels: Less frequent meals may lead to increased hunger between meals. If you find yourself getting too hungry, consider adding an additional meal or adjusting the timing of your meals.
• Stay hydrated: Drinking plenty of water is always important, but it is especially crucial when following a keto diet. Water can help you feel more full and may also aid in weight loss.
• Speak with a healthcare professional: Before making any significant dietary changes, it is always advisable to consult with a doctor or registered dietitian. They can help you determine if less frequent meals are suitable for your specific needs and ensure that you are meeting your nutritional requirements.

Incorporating less frequent meals into a keto diet can be done safely and effectively by following these guidelines. Remember to listen to your body and adjust your meal frequency and timing as needed to maintain optimal health and well-being.

More endurance during physical activity

The ketogenic diet has become popular among endurance athletes as a performance enhancer. The diet prescribes a significant reduction in carbohydrate intake, which facilitates physiological changes that promote the utilization of ketones. The body can reserve large amounts of energy in the form of fat. One pound of fat yields approximately 3500 kcal, making fat a vast source of energy, even among relatively lean endurance athletes. In theory, if endurance athletes tolerate the ketogenic diet, they could achieve longer training periods with sustained energy levels and reduced need for refueling, allowing them to maximize the aerobic benefits from training and competing.

The ketogenic diet is based on the principle that the body can burn fat instead of carbs (glucose) for energy. After a few days, a diet very low in carbs and high in fat puts your body in ketosis, a state in which it breaks down fatty acids to form ketone bodies for energy. "Fat-adapted" means that your body has reached a state in which it more effectively burns fat for energy.

Keto-adaptation may provide a consistent and fast energy supply, thus improving exercise performance and capacity. With its anti-inflammatory and anti-oxidative properties, a ketogenic diet may contribute to muscle health, thus preventing exercise-induced fatigue and damage. A ketogenic diet involves using fat, a high-density substrate, as the main source in daily calorie intake while restricting carbohydrate intake. In this way, the liver is forced to produce and release ketone bodies into the circulation. This phenomenon is called nutritional ketosis. Over time, the body will acclimate to using ketone bodies as a primary fuel, which is called keto-adaptation, an element of fat-adaptation.

Glucose oxidation requires 11 steps to produce energy, whereas fat and ketone bodies can quickly provide energy in only three steps. In any case, the capacity for the body to reserve ketone bodies and fat is much stronger. Compared to glucose, ketone bodies are more energy-intensive, while a ketone body-centered metabolism has the potential to provide a consistent, fast energy supply.

A study by Volek et al. (2018) examined the effects of consuming a 12-week low-carbohydrate ketogenic diet (LCKD) versus a high-carbohydrate diet (HC), while incorporating a training intervention, on exercise performance and body composition. The LCKD group experienced a significantly greater decrease in body mass and percentage body fat. Fasting serum beta-hydroxybutyrate (βHB) significantly increased from 0.1 at baseline to 0.5 mmol/L in the LCKD group in week 12. There was no significant change in performance of the 100 km time trial between groups. SS sprint peak power increased by 0.8 watts per kilogram bodyweight (w/kg) in the LCKD group, versus a − 0.1 w/kg reduction in the HC group. CPT peak power decreased by − 0.7 w/kg in the HC group, and increased by 1.4 w/kg in the LCKD group. Fat oxidation in the LCKD group was significantly greater throughout the 100 km time trial.

In a study by Ma et al. (2018), an 8-week ketogenic low-carbohydrate, high-fat diet enhanced exhaustive exercise capacity in mice. The diet enhanced fatigue recovery, post-exercise biomarkers, and anti-oxidation capacity. In another study by Ma et al. (2018), a ketogenic diet alternated interleukin-6, ketolytic and lipolytic gene expression, and enhanced exercise capacity in mice.

In a study by Zinn et al. (2017), a ketogenic diet benefited body composition and well-being but not performance in a pilot case study of New Zealand endurance athletes. The diet did not enhance endurance capacity.

In a study by Burke et al. (2017), a low-carbohydrate, high-fat diet impaired exercise economy and negated the performance benefit from intensified training in a group of elite race walkers.

In a study by McSwiney et al. (2018), keto-adaptation enhanced exercise performance and body composition responses to training in endurance athletes.

Fewer cravings

The keto diet is a very low-carb, high-fat diet that can provide health benefits such as increased energy, weight loss, improved mental function, and blood sugar control. The goal of this diet is to reach a state called ketosis, where the body and brain burn fat as their main source of energy.

Keto-adaptation occurs when the body is restricted to a very low number of carbs, which induces a sustained nutritional ketosis state. In this state, the body becomes more efficient at burning fat for energy instead of carbohydrates. This can lead to a reduction in cravings, as the body becomes less reliant on sugar and carbohydrates.

Benefits of Keto-Adaptation

One of the benefits of keto-adaptation is a reduction in cravings, especially sugar cravings. This is because the body is no longer relying on sugar for energy and has transitioned to using fat as its primary fuel source. Additionally, keto-adaptation can lead to increased energy levels and improved mental focus.

Tips for Reducing Cravings

• Mindful eating: Pay attention to your hunger cues and stop eating when you're full. Try to eat most of your meals at home without distractions.
• Keep triggers out of sight: If you can't resist desserts or other trigger foods, don't keep them in the house.
• Eat low-carb vegetables: Include non-starchy vegetables like kale, spinach, broccoli, and asparagus in your meals. These are nutrient-dense and provide indigestible carbohydrates that won't kick you out of ketosis.
• Get enough sleep: Sleep deprivation can increase cravings, so aim for 7-9 hours of sleep per night.
• Stay hydrated: Drink plenty of water and electrolytes to meet your increased fluid needs on a keto diet.
• Don't restrict calories: Instead of restricting calories, focus on eating a well-rounded diet with appropriate macros and indulging in treats occasionally.
• Give it time: Keto-adaptation can take a few weeks, so be patient and stick to the diet.
• Balance blood sugar: Consume balanced meals of high-quality protein, healthy fats, and low-carb veggies to maintain healthy blood sugar levels.
• Consume healthy fats: Dietary fat is crucial for satiety and can prevent overeating. Include healthy fats like avocado, olive oil, and nuts in your meals.
• Focus on protein: Include high-quality protein in your diet as it is satiating and leaves you feeling fuller for longer.
• Manage stress: Stress can trigger sugar cravings, so cultivate healthy habits like spending time in nature, meditating, and nurturing relationships to minimize stress.

While it may take some time to adapt to a keto diet, the reduction in cravings is a benefit that many people experience. By following the tips outlined above and sticking to the diet, you can successfully reduce your cravings and reap the benefits of keto-adaptation.

Frequently asked questions