The primary goal of a ketogenic (keto) diet is to shift your body's metabolism from burning sugar to burning fat for fuel, a state known as nutritional ketosis. This is achieved by drastically reducing carbohydrate intake to a very low level, typically between 20 to 50 grams of net carbs per day, which usually accounts for only 5-10% of your total daily calories. This strict carb limit forces your body to produce ketones, which are byproducts of fat burning that can be used for energy.

A "low-carb" diet is a broader term for any eating plan that restricts carbohydrates, but usually to a more moderate level of 50 to 100 grams of net carbs per day (10-20% of calories). While a keto diet is a type of low-carb diet, not all low-carb diets are ketogenic because this more moderate carb intake may not be low enough to consistently keep someone in ketosis.

This distinction is a frequent point of frustration among viewers in the sources, as some studies label diets with up to 40% of calories from carbohydrates as "low-carb," which is not representative of a true ketogenic diet and can lead to misleading conclusions. The choice between a strict keto diet and a more moderate low-carb approach often depends on your level of insulin resistance and personal health goals.

According to the sources, several common mistakes can prevent people from achieving their desired results on a keto diet. These include:

• Consuming too much dietary fat for too long: While adding healthy fats is essential at the beginning, continuing to eat excessive amounts of fat after your body has become "fat-adapted" can prevent you from burning your own stored body fat.
• Not transitioning to fewer meals: Many people find long-term success by combining keto with intermittent fasting, eventually progressing from three meals a day to two, or even one. Eating too frequently, even keto-friendly foods, can keep insulin levels elevated and lead to plateaus.
• Over-relying on "keto" treats and desserts: Using fat bombs, keto bars, and other processed keto-friendly sweets can keep sugar cravings alive and stall weight loss. One expert advises replacing the dessert habit with a non-food activity that stimulates feelings of comfort and reward, such as playing a game, writing in a gratitude list, or spending time with a pet.
• Not measuring ketone levels: It's a common mistake to assume you are in ketosis without actually measuring. As the body adapts, ketone production can change, and accurate measurement with a blood or breath meter is crucial for tracking progress and making necessary adjustments.
• Focusing too much on lean protein: The keto diet is a high-fat, moderate-protein diet. Consuming very lean protein sources, especially protein powders, can sometimes raise insulin levels more than fattier sources of protein, which can interfere with ketosis.

The "keto flu" refers to a collection of symptoms like fatigue, muscle cramps, and headaches that some people experience when first starting a ketogenic diet. According to the sources, these symptoms are often not a result of the diet itself but are primarily caused by an electrolyte imbalance.

When you significantly reduce carbohydrate intake, your body tends to excrete more water, and along with it, essential minerals. To prevent or manage the keto flu, it is critical to replenish these electrolytes, specifically:

• Sodium
• Potassium
• Magnesium

This can be done by using a sugar-free electrolyte supplement, adding more salt to your food, drinking pickle juice, or consuming electrolyte-rich foods. Some experienced commenters noted that the required amounts can be much higher than people realize, suggesting intakes as high as 5,000-7,000 mg of sodium per day, depending on activity levels.

This is a point of considerable debate in the sources, with varied experiences reported.

• Initial Adaptation Phase: It is common to experience a decline in workout intensity and performance during the initial transition to a keto diet, which can last four weeks or more. This happens because your body is depleting its stored carbohydrates (glycogen), its usual go-to fuel source for intense exercise.
• After Fat-Adaptation: Many commenters and some experts suggest that once your body becomes "fat-adapted," it learns to efficiently use fat and ketones for energy. This may allow you to maintain and even build muscle. In fact, one study mentioned, 43% of patients with chronic, treatment-resistant mental illness achieved clinical remission while on a ketogenic diet. Some athletes report feeling more sustained energy and endurance once adapted.
• Preserving Muscle: The key to preserving muscle on any diet, including keto, is to ensure you are consuming adequate protein and sufficient total calories. Your body can also create its own glucose from protein through a process called gluconeogenesis, which can fuel the cells that require it without breaking down muscle, provided your macros are balanced.

However, some sources express skepticism, pointing to studies where athletes were unable to retain muscle on keto and arguing that the lack of carbohydrates inherently compromises high-intensity training. Ultimately, sustainability is highlighted as the most important factor for any long-term fitness plan.

Many personal stories and expert discussions in the sources suggest the ketogenic diet may offer therapeutic benefits for various conditions, but it's crucial to proceed with medical supervision.

• For Diabetes: Many individuals report using a keto diet to reverse type 2 diabetes, lower their A1C, and reduce or eliminate medications. Some with type 1 diabetes also report achieving much better glycemic control. However, this is one of the most critical areas where consulting a doctor is non-negotiable. The diet can be so effective at lowering blood sugar that medications like metformin or insulin may need to be adjusted immediately to prevent dangerously low blood sugar (hypoglycemia).
• For Mental Health: The emerging field of metabolic psychiatry views the keto diet as a "brain metabolic therapy". The diet may help manage conditions like anxiety, depression, bipolar disorder, schizophrenia, and ADHD by reducing brain inflammation, oxidative stress, and insulin resistance. In one study mentioned, 43% of patients with chronic, treatment-resistant mental illness achieved clinical remission while on a ketogenic diet. Many commenters shared personal stories of their anxiety and depression resolving on the diet.
• Other Conditions: Viewers frequently ask about using keto for fatty liver, high cholesterol, PCOS, and kidney disease, underscoring the need for personalized medical guidance for any chronic condition.

Getting into ketosis involves depleting your body's stored carbohydrates (glycogen) so it switches to burning fat for fuel.

• How to Enter Ketosis: A three-step method described in the sources is to first perform 20 minutes of maximal-effort exercise, like sprints, to burn through glycogen stores quickly. This is followed by a high-fat, moderate-protein, very-low-carbohydrate meal. Consuming fats like MCT oil or coconut oil can be particularly helpful, as they are converted to ketones more rapidly by the liver. Finally, you would fast for at least 12 hours, which can be done overnight while you sleep. Simply fasting for 18-36 hours without the other steps is also an effective way to enter ketosis.
• How to Measure Ketosis: The only way to know for sure if you are in ketosis is to measure the level of ketones in your body. Nutritional ketosis is generally defined as having a blood ketone level of 0.5 millimoles per liter (mmol/L) or higher.
  • Blood Ketone Meters: These are considered the most accurate method for tracking ketosis.
  • Breath Ketone Meters: Certain medical-grade devices, like Biosense, are also considered accurate alternatives.
  • Urine Strips: These can be a cost-effective and motivating tool for beginners. However, they measure excess ketones excreted in urine and become unreliable for long-term use once your body becomes more efficient at using ketones for fuel (a state known as "fat-adapted").