The keto diet is a low carb, moderate protein, high fat diet which helps the body to produce ketones in the liver to be used for energy. When you eat something high in carbs, your body will produce glucose and insulin. Glucose is the easiest molecule for your body to convert and use as energy. The body will choose glucose over any other energy source. Insulin is produced to process the glucose in the blood by moving it around the body. Because glucose is being used as a primary energy source, fats are not needed and are, therefore stored as body fat. On a normal, high carb diet, that most Americans eat, the body will use glucose as the main form of energy. By lowering the intake of carbs, the body is forced to use fat as its energy source. This process is known as ketosis
Ketosis is a natural metabolic process the body initiates to help it survive when food intake is low. It also occurs when the body does not have enough glucose for energy. This results in a buildup of acids called ketones, which are produced from the breakdown of fats in the liver. It takes one- two weeks for the body to fully shift into ketosis, so you'll need to be patient in early keto. If you're combining intermittent fasting (see upcoming article on intermittent fasting) and restricting your carb intake to under 20 net grams a day, you might enter ketosis in a little as 4 days. There are several signs that indicate that you're in ketosis.
During the first few days of keto you may feel tired. You may have a headache or even feel a little sick. This is known as the KETO FLU. This is temporary and normal. Signs that your body is in ketosis include increased energy, weight begins to drop, increased ketone levels (several home tests are available to measure ketone levels). The one sign that you can't miss is that your urine may have a strong pungent smell like nail polish remover! It might not be a great scent, but it's a great sign that you've entered into the state of ketosis. It's a sign of ketones in action.