The ketogenic diet is one of the most well-known and effective ways you can lose weight with the right dietary habits, improve your stamina and optimize your health.
If you perform the ketogenic diet conscientiously, you will forgo much of the carbohydrates in your diet, giving your body less glucose available to produce energy from it.
As a result, your body starts by extracting energy from fats by burning fat tissue and converting fats it gets through your diet into so-called ketone bodies [1, 2].
The process of this transformation is called ketosis. If your body wants to gain energy from glucose, it needs insulin to do so. However, this substance is not needed when the metabolism of fats and ketones.
The ketones that are not used by your body for energy production enter your urine via your kidney, where they are ultimately excreted by your body.
How do you know if you’re in ketosis?
This question is posed by almost everyone who starts with the ketogenic diet.
To establish this is not so easy. Relying on your own feeling can quickly lead to misunderstandings and is not a good way to determine if your body is already producing ketones.
Since it is incredibly important to know whether your body is already in ketosis or not, here are the most common symptoms and signs of ketosis.
If you notice one or more of them, it is likely that your metabolism has changed accordingly and you can enjoy the benefits of ketosis.
Common signs and symptoms of ketosis
1) Weight loss
The ketogenic diet is similar to normal low-carb diets an effective way to break down adipose tissue in a short period of time and lose weight as a result [3, 4].
There are a variety of studies on weight loss, all of which confirm that the ketogenic diet can have both short-and long-term benefits on your body fat percentage compared to a normal diet .
So once you start with the ketogenic diet, you may lose weight excessively quickly, especially in the first week. While most people think that the first fat pads are already burned here, your body consumes the remaining carbohydrate stores and excess water depots .
After the first, rapid downward movement of your body weight, a phase of constant fat burning follows, as long as you adhere to the principles as well as the rules of the ketogenic diet and you eat the right ketosis foods.
A first sign of ketosis is rapid weight loss due to the consumption of carbohydrate stores and water depots. After that, your body starts burning fat.
2) Increased ketone levels in your blood
One of the most striking signs that you are in ketosis is the reduction of your blood sugar levels and an increase in the number of ketones in your blood.
The longer you stick to the ketogenic diet disciplined, the faster your body will start using fat as its primary energy source.
To measure the number of ketones in your blood, you should buy a special device that measures the number of 3-hydroxybutanic molecules in your blood.
This is one of the most common ketones in your bloodstream. Measurements of ketone levels in your blood are also used in most scientific studies  and a corresponding device costs between 40 and 50 euros.
According to most experts, values of 0.5 to 2 mmol/liters speak of the metabolic state of ketosis. This area should therefore also be your target area if you want to lose weight quickly and have more energy.
Here is an understandable overview of the optimal keto zone as well as an explanation from when one speaks of ketosis and from what values it can become dangerous.
The most accurate way to determine if your body is already in ketosis is to measure the number of ketones in your blood.
3) More ketones in your urine and breath
In addition to analyzing your blood, there are other ways to measure your ketone levels.
One of these methods is to measure your breathing on the level of acetone. This molecule is one of three types of ketones that can be found in your blood when you are in ketosis [8, 9].
The use of acetone breathing measurements is relatively accurate, but less accurate than measuring ketones directly in your blood.
Another good and simple method for measuring ketones in your blood is urine rapid testing. You use special indicator strips that allow you to test your ketones on a daily basis.
The disadvantage of this method is that it is not really accurate and therefore does not apply in scientific studies. Nevertheless, you can easily detect the first signs of ketosis.
You can measure the number of ketones in your blood using indicator strips for your urine or devices that analyze your breath. However, these methods are less accurate than direct blood tests.
4) Improved attention and concentration
When people start the ketogenic diet, they mostly feel tired and powerless in the first few days. These first signs of ketosis are called keto flu and the effect is due to your metabolism needing a certain amount of time to change accordingly.
Following these first days, most users then report improved attention and more concentration. At the same time, you can increase your energy level with the right foods.
That’s because ketones are an extremely powerful source of energy for your brain. Ketones have been tested in a variety of studies and have been proven to be capable of inhibiting cognitive disorders and counteracting memory loss [10.11.12].
Therefore, people who adhere to the ketogenic diet disciplined for an extended period of time often report mental clarity and improved cognitive functions [13, 14]. Therefore, improved concentration after a few days or weeks is another sign that you are in ketosis.
Many users of the ketogenic diet report improved concentration and more focus. This is due to the higher number of ketones and lower blood sugar levels.
5) Less appetite
Many people report reduced hunger and less appetite during the ketogenic diet. Even experts, however, are not yet entirely clear why.
This symptom is thought to have to do with eating more protein and more vegetables in the ketogenic diet. In addition, the household of those hormones responsible for regulating hunger and appetite is changing .
Even the ketones themselves can trigger processes in the brain that are ultimately responsible for making you have less appetite . The good thing about it? Intermittent or normal fasting makes it much easier for you.
One of the first signs of the ketogenic diet is a reduced feeling of hunger.
6) Initial fatigue (keto flu)
As described above, many keto beginners feel a kind of fatigue and lack of drive in the first days of the changeover (keto flu). Even if you are a little worse than usual, this is a very good sign that you are on the right track.
You don’t have to worry, because these side effects are perfectly normal. After your metabolism has played into burning carbohydrates for several decades, it takes a certain amount of time to change.
That doesn’t happen overnight. It takes 7 to 14 days for your body to be in full ketosis and for this initial fatigue to be replaced by more energy and motivation.
To counteract this symptom, you should take many electrolytes and the right supplements. Since your body loses a lot of water during this time, you should also consume enough fluid.
In addition, it makes sense to consume 2000 to 4000 mg of sodium, 300 mg magnesium and 1000 mg of potassium daily.
The bottom line
There are some signs and symptoms that you can use to determine whether your body is in ketosis or not.
The most important thing is that you abide by the rules and principles of the ketogenic diet. Then, after a few days, you will be in a changeover phase anyway. The more disciplined you are, the faster you will get into ketosis.
However, to play it safe, you should regularly measure the ketone levels in your blood. To do this, you can choose between indicator strips for your urine or blood tests.
Having said this, you should know that it’s primarily about how you feel during the diet change. If you have more energy, your body burns fat and you feel more alert and healthier, you shouldn’t worry too much about your ketone levels.