The keto diet’s main argument is its promise of rapid and effective weight loss, which draws people seeking weight management, improved performance, or new dietary trends. Its low-carb, high-fat structure claims unique metabolic benefits as ketosis occurs.
It remains debated whether the keto diet is truly the optimal approach for weight loss and athletic performance, and for whom it is most suitable.
Understanding the core promise and the audience drawn to the keto diet clarifies why its popularity has grown beyond medical use.
What is a ketogenic diet?
Today, many individuals interested in weight management, fitness, or popular health trends are familiar with the ketogenic diet. Its following includes people aiming for weight loss, fitness enthusiasts, and some patients with special health needs.
The diet’s reduction in carbohydrates and focus on high fat aims to induce ketosis, where the body uses ketone bodies for energy instead of glucose.
The strictest ketogenic diets have up to 90% fat, with only 5% carbohydrates and protein. This extreme ratio was originally intended for specific medical, not general, use.
The ketogenic diet began as a therapy for conditions like childhood epilepsy resistant to medication, used since 1921. It later gained popularity for weight loss, especially among athletes and bodybuilders in the 1970s.
Having clarified what the ketogenic diet entails, it is helpful to explain the concept of ketosis, which is central to how the diet functions.
The main goal of the ketogenic diet is to shift metabolism so the body uses fat, not carbohydrates, for energy, producing ketones in the process.
Normally, our bodies use glucose, with the brain requiring about 150 g daily. Reducing carbs prompts the liver to produce ketones, such as acetone, B-hydroxybutyrate, and acetoacetate from fat. In ketosis, these ketones fuel muscles, the heart, and the brain instead of glucose.
How is nutritional ketosis different from diabetic ketoacidosis?
Nutritional ketosis and diabetic ketoacidosis sound similar but differ greatly. Nutritional ketosis is planned, with safe levels of ketone bodies as the body shifts to fat metabolism.
Diabetic ketoacidosis, on the other hand, is a serious complication of poorly treated diabetes. This applies mainly to type 1 and sometimes type 2 diabetes. In this case, a lack of insulin means not enough glucose enters the cells for energy.
The body then forms excessive ketone bodies, leading to acidosis in the blood. This condition is life-threatening and requires hospitalisation. However, this is not a state that a healthy person would enter by following a ketogenic diet.
What ratio of nutrients does the ketogenic diet have?
Achieving ketosis requires a strict macronutrient balance. For epilepsy therapy, up to 90% of calories are fat, with only 5% or less as carbohydrates and protein. Precision ensures therapeutic results.
As with medication, therapeutic ketogenic diets demand precision and consistency. Patients have calculated, individualised nutrition, and are supervised by doctors with tailored supplements and foods.
What does the ketogenic diet for weight loss look like?
These strict requirements do not apply to most adults pursuing weight loss or fitness using keto. For this audience, the diet remains strict but is more practical for general use.
For weight loss, fats should provide about 70-80% of daily energy, carbohydrates must stay below 50 g (10% of a 2000 kcal diet), and protein makes up 10-20%.
Carbohydrates must stay below 50 g per day to induce ketosis, equal to 10% of a 2000 kcal diet.
Proteins should make up 10-20% of daily intake.
This more practical version of the keto diet is often used by those targeting weight loss or fitness, rather than for medical therapy. For these audiences, both approaches still restrict carbohydrates and increase fat to induce ketosis, but differ in strictness.
Any diet, including keto, requires a calorie deficit for weight loss. Ketosis does not override this need. However, keto may help some maintain a calorie deficit more easily.
How does the keto diet help you lose weight?
The keto diet helps burn stored body fat by inducing ketosis. This metabolic shift enables the body to use fat as its primary energy source.
Fats are burned for energy in mitochondria through beta-oxidation, and ketogenesis in the liver forms ketone bodies when carbohydrate intake is low. Low insulin levels make body fat more accessible, supporting weight loss.
The body adapts rapidly to the keto diet; this is crucial since the brain requires up to 20% of the body’s total energy.
Types of ketogenic diet
There are several types of keto diets, differing mainly in calories and macros. Carbs should stay below 50 g.
The standard ketogenic diet is 70-80% fat, 10-20% protein, and 5-10% carbohydrates. The nutrient ratio always depends on individual needs.
The MCT keto diet keeps the standard macros but raises MCT fat intake. MCTs digest faster and may allow slightly more carbs and protein while maintaining ketosis.
A calorie-restricted keto diet keeps the standard ratios, but with fewer total calories.
A cyclic ketogenic diet allows more carbs on some days. For example, five low-carb days followed by two higher-carb days. This can make adherence easier for some.
The Targeted Ketogenic Diet (TKD) has a nutrient ratio similar to standard. Here, carbohydrates are eaten around training.
The powder keto diet is often marketed as a simple solution, but keto can include regular foods. If using instant mixtures, check their nutrient ratios, as many fit high-protein plans instead of keto.
What is the difference between a keto diet and a low-carb diet?
Low-carb diets have long supported weight loss. The key difference is carbs: keto allows up to 50 g/day, while other low-carb diets allow 50-150 g (per 2000 kcal). Only keto induces ketosis.
Benefits of the keto diet
1. Helps to lose weight more effectively
Nutritional ketosis distinguishes the keto diet, making weight loss a bit easier for some. Research finds keto users often lose weight faster than with other diets.
Such results emerged, for example, from a study that followed 322 obese people over two years. The participants were divided into three groups: one adhered to a low-fat, low-calorie diet, another to a Mediterranean, low-calorie diet, and the third group was on a keto diet with no calorie restriction.
They were allowed only 20 g of carbohydrates/day for the first two months, and the rest of the time the carbohydrate intake limit was 120 g (total caloric intake remained the same). As a result, the most successful group was the one that followed the ketogenic diet.
Participants lost the most weight when their carbohydrate intake was 20 grams. After increasing the intake of carbohydrates, the weight increased slightly. The benefits of ketosis appear to have been reflected in these results, which we will now discuss in more detail.
What makes the keto diet easier to lose weight?
Several factors help burn fat more efficiently and support a calorie deficit.
- Fat burning increases as fatty acids from stored body fat are converted into ketone bodies and used for energy.
- Ketones can help reduce appetite.
- Lower carbohydrate intake reduces insulin, promoting fat breakdown.
- Sudden weight loss at the beginning of a diet is also associated with loss of body water.
The ketogenic diet is not suitable for everyone, but if it suits someone, it can help them with weight loss and somewhat accelerate it. However, anyone who has such a set regime should note how their body reacts to such a strict change.
There may be side effects of the diet, such as nutritional deficits and others, which we will discuss later. In any case, it is advisable to increase carbohydrate intake after the ketogenic diet fulfils its purpose, and maintain weight (or lose weight further) with a more varied and less strict diet.
2. Reduces appetite
A common weight loss challenge is hunger and cravings. While a proper routine should minimise this, cravings often derail efforts. The keto diet often reduces hunger and cravings, making a calorie deficit easier to maintain.
Several factors contribute to this effect.
- High levels of ketone bodies can suppress appetite by influencing how the brain signals hunger and satiety.
- An effect on reducing ghrelin levels – the hunger hormone – is also shown.
So-called sensory-specific satiety also plays a role in this. This is a phenomenon that occurs when we consume the same foods repeatedly over a long period.
Since the keto diet is relatively monotonous, after a certain time, some foods are not as attractive, we do not feel the need to eat as much of them, and thus, we create a calorie deficit.
3. Helps maintain stable blood sugar levels
Normal blood sugar levels (glycemia) should be sought not only by people with diabetes, but also by ordinary healthy mortals who want to maintain good health for as long as possible.
Stable glycemia helps maintain functional and healthy blood vessels. In addition, its fluctuations can be commonly manifested by a sweet tooth or a lack of energy. Because of this, we often indulge in some sweetness or snack beyond our optimal caloric intake.
Glycemia during the keto regimen is typically lower due to minimal carbohydrate intake. In addition, because the body provides itself with ketone bodies as an alternative energy source, it does not have to make glucose from proteins and other sources at all costs.
A Keto diet can be beneficial when the goal is to keep blood sugar levels low and stable. Thanks to this, we achieve a more balanced energy level, fewer cravings, and when we no longer need to reach for chocolate after every lunch, it is easier to maintain a calorie deficit.
Is it suitable for diabetes?
The effect of the keto diet on diabetes is now well understood. Studies tell us that it can be beneficial in this disease because it has been shown to help improve glycemic control, reduce insulin requirements, and reduce the risk of complications.
This applies to diabetes 1 and type 2 diabetes. In the case of type 2 diabetes, the type, which is mostly associated with obesity and an incorrect lifestyle, can also lead to an improvement in insulin resistance. It can be an interesting way to take care of this disease to the next level.
However, this procedure should always be consulted with a doctor and a nutritionist, as it is not without risks. Especially with type 1 diabetes, it is important to strictly monitor the process, as the already mentioned ketoacidosis threatens. Diabetics 2. They can cause hypoglycaemia (too low blood sugar).
Despite these benefits of the keto diet, it is certainly not the place to condemn a normal, rational diet. It has long been known to keep blood sugar levels under control in healthy people and those with diabetes. It depends on which procedure suits us better.
4. It is beneficial for the nervous system
The incidence of various neurological diseases is on the rise today, and therefore, ways are being sought to effectively combat them. As we have already mentioned, the ketogenic diet was primarily created to help manage epilepsy in children who do not respond to available medications.
However, it has gradually been shown that it can have a positive effect on other neurological diseases. The role in this is played by the emerging ketone bodies, which serve as an alternative source of energy for the brain.
This process can have neuroprotective and anti-inflammatory effects, as well as affect the energy metabolism in the brain. The diet could be beneficial for Alzheimer’s disease, multiple sclerosis, Parkinson’s disease, or even migraines.
5. Can improve cardiovascular health
The effect of the keto diet on the heart and blood vessels is a long-debated question, to which, however, scientists still do not have a clear answer. Until recently, excessive intake of fat, especially saturated fat, was considered a great risk for our cardiovascular system.
However, today’s view tells us that it is not so much about how much saturated fat we eat, but rather in the form of what foods we consume. Therefore, especially highly industrially processed foods, in which SAFA is combined with trans fatty acids, preservatives, salts, and other substances, are at risk.
This view is confirmed by many studies that track the effect of the keto diet on cardiovascular health. It turns out that, despite its high fat content, it acts more positively than negatively.
What are the benefits?
- It can increase the level of HDL (good) cholesterol.
- In studies, there is also a decrease in triglycerides in the blood.
It also shows an improvement in the ratio of LDL cholesterol subtypes, an increase in the amount of large, less harmful LDL particles, and, conversely, a decrease in smaller ones, which are more risky for the body.
However, despite these advantages, it should be remembered that the keto diet may not be suitable for everyone. Some studies do not confirm this view, which only emphasises that we are all unique and our bodies can react differently, not only to keto diets.
In addition, we do not have enough scientific work to study the long-term effects of this diet on health. Therefore, again, it is important to consult a specialist and honestly monitor how our body reacts to a new diet.
Risks of the keto diet
While some people benefit greatly from the keto diet, it can cause problems for others. Therefore, it is important to consider whether it is the right choice for you. In particular, long-term compliance with this regime is a risk. Its effect on overall health over a 2-year diet is not well documented.
1. It can cause the so-called keto flu.
Changing from a normal diet to a keto diet is quite a big shock to the body. Often, short-term side effects occur as a result, collectively known as “keto flu”, that is, keto flu.
What kind of speeches are they?
- Nausea.
- Headache.
- Fatigue.
- Dizziness.
- Insomnia.
- Vomiting.
These symptoms typically accompany the initial phase of the diet and disappear within a few days. It can help relieve them of an adequate drinking regimen and intake of electrolytes and other important micronutrients. If they persist or worsen, it’s time to consider whether a keto diet is the right choice.
2. There is a risk of nutritional deficits
The Keto diet limits a large number of foods and even entire food groups. Therefore, there is a risk that the body will not receive enough vitamins, minerals, and other essential nutrients.
What is the body missing?
Fibre, because the keto diet practically completely limits the intake of cereals, legumes, fruits, and some vegetables. These are the main sources of fibre in our diet. To prevent constipation and other digestive and health problems, it is important to take fibre in the form of supplements.
Vitamin C is found mainly in fruits and vegetables, so there is a risk of its deficiency. At the same time, it is necessary for the proper functioning of immunity, or, for example, the production of collagen. To ensure that its daily intake is sufficient, it can be taken, for example, in the form of classic or effervescent tablets or as a powder.
Magnesium is found mostly in cereals, which are foods that are practically not present in the keto diet. It can be supplemented in the form of capsules, effervescent tablets, or even a shot. Magnesium is needed for the proper functioning of muscles, the nervous system, and the psyche.
Vitamin D can also be in short supply, as the keto diet also restricts dairy products. However, our body needs it for the proper functioning of immunity and to maintain the normal state of bones or muscles.
B vitamins are found in virtually all foods. However, some of them are typical of those that the keto diet prohibits. For example, thiamine (Vitamin B1) or folic acid in large quantities can be found in cereals or legumes. Vitamins of Group B are important for energy metabolism, play a role in immune, nervous, and other functions, so we should never neglect them in the diet.
Calcium is mainly contained in dairy products, which are absent in the keto diet. However, supplementation will make sure that our bones, teeth, and nervous system are not missing.
To avoid these deficits, it is important that the keto diet is well planned, including an adequate intake of permitted vegetables, sources of quality fats, and dietary supplements.
3. Can lead to digestive problems
The Keto diet is low in fibre and rich in fat, which is a combination made for digestive problems. There may be a diverse range of difficulties, from flatulence, bloating, irregularities in emptying, diarrhea, and constipation.
Therefore, it is important to consume enough vegetables, supplement with fibre, while not forgetting about the drinking regime and sufficient physical activity.
4. It can negatively affect the psyche
Like other strict and restrictive diets, keto can affect mental health. Whether we like it or not, food is an important part of our daily lives, so it naturally has a say in how we feel right now.
And of course, we all know that we are better off when we can enjoy our food. However, the Keto diet is so restrictive that for many, it can be more of a torment than a pleasure. This can often cause stress or frustration that we have to limit ourselves too much.
It can lead to social isolation, forcing us to avoid social events because they are usually full of good food, which the keto diet prohibits.
With such strict control, an unhealthy relationship with food goes hand in hand. We often see that strict dieting can increase the risk of developing an eating disorder, such as orthorexia (obsessive focus on food) or binge eating.
Therefore, if you are considering a keto diet, be sure to take into account its possible negative impact on the psyche when making a decision.
5. May cause bad breath
Does this seem like a strange symptom of a diet to you? In fact, this is logical because one of the ketone bodies that is formed during ketogenesis is acetone. You may know it as part of a nail polish remover, for example.
This substance is formed in the body when the body is in ketosis. If the formation of acetone is within healthy limits, it is not harmful to the body, but it can be manifested precisely by bad breath.
How to start a keto diet?
Have you weighed all the pros and cons and decided that you want to embark on a keto diet? In this case, you should not neglect some important steps.
How to do it right?
Learn about the keto diet. To get the most out of it, you need to know how it works and on what principle it stands.
Discuss this choice with a nutritionist:
- In advance, be prepared for possible side effects that may occur at the beginning of the diet.
- Set yourself the right amount of energy and nutrients.
- Plan your meals.
- Keep track of your progress.
- Observe the drinking regime.
- Do not neglect motor activity.
- If necessary, take supplements.
- Watch the effect of diet on your body.
Which foods are allowed on the keto diet?
The keto diet allows you to eat only those foods that contain a minimum of carbohydrates. Which ones are they?
Protein foods of animal origin: meat, fish, seafood, eggs
Foods with a high percentage of fat: vegetable oils, avocados, butter, cheeses (especially hard), nuts and seeds (in a controlled amount due to the carbohydrate content)
Vegetables with a low carbohydrate content: leafy vegetables, broccoli (broccoli, cauliflower, cabbage, etc.), cucumbers, celery, peppers, zucchini
However, today it is not necessary to limit ourselves to these basic raw materials. There are also a variety of low-carb foods that can replace foods from the list of unsuitable ones. People on a keto diet can reach for low-carb bread and other baked goods, pasta, or even rice without carbs.
What do you get out of it?
Today, the ketogenic diet has a place of Honor in the fitness world, as it has built a reputation as a successful diet for weight loss. This is actually confirmed by studies that say that due to the induced state of ketosis, the body burns body fat more easily.
There is also talk of its health benefits, such as a positive effect on glycemia or cardiovascular health. However, on the other hand, this is a completely extreme diet with a minimum amount of carbohydrates and a very high percentage of fat.