The keto diet, short for “Ketogenic diet”, is a low-carbohydrate, high-fat diet. Its primary goal is to induce a metabolic state called ketosis in the body. In ketosis, the body switches from primarily using carbohydrates for energy to burning fat, thus promoting weight loss. Here’s a brief overview of the principles of the keto diet and its contraindications.
Contents
- 1 What is the keto diet
- 2 What is ketosis
- 3 Are we in ketosis? the first symptoms
- 4 The different low carb diets
- 5 Ketogenic diet: how to achieve ketosis
- 6 Ketogenic diet: what to eat
- 7 What to eat in large quantities
- 8 What to eat in moderate quantities
- 9 What not to eat
- 10 Popular foods on the keto diet
- 11 Ketogenic diet and physical activity
- 12 Ketogenic diet: Who can follow it?
- 13 Who can’t follow the keto diet
- 14 The post-diet
- 15 Why didn’t it work on me?
- 16 Keto diet contraindications
- 17 On the same topic
Before illustrating the principles of the keto diet, an important premise should be made. This is a drastic diet that must be monitored by specialized doctors. It is not a do-it-yourself diet precisely because it modifies the processes of our organism. It may not be suitable for everyone, and individuals with certain medical conditions should consult with a healthcare professional before starting the diet.
What is the keto diet
This dietary regime involves the radical reduction of carbohydrates and the increase of proteins and fats.
This diet is usually used to lose weight, but we highlight that it is not a do-it-yourself diet that anyone can follow, it is a difficult diet to follow and which must be followed by a specialist for it to work.
What is ketosis
A ketogenic diet in fact means a diet that produces ketones.
The keto diet is based on the drastic reduction of carbohydrates in the diet: but why? Carbohydrates are the energy source of cells to carry out any activity. If this energy is missing, the body needs to find a substitute: with this diet it will be pushed to use fats as an energy source.
This process is called ketosis and leads to the formation of molecules called ketone bodies: ketosis is reached after a couple of days of a restrictive diet with only 20-50 grams of carbohydrates consumed per day.
To carry out all daily activities, our body metabolizes glycids, such as carbohydrates and sugar, found in the blood. If we suddenly deprive the body of these two elements, it will look to its own reserves present in the body in the form of fats.
Ketosis is therefore induced, the mechanism that pushes the body to burn spare fat because it can no longer find carbohydrates and sugar.
Achieving ketosis and maintaining it unchanged without causing damage is not easy and must be followed by a doctor.
Are we in ketosis? the first symptoms
After a couple of days ketosis should begin. To understand that the body has entered the state of ketosis, a urine test can be carried out with special strips or a blood test using ketone blood meters or breathing tests by measuring the quantity of ketones in the breath.
There are also clear signs that can reveal you are in ketosis:
- exhaustion
- dry mouth and thirst
- increased diuresis
- acetone breath or sweat due to the presence of acetone
- reduction of appetite
The different low carb diets
The keto diet is mainly used to eliminate extra pounds: it only affects fat mass and can achieve good results in a short time.
The keto diet includes different methods which can be distinguished into:
- high-protein ketogenic or Atkins diet;
- normoprotein ketogenic or VLCKD diet used in cases of obesity
- normo-hypoprotein ketogenic which is used not to lose weight but for the treatment of drug-resistant epilepsy
Ketogenic diet: how to achieve ketosis
The keto diet is a nutritional scheme that can be summarized as follows
- low in calories
- low percentage and absolute carbohydrate content (low carb diet)
- with a high percentage of proteins
- with a high percentage of lipids
For the keto diet to work we must first induce ketosis: how?
The first step is to eliminate sources of carbohydrates from your daily diet, such as bread, pasta, potatoes and sugar-based products, but also dairy products, legumes, orange and red fruit and vegetables.
Only meat, eggs and fish are allowed on the ketogenic diet. Food supplements based on vitamins and Omega 3 can be added. It is essential to drink lots of water, at least two liters a day.
The classic food pyramid is completely overturned! Lots of proteins, few cereals and tubers.
Only by respecting the diet imposed by the dietitian can you reach ketosis: you can never go astray because, for example, a piece of candy would be enough to bring the body back to its previous balance and to stop consuming fats to produce energy.
Ketogenic diet: what to eat
The ketogenic diet is a low-calorie, low-carb, zero-sugar, high-protein and lipid diet. What do we eat during our initial three weeks of diet?
A guideline for the correct ketogenic diet involves an energy distribution of:
- 10% carbohydrates
- 15-25% protein
- 70% or more fat
It is advisable to also include supplements in your diet to make up for the lack of mineral salts, omega 3 and vitamins.
Let’s now see what to eat in quantity, what to eat less and what to give up.
What to eat in large quantities
You can eat all proteins of animal origin such as:
- meat, eggs and fish.
- cheeses
- fats and seasoning oils
- vegetables and greens such as: lettuce, broccoli, courgettes, spinach, cardoons, cauliflower, fennel, courgette flowers, radicchio, celery, green peppers, radishes, turnip greens.
What to eat in moderate quantities
These foods can be eaten but in limited quantities, recommended by the doctor:
- vegetables such as: tomatoes, pumpkin, artichokes, green beans, aubergines, red and yellow peppers, asparagus, leeks and onions
- dried fruit, but to be consumed in small quantities.
- fresh fruit only three times a week.

What not to eat
You must avoid all cereals and derived products such as
- bread
- breadsticks
- cracker
- sweets
- pasta
You must also avoid: legumes, potatoes, fruit, sweet drinks, alcohol and foods that may include hidden sugars such as fruit juices, which contain 90% added sugars and only 10% pulp.
Also pay attention to the sugars contained in sweets, chewing gum, medicines, supplements… all it takes is the accidental intake of sugars and ketosis stops: the body would return to functioning as before and the effort made up until then would be in vain.
Popular foods on the keto diet
An example diet for a week
Before starting such a diet, a professional should be contacted. it can be a very dangerous diet for our body if not carried out under strict medical supervision.
With this diet, the loss of 3 kilos per week is possible.
A keto diet strategy usually consists in:
- breakfast: two hard-boiled eggs with a side of sautéed vegetables or a slice of toast with cheese and avocado
- lunch: a turkey burger with a side of cheese and avocado or a salad with turkey, boiled eggs, arugula, avocado, cheese and croutons (30 grams)
- snack: bananas, pineapple, apples, persimmons and mango in moderation or some cheese
- dinner: pork chops with a side of sautéed green beans or grilled salmon with a side of spinach
Ketogenic diet and physical activity
To accelerate and improve the process implemented with a low-calorie diet, it is always advisable to continue with adequate physical activity. Physical exercise must also be recommended by a professional so that good results can be achieved without weighing on a body that is already undergoing major changes.
It is generally recommended to train 3 times a week for at least 30-40 minutes: long walks at a brisk pace, jogging in the open air, yoga practices or swimming are sufficient. It should not be forgotten that doing sports during a period of strong fatigue, such as the start of a diet, helps because it frees the mind and reduces stress.
However, remember that there are conflicting opinions regarding the well-being that physical exercise can offer during a period of ketoacidosis. In fact, it is thought that sport can increase the weight of the ketogenic diet which is in any case a metabolic strain that already weighs on the body, even the youngest one.
Be careful because intense physical exercise increases the energy requirements of glucose, favoring the production and accumulation of ketone bodies. Before carrying out sporting activities, first ask your dietician for advice.
Ketogenic diet: Who can follow it?
Since it is a rather stressful diet for the body, it certainly cannot be continued for long periods and above all it is not suitable for everyone.
Who can follow a Keto diet? Those who suffer from:
- severe obesity;
- mild obesity but complicated by type II diabetes, hypertension, dyslipidemia, metabolic syndrome, arthropathies
- non-alcoholic fatty liver disease
Who can’t follow the keto diet
The ketogenic diet cannot be recommended to anyone:
- who is pregnant or breastfeeding
- suffers from psychiatric and behavioral disorders
- has type I diabetes
- had a myocardial infarction
- suffers from liver and kidney failure
- abuses alcohol and drugs
The post-diet
Once the diet period recommended by the dietician is over, a couple of days of normal eating with the introduction of carbohydrates will be enough and ketosis will end quickly. The body quickly returns to functioning as before.
Usually for long-term maintenance, carbohydrates are slowly reintroduced and periods of ketosis alternate with periods of non-ketosis.
Why didn’t it work on me?
Those trying the diet for the first time may not see results. Achieving ketosis is not immediate and it is not easy, especially the first time.
Therefore, the so-called nutritional ketosis, the process that really burns fat and weight, is not always achieved.
What are the reasons for non-ketosis:
- we still eat too much
- we eat too little
- we eat too much protein: keto is a moderate diet that aims for 20-25% of calories to come from protein
- we eat too many carbohydrates: you should consume 20-50 grams of net carbohydrates per day, no more
- intolerance or allergy to some food. Sometimes food intolerances cause inflammation which in turn can lead to weight gain. While food allergies are serious things and we notice them almost immediately, food intolerances can be more insidious. Some of the most common food allergies include dairy, eggs, peanuts, tree nuts, wheat, soy, fish and shellfish.
Another reason why the body does not go into ketosis may be leptin resistance. Leptin is the hormone that warns the brain that the body is satisfied with the meal, that you are full. It is therefore essential to be able to regulate the consumption of daily meals, especially during a low-calorie diet. If this hormone does not work well it is also difficult to communicate the sense of satiety to the brain and this can be the cause of unmotivated appetite.
Leptin resistance is often caused by irregular sleep, stress, overeating, and calorie restriction. In the case of leprine resistance it may be necessary to wait before seeing even the slightest benefit related to the ketogenic diet, even eight weeks to start seeing results.
Keto diet contraindications
The ketogenic diet used against obesity almost always leads to excellent results in fat mass loss. It must be followed by a specialist, it is not a do-it-yourself diet. It is in fact well known that this diet has different contraindications.
What are the main contraindications of the Keto diet?
- ketosis is considered a toxic condition for the body: the disposal of ketone bodies above normal quantities can in fact cause kidney fatigue;
- maintaining the state of ketosis throughout the treatment is really difficult. It is enough to ingest just one prohibited food to compromise the state of ketosis and push the body to draw energy from sugars
- initially the weight loss is evident but it is very difficult to maintain the weight achieved. There is a high risk of regaining all the weight you lost when you introduce carbohydrates again. The post-diet period is really complex and foods must be reintroduced into your diet gradually. The maintenance period must be followed by a dietician
- ketosis can cause discomfort such as nausea, reduced appetite, dizziness, headache; tiredness; breathing difficulties, constipation, excessive diuresis, sweating and vinegary breath
- it is a diet that cannot be followed for long periods because it is not completely balanced and would damage your health;
- keto diet can cause: hypoglycemia, hypercholesterolemia and hypotension. The patient must then be checked medically.
Remember: always avoid DIY diets. If you intend to follow any diet, not just the keto diet, always consult your doctor and a nutritionist, so that they can provide you with tailored advice.
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