How does the ketogenic diet work?

The body obtains glucose from simple carbohydrates, such as milk, sugar or fruit, or from complex carbohydrates, such as cereals, flour, pasta or legumes. The glucose that circulates in the blood, is stored in the liver or in the muscles in the form of glycogen, is the main source of energy for the entire body, especially for the brain and heart. So, as long as glucose, or failing that glycogen, exists, the human body does not use its fat reserves.

In this regard, the keto diet consists of reducing the intake of carbohydrates and increasing the content of proteins and healthy fats, in proportions of between 50 and 60% fat, 20 to 30% protein and 10%, or less of carbohydrates.

The body obtains glucose from simple carbohydrates, such as milk, sugar or fruit, or from complex carbohydrates, such as cereals, flour, pasta or legumes. 

The glucose that circulates in the blood, is stored in the liver or in the muscles in the form of glycogen, is the main source of energy for the entire body, especially for the brain and heart. So, as long as glucose, or failing that glycogen, exists, the human body does not use its fat reserves.

In this regard, the keto diet consists of reducing the intake of carbohydrates and increasing the content of proteins and healthy fats, in proportions of between 50 and 60% fat, 20 to 30% protein and 10%, or less of carbohydrates.

What benefits does the keto diet provide?

The keto diet can provide many benefits, including:

Increases satiety and decreases appetite. Numerous studies have established that a diet based on the parameters of the ketogenic diet -the consumption of fats and proteins- helps to control hunger, because it generates a feeling of satiety for a longer time.

Avoid heart disease. It can improve risk factors such as body fat, HDL cholesterol levels, blood pressure, and blood glucose level.

Reduces epileptic seizures. Scientific research supports that the keto diet can greatly reduce epileptic episodes in children.

It helps patients with type 2 diabetes. Its benefit for diabetic patients is that it controls blood sugar levels, and on the other hand, it decreases and reduces the negative impact of high insulin levels.

Used in the prevention and treatment of certain types of cancer. Reducing carbohydrate intake lowers glucose levels, which is the fuel that fuels cancer cells. This diet is also used to treat many types of cancer and reduce the growth of tumours.

Scientific evidence that the keto diet works

There are at least 31 randomised controlled trials showing faster weight loss with low-carb diets, according to the latest report from the UK Public Health Collaboration. Three of these studies published by renowned scientific media are:

Annals of Internal Medicine year 2004. This medical journal of the American College of Physicians published a study that showed that compared to a low-fat diet, a low-carbohydrate diet program reported greater weight loss.

New England Journal of Medicine year 2008. This journal published by the Massachusetts Medical Society (USA) discussed a two-year study in which 322 people were randomly assigned to follow a Mediterranean diet, a low-fat diet and a low carbohydrate diet. At the end, the low-carb group had lost more weight than the rest.

The Journal of Nutrition 2015. This journal from the American Society for Nutrition discussed research that revealed that a low-carbohydrate, high-fat diet reduces abdominal and intermuscular fat and increases insulin sensitivity in adults at risk for diabetes type 2.

How is the keto diet done?

Ketogenic diets are characterised by menus of five meals , where eggs , meat, dairy, vegetables, fish, nuts and seeds are the protagonists. In addition, there is a large presence of foods rich in healthy fats such as avocado or fish such as tuna, cod or salmon.  

In order to reach the state of ketosis in the keto diet, simple and complex carbohydrates are reduced as much as possible. Depending on the circumstances of each person and their physical condition, the maximum limit of daily carbohydrates is usually established between 20 and 50 grams. 

The approximate ratio of daily calorie intake on the keto diet is:

  • 60 to 75% fat.
  • 25 to 30% protein.
  • 5 to 10% carbohydrates.

Foods to eat on the keto diet

A ketogenic diet consists mainly of getting calories from fatty foods and some protein. To achieve this, meals should be made around the following foods:

  • Meat. Red meats, ham, sausages, chops, chicken and turkey.
  • Cheeses. Unprocessed cheeses, such as cheddar, goat, cream, blue, or mozzarella.
  • fatty fish. Such as salmon, trout, tuna and mackerel.
  • Eggs. Preferably rich in omega-3 and pasteurised.
  • Nuts and seeds. Among them are flax seeds, pumpkin, chia, almonds and walnuts.
  • Healthy oils. The best ones are extra virgin olive oil, coconut oil and avocado oil.
  • Avocado. They are consumed whole or in guacamole made naturally.
  • Low carb vegetables. Among these are the most green vegetables, tomatoes, onions and peppers.
  • condiments. Food can be seasoned with salt, pepper, and some healthy herbs and spices.
  • KETO products: there are specific preparations for this type of diet, shakes, bars , snacks...

Foods to avoid on the keto diet

On the keto diet, you should avoid any foods that are high in carbohydrates. Foods that are reduced or eliminated on the ketogenic diet include:

  • sugary foods The consumption of soft drinks, fruit juices, milkshakes, ice cream and sweets is avoided.
  • Fruit. All fruits are allowed, with the exception of small portions of forest fruits, such as strawberries.
  • Cereals or starches. Products derived from wheat, rice, pasta and cereals are eliminated.
  • Dietary product. They are not consumed as they are highly processed and rich in carbohydrates.
  • Some condiments or sauces. Those that contain sugar and saturated fats are avoided.
  • Saturated fats. The intake of refined oils and mayonnaise is limited.
  • Alcohol. Because of their high carbohydrate content, many alcoholic beverages are eliminated on this diet.
  • Beans or legumes. Peas, kidney beans, lentils and chickpeas are not consumed.
  • Root vegetables and tubers. Potatoes, sweet potatoes and carrots are eliminated.

Sample Gourmet Keto or Ketogenic Diet

Charles Orrico, nutritionist at the Fit Club Madrid gym, proposes a gourmet menu for one day that meets the requirements of a ketogenic diet:

  • Breakfast. Cheese tortillas and natural nuts.
  • Food. Salmon with vegetables such as broccoli, kale, cabbage, spinach and olive oil.
  • Afternoon snack. Tuna and avocado tart.
  • Dinner. Grilled fish with vegetables and an ounce of dark chocolate for dessert.

weekly ketogenic meal plan

In a weekly projection of the keto diet, the options to eat would be the following:

Breakfast. Based on bacon, eggs, tomatoes, basil , goat cheese omelette, ketogenic milk shakes, omelette with avocado, salsa, peppers, onions and spices, sugar-free yoghourt with peanut butter, cocoa powder and stevia and corn omelette. cheese and ham with vegetables.

Food. They can be made with chicken salad with olive oil and feta cheese, seafood salad with olive oil and avocado, sliced ​​ham and cheese with walnuts, hamburger with sauce, cheese and guacamole.

Dinner. You can use salmon with asparagus cooked in butter, meatballs, cheddar cheese and vegetables, pork chops with Parmesan cheese, broccoli and salad, chicken stuffed with pesto and cream cheese accompanied by vegetables, burgers with bacon, egg and cheese, white fish, eggs and spinach cooked in olive oil.

Ketogenic snacks. A handful of nuts or seeds, cheese with olives, 1 or 2 hard-boiled eggs, 90% dark chocolate, a low-carb milkshake with almond milk, cocoa powder and nut butter, whole milk yoghourt with nut butter , cocoa powder and strawberries with cream.

Advantages and disadvantages of the keto diet

When you enter a state of ketosis, fatty acids are transformed in the liver in a metabolic process that seeks to obtain energy quickly. This is when ketones are released, molecules that the body now uses as an energy source.

In the presence of ketosis, the body becomes incredibly efficient at converting all fat into energy , it can also supply more energy to the brain. However, in addition to these advantages, their disadvantages must be weighed.

Advantages of the keto diet

  • The keto diet could reduce Alzheimer's symptoms and slow its progression.
  • The ketogenic diet can help lower insulin levels, which may play a role in PCOS.
  • Lowering insulin levels and reducing your intake of sugar or processed foods may improve acne.
  • By burning fat, it contributes to faster weight loss.
  • It helps to have a more constant energy and a higher mental performance.
  • Improves cholesterol, blood sugar and insulin levels and blood pressure.

Disadvantages of the keto diet

  • It is not recommended for people with metabolic diseases.
  • It is still the subject of medical and nutritional research.