Keto diet

Keto Diet: Definition Of Ketosis, Symptoms And Side Effects

The ketogenic diet is a high-fat, adequate-protein, low-carbohydrate diet that in medicine is used primarily to treat epilepsy.

The ketogenic diet is one of the many dietary regimes available on the market and following a keto diet suggests a high-fat and low-carbohydrate intake that focuses on increasing the ketones present in the blood.

In medicine, it has been used for almost a century in treating epilepsy, among other ailments, and in this article, we will examine the definition of ketosis, what it feels like, what the side effects are, and what food to eat while on the keto diet plan.  

What is the keto diet?

The ketogenic diet or the keto diet, as it is known, is composed of different types of food and beverages that are usually intended to garner specific results such as weight loss or maintain optimum health levels.   

The keto diet menu is explicitly centered around a high intake of fat, a medium intake of proteins, and a low intake of carbohydrates. Given this structure, the body converts fat into compounds known as ketones and begins using them as its primary source of energy.

During the 1920s and 1990s, scientists researched and developed the ketogenic diet in an attempt to cure epilepsy. Although its popularity decreased once anticonvulsive drugs were introduced in the early 2000s, new studies from The Johns Hopkins University advocate for the effectiveness of the keto diet.  

The results were conclusive  in the case of children who have refractory epilepsy reducing the frequency of the seizures due to the body going into ketosis.  Through the use of a controlled diet, the level of ketones in the blood increase and act as substitutes for glucose (a molecule derived from carbohydrates that works as fuel for the brain).

Nowadays, the keto diet is used to cure other ailments as well as manage weight gain, although some side effects might interfere with our bodies, as we’re about to discover in the following article.   

Ketones, ketogenesis, ketosis: General definition 

Generally speaking, ketones (or ketone bodies) are water-soluble molecules that are named after the homonym chemical compound characterized by the presence of a carbonyl group in which the carbon atom is bonded to an oxygen atom.    

Ketones are produced in the liver cells, especially during periods of fasting, intense physical exercise, in conditions such as alcoholism or diabetes, or during low-carb dieting such as the keto diet.

The liver’s job is vital, and it generates ketones as a result of the molecule glucose being intensely produced once its precursor, glycogen, has run low. This process is known as ketogenesis, and it happens once the liver has depleted the glycogen reserves.

Ketone bodies affect multiple organs; for example, they offer a boost of energy to the brain when glucose levels are low.   

After four days of reduced glucose, the majority of the energy provided to the brain will come from ketones. Once this happens, and  we register low-glucose and high-ketones levels, we are experiencing a state called ketosis. 

How to start a keto diet? 

Considering its medical uses, the recommendation is to start a keto diet with the help of a nutrition specialist that can correctly assess each’s needs.

Adjusting to this kind of diet is mostly up to the expertise of the medical staff you have assisting you. It also requires a lot of patience and discipline, especially in the beginning.

Starting and maintaining a keto diet for those interested in curing epilepsy involves three initial stages:   

  • General health check and evaluation of epilepsy, review previous treatment plans, assess mental and physical state of the patient and determine eligibility, create a meal plan.  


  • Start the keto diet followed by periodic medical check-ups, focus on specific protocols such as the fasting protocol for people admitted into the hospital, the protocol for eliminating carbohydrates, and the non-fasting protocol.


  • Fine tuning stage, refers to altering the keto diet plan in accord with the body’s reactions. The most critical phase of the process can take up to 6 weeks to complete.  
Keto diet
The keto diet is a high-fat, adequate-protein, low-carbohydrate diet. | Getty Images

Who can follow a keto diet? 

According to the specialists at The Johns Hopkins Epilepsy Center, the ketogenic diet is recommended to adults with epilepsy that have tried numerous other treatment plans with limited success. 

This dietary regime is advised for adults that undergo vagus nerve stimulation, those who have glucose transporter type 1 (Glut1) deficiency syndrome, diabetes, overweight issues, sleep apnea, or high blood pressure.

The center also recommends the keto diet for young children, but due to the significant side effects it can have, it must be administered under physician supervision.  

Keto diet menu

Planning a keto diet plan requires exhaustive research so that each’s nutritional need is met. Nowadays,  there is software available that can help stay on top of your keto meals, such as KetoCalculator (an online calculator that estimates weight loss and the levels of macronutrients needed).

Similarly to any diet, the keto diet must include a breakfast, a snack, lunch, another snack, dinner, and a final snack before bed.

Generally speaking, keto diet recipes have a few components in common: one of the ingredients has to be high in protein, another high in fat (mayonnaise, butter, olive oil), vegetables and fruit low in carbohydrates (bananas and potatoes), and a fat dairy product (yogurt).

These nutritional guidelines can be used to prepare any meal, including the most traditional or specific ones, in our case. You can cook bacon omelets, salads, or hamburgers but pay attention to the bread intake as it contains a lot of carbohydrates.

Seeing how the ketogenic diet is imbalanced, it could cause a slight deficit in vitamins B and D primarily, which is why these vitamins will have to be supplemented into the menu.  

Each meal can include ingredients such as eggs, meat, milk, tuna, bacon, butter, or cheese, portioned in such a way that it respects the number of carbohydrates we want to lose and the amount of fat we can gain.

In simple terms, this means weighing and tracking each nutrient so that you avoid additional portions. Furthermore, there are special foods designed specifically for use in the keto diet and include products from yogurts down to desserts.

Given the restrictions of the ketogenic diet plan, there are several side effects that we could come across, and it’s important to keep an eye on their development, even mitigate their impact with the help of prescription drugs. 

Keto diet side effects

Due to the high chance of losing essential nutrients during a keto diet, we could experience  side effects such as short-term tiredness, loss of protein, vitamins, and minerals, and a surplus of lipids.

Other common side effects include bad breath, intestinal discomfort (abdominal pain, intolerance to certain foods, constipation, nausea), dehydration and hypoglycemia (especially for those in the fasting stage).

The keto diet side effects also include loss of appetite as well as metabolical changes, in some instances. All of these unwanted effects can be alleviated with the help of a medical specialist, and although they are not severe, it’s essential to prevent any side effects from the beginning of our ketogenic diet. In some cases, alternative regimes can be recommended such as the Atkins diet.   


Bessone, S., (S/A). Ketogenic Diet Basics: The modified Atkins Diet. Available at:

Freeman, J. Kossoff, E., Hartman, A. (2007). The Ketogenic Diet: One Decade Later. Pediatrics Official Journal of the American Academy of Pediatrics, 119: 535-543.

Gowda, V. (S/A). Initiation and maintenance of ketogenic diet.Available at : Initiation and maintenance of ketogenic diet - ResearchGate

Ketogenic Diet Therapy for Epilepsy (2018) The Epilepsy Center. Johns Hopkins University. Available at: