What is ketosis and how is it reached?
Keto diet or Atkins diet ? Ketosis is a condition in which high levels of ketone bodies (ketones) are observed in the body.
Ketones are a group of 3 molecules – acetoacetate (AcAc), tri-beta-hydroxybutyrate (3-β-hydroxybutyrate (3HB)) and acetone (acetone).
Ketones can be seen as an alternative fuel. AcAc and 3HB can also be used as a source of energy by many organs in the human body when needed.
Most readers probably know that the human body relies on three essential nutrients as a source of energy – carbohydrates, fats and protein. Carbohydrates and fats are the main source of energy, and protein is used as such to a very, very small extent. Once in the bloodstream and after further processing of these nutrients, they are broken down into their constituent parts, namely carbohydrates to glucose, fats to fatty acids and protein to amino acids.
Most organs can use both glucose and fatty acids as energy sources, but unlike others, our brains rely almost entirely on glucose because fat cannot cross the blood-brain barrier. Because in reality there are a variety of factors that can lead to glucose deficiency (such as prolonged starvation due to lack of food), as a survival mechanism the brain has the ability to use another type of fuel – ketones.
The brain does not rely entirely on ketones and always uses a certain amount of glucose, because our body has the ability to synthesize it itself (through the process of gluconeogenesis, for example), even if no carbohydrates are taken. Instead of 100%, however, in such situations, glucose decreases significantly as a source of energy – to about 30-40%.
The process of creating ketones (ketogenesis) occurs in the liver and depends largely on the levels of glucose and insulin. Glucose and fatty acids are metabolized to acetyl coenzyme A (acetyl CoA). It in turn binds to the oxaloacetate molecule and enters the Krebs cycle to produce energy.
Pyruvate, which is a precursor of oxaloacetate, is synthesized through the process of glycolysis. If the levels of glucose and insulin in the blood are low, this also leads to a significantly reduced process of glycolysis. In this case, instead of oxaloacetate binding to acetyl CoA, it is used in the process of gluconeogenesis.
All this creates a situation in which if acetyl CoA does not bind to oxaloacetate, then instead of in the Krebs cycle, it is used for the production of ketone bodies. In short, if blood glucose levels are low enough, this allows the fat metabolism in the liver to shift to ketone production.
Why the ketogenic diet is popular
The ketogenic diet has become increasingly popular over the last 20 years and is currently one of the most common diets. The classic ketogenic diet was created in 1920. By this time, there were already some scientific papers showing a significant improvement in symptoms and a significant reduction in seizures in people with epilepsy who go through a period of complete starvation. Researchers at Myo Clinic, looking for a way to mimic as many of the body’s metabolic adaptations as possible in complete starvation, came up with a ketogenic diet.
In essence, this type of diet is one in which fat predominates in the diet and to a much lesser extent protein and carbohydrates. Over the years, the diet has undergone various changes and currently several variations can be found. The ketogenic diet in its original form was created for purely therapeutic purposes, as a possible solution in people in whom drug therapy does not give satisfactory results (refractory epilepsy). According to the available data, in almost 30% of epileptics the drugs do not work optimally.
Excluding the proven effectiveness of epileptics, the popularity of this type of diet today is based mainly on some claims that the ketogenic diet leads to more effective weight loss compared to other types of diets that contain more carbohydrates. However, this is not the case at all and we will discuss later in the article.
Varieties of ketosis and the most commonly used foods in this type of diet
Classic Ketogenic Diet (CKD)
In the classic ketogenic diet, between 80 and 90% of the nutrients for the day are in the form of fat, 10 to 15% is excreted for protein, and carbohydrates are only about 5%. For the acquisition of fat, the emphasis is on various oils, especially coconut, olive oil, nuts, oily fish and others. Protein is obtained through fatty meats and fish, and carbohydrates mainly from green leafy plant foods.
Because this type of diet is used primarily for therapeutic purposes, including in young children and newborns, hospitalization is often required so that the patient can be monitored by a team of specialists familiar with the details of this regimen. Strict control and monitoring of calories and food is required. Often the diet is started with one or two days of complete fasting. When used therapeutically, in most people the effectiveness of the diet begins to be noticed about 2-3 months after starting. Most patients stop this diet after about 2 years without recurrence of seizures.
Modified Atkins Diet (MAD)
The modified Atkins diet, also known as the Atkins diet or the Atkins diet, is one of the most common modifications of the efficiency. The reason for this is that this variation of the diet is also very highly therapeutic, but is much easier to follow, is not so restrictive and reduces some of the negatives of ketogenic nutrition, which we will mention below. In MAD, the percentage of fat in the diet is reduced to about 60-65%, protein increases to about 30-35%, and carbohydrates can reach 10%, depending on the weight of the next and its caloric intake
The most important thing is to reach and maintain a state of ketosis and therefore the intake of nutrients can be further adjusted. Atkins modification does not necessarily require strict control over the amount of food. In fact, MAD is a variation that is used very often as a means of losing weight. A diet in which a person is allowed to eat as much as he wants and lose weight in spite of everything. Of course, this is not true, but through such marketing the diet has gained high popularity.
Treatment with low glycemic index
The Low Glycemic Index Treatment (LGIT) modification is very similar in macro-nutrient distribution to MAD. This diet follows basically the same distribution (60-65%: 30-35%: 5-10% for fat: protein: carbohydrates), but here the serious attention is paid to the glycemic index of the foods consumed. In fact, the diet allows you to eat anything with a glycemic index below 50.
MCT ketogenic diet
Dietary fats can be classified according to the length of the fatty acid chain. MCT is an abbreviation for Medium-Chain Tryglicerides. Unlike long-chain, medium-chain is processed in a slightly different way, allowing it to be absorbed very quickly, to enter directly into the liver and to be metabolized to ketones. In this way, ketogenesis and ketone levels in the body are further stimulated, allowing more protein and carbohydrates to be included in the diet without significantly impeding ketogenesis.
Unlike other modifications, the implementation and recommendations for the MCT ketogenic diet vary according to different clinics and specialists. Carbohydrates are limited to about 5-10%, but fats can vary between 60 and 80% and protein between 15 and 30%. The most important thing about this modification is the high intake of medium-chain triglycerides. Recommendations vary, but between 30 and 60% of the total amount of fat for the day should be in the form of MCT.
As high intake of medium-chain triglycerides can lead to stomach upsets, their amount is adjusted mainly according to the tolerance of the next type of diet. The higher the percentage of fats in the form of medium-chain triglycerides, the better, and it is recommended that their intake be evenly distributed throughout the day. Intake can also be supported by dietary supplements containing medium-chain triglycerides.
For whom is the ketogenic diet (not) suitable?
Ketone levels in our body under normal conditions are extremely low and ketogenesis increases only in certain situations, such as prolonged fasting, eating very few carbohydrates and more fat, prolonged exercise (sports), but also in physiological diseases such as diabetes. type 1.
The levels of ketones in the body are considered to be:
normal, at values below 0.5-1 mM;
moderate, at values between 1 and 7-8 mM;
dangerously high, at values above 10 mM, in which case ketoacidosis also occurs.
Here we must mention one very important thing, namely the difference between ketosis and ketoacidosis, which many people confuse. Ketoacidosis is a life-threatening condition of extremely high levels of ketones in the body. Ketoacidosis can occur mainly in diseases such as type 1 diabetes, if the patient does not inject insulin in time. In more serious cases, ketone levels in the body can reach up to 25 mM. Another thing that can cause ketoacidosis is taking high doses of isopropyl alcohol, as well as abrupt cessation of alcohol after long-term abuse (alcoholic ketoacidosis).
Under normal circumstances, however, the body has everything it needs to control ketone levels and ketogenesis. In healthy people, insulin and glucose levels almost never fall so low that ketogenesis gets out of hand. Even after several days of complete starvation or adherence to the so-called ketogenic diet, which we will discuss below, ketone levels do not exceed 7-8 mM and this is not dangerous. A ketogenic diet may be helpful in certain diseases as an aid to their treatment.
Reduction of seizures in patients with epilepsy
Control of epileptic seizures is the main reason for creating and following this type of diet. The efficiency is indisputable and has been proven many times. Unfortunately, not all people have the same result, but most scientific data show that:
- in 50% of people seizures decrease by more than 50%;
- about 30% achieve up to 90% reduction;
- between 5 and 15% manage to get rid of it completely.
An aid in pyruvate dehydrogenase deficiency
Deficiency of the enzyme complex pyruvate dehydrogenase leads to a number of neurological complications and adherence to a ketogenic diet is among the main recommendations for dealing with the problem.
However, not everyone agrees.
An aid in GLUT-1 deficiency
Glucose transporter deficiency 1 is an inherited neurometabolic disease in which not enough glucose reaches the brain. This can lead to seizures and cognitive impairment. A ketogenic diet is a possible solution that can be tried , but some reported complications, such as high hypertriglyceridemia, should be considered.
There are few data, but a ketogenic diet has the potential to help deal with episodic or chronic migraines.
Aid to combat type 2 diabetes
A number of scientific studies have shown that following a low-carb diet helps reduce some important markers, such as blood sugar levels, glycated hemoglobin, triglycerides and some others. Although the “low-carb diet” covers a relatively wide range of carbohydrate amounts, much of the research is on a ketogenic diet.
An aid in the treatment of cancer
The ketogenic diet has been repeatedly studied for the prevention or treatment of various types of cancer. Unfortunately, as stated in the systematic review of English scientists from May 2017, at this stage the data are not enough and many more are needed for the ketogenic diet to be used therapeutically in this direction.
In most cases, the ketogenic diet does not pose a serious danger to health and life. The most common side effects and ailments are observed mainly in the classic version of the diet due to the total exclusion of certain food groups. Common and possible side effects are:
- Gastroesophageal reflux;
- Unexpected weight loss or gain;
- Increased hunger and appetite (mainly the first days until the body adapts to ketosis);
- Deficiency of some nutrients – calcium, selenium, zinc, copper, magnesium, vitamin D, B vitamins, l-carnitine;
- Increased risk of kidney stones;
- Change in lipid profile.
Although extremely rare, it is possible to reach a life-threatening condition of ketoacidosis. Among the scientific data there are 3 such reports. All three are for women, two of whom were breastfeeding (breastfeeding and pregnant women are at risk). The ketogenic diet in all its variations is contraindicated in people with specific diseases that disrupt fat metabolism, such as primary L-carnitine deficiency, deficiency of the enzymes carnitine palmitoyl-transferase, carnitine translocase or pyruvate carboxylase, as well as defects in the beta-oxy process.
Studies conducted by de Lima in 2015 and 2017 draw attention to the fact that in addition to changes in the values of the lipid profile in general, attention should be paid to the size of lipoprotein fractions and they should be monitored regularly.
What type of physical activity combination would be optimal?
With the commercialization of some variations of the ketogenic diet, this type of diet has been repeatedly recommended as a substitute for a diet of moderate or high carbohydrates, in order to improve athletic performance and performance. Although research on this topic is not small, the data are very contradictory and most of the research has many shortcomings. Only two of them have gone through a peer-reviewed process.
One of them, the participants in which are off-road cyclists, observed an improvement in the maximum oxygen flow (VO2 max) and oxygen flow at the lactate limit (VO2 LT) in the group following a ketogenic diet, but significantly better power results were observed in maximum intensity (power output) in the group receiving a normal amount of carbohydrates.
The other study was conducted with rhythmic gymnasts. There was no change in strength during the 30-day period of compliance. There is a slight improvement in body composition – weight loss and fat percentage.
Although the benefits of following a low-carbohydrate and ketogenic diet cannot yet be firmly denied, it is also not entirely clear what the specific circumstances in which this diet may be beneficial.
Most scientific data currently have some similar conclusions:
- adherence to a low-carb or ketogenic regimen can help improve body composition, mainly by reducing weight and excess fat, but is not optimal for gaining muscle mass;
- when seeking maximum and optimal sports performance, including aerobic and anaerobic sports activities, it is necessary to consume at least a moderate amount of carbohydrates.
What to expect in the long run when following a ketogenic diet?
The ketogenic diet and all its variations have gained immense popularity due to their marketing as a better and more effective diet for weight loss. In the last 15 years, the number of scientific papers examining the effectiveness of low-carbohydrate diets has not stopped growing. Many of them show and prove the effectiveness of the diet. Many compare this type of diet with a high-carbohydrate one and find better results. The problem with most such studies is that they have serious shortcomings
Most were not conducted in metabolic compartments, which means that they have almost no control over the participants and rely entirely on their judgment of what they ate and in what quantities. This assessment can vary greatly.
Unfortunately, the research conducted in metabolic wards is very small in number, as it requires extremely serious financial resources and there are serious difficulties in finding participants for long-term implementation. Few people want to live in a laboratory for more than 1 month.
Another problem encountered in this type of research is the lack of equalization of calories and the amount of protein that study participants receive. Both the amount of calories and the amount of protein have been repeatedly proven to be an important factor in weight loss.
If they are not aligned with the different participants, it cannot be concluded that low carbohydrates are the only reason for a better or worse result. If these research shortcomings are not taken into account when considering their results, the risk of drawing the wrong conclusion is very high.
However, there are also studies in which the methodology is at a very high level and we want to focus on them. One of these tests was conducted in the metabolic ward, and the others, although not, for each of the participants in them was prepared an individual diet, given exact recipes and instructions on how to prepare and monitor food. In one of them, the food was personally prepared by the organizers of the study.
We also present two meta-analyzes examining research with a high-level methodology.
The results can be summarized as follows: other things being equal, low-carb and ketogenic diets lead to just as effective weight loss as high-carb diets. The most important thing is to follow a regimen that is most convenient and tasty for the individual and he will be able to adhere to it in the long run.
Ketogenic nutrition, if well structured, can be a completely safe diet and does not prevent it from being followed for a long time, indefinitely. However, if you decide to eat this way, pay attention to the described risks it poses. Apart from the effectiveness in certain diseases, such as epilepsy, the main reason for following this type of diet should be mainly taste preferences.
Many people follow a ketogenic diet only because of the claims of higher efficiency in weight loss, but our advice is not to be misled and this is not the only reason to eat this way. If you decide to eat this way, we recommend that you avoid the classic diet and opt for a less restrictive modification, such as the Atkins modification.
Professional athletes and athletes who insist on maximum training and competitive performance are advised to switch to another type of diet that contains more carbohydrates.
Sources used :
- The Modified Atkins Diet
- Medium-chain triglyceride ketogenic diet, an effective treatment for drug-resistant epilepsy and a comparison with other ketogenic diets
- To treat or not to treat drug-refractory epilepsy by the ketogenic diet? That is the question
- The Ketogenic Diet: A Practical Guide for Pediatricians
- A blinded, crossover study of the efficacy of the ketogenic diet
- Efficacy of the ketogenic diet as a treatment option for epilepsy: meta-analysis
- Therapeutic Success of the Ketogenic Diet as a Treatment Option for Epilepsy: a Meta-analysis
- Efficacy of and patient compliance with a ketogenic diet in adults with intractable epilepsy: a meta-analysis
- Low glycemic index treatment in patients with drug-resistant epilepsy
- Ketone Bodies as a Possible Adjuvant to Ketogenic Diet in PDHc Deficiency but Not in GLUT1 Deficiency
- Role of ketogenic metabolic therapy in malignant glioma: A systematic review
- Ketogenic Diet and Cancer-a Perspective
- Effects of Pre-surgical Vitamin D Supplementation and Ketogenic Diet in a Patient with Recurrent Breast Cancer
- Starvation of cancer via induced ketogenesis and severe hypoglycemia
- Metabolic therapy: a new paradigm for managing malignant brain cancer
- The ketogenic diet for the treatment of malignant glioma
- Counseling patients on cancer diets: a review of the literature and recommendations for clinical practice
- Restricted calorie ketogenic diet for the treatment of glioblastoma multiforme
- Selectively starving cancer cells through dietary manipulation: methods and clinical implications
- Calorie or Carbohydrate Restriction? The Ketogenic Diet as Another Option for Supportive Cancer Treatment
- Ketone body utilization drives tumor growth and metastasis
- Metabolic management of brain cancer
- Low-carbohydrate diets and prostate cancer: how low is “low enough”?
- Targeting energy metabolism in brain cancer through calorie restriction and the ketogenic diet
- Systematic review: isocaloric ketogenic dietary regimes for cancer patients
- Energy substrate metabolism in pyruvate dehydrogenase complex deficiency
- The Effects of Ketogenic Diet on Seizures, Cognitive Functions, and Other Neurological Disorders in Classical Phenotype of Glucose Transporter 1 Deficiency Syndrome
- New Paradigm for the Treatment of Glucose Transporter 1 Deficiency Syndrome: Low Glycemic Index Diet and Modified High Amylopectin Cornstarch
- Ketogenic diets in patients with inherited metabolic disorders
- Reversible white matter lesions during ketogenic diet therapy in glucose transporter 1 deficiency syndrome
- Towards a more palatable treatment for Glut1 deficiency syndrome
- Symptomatic west syndrome secondary to glucose transporter-1(GLUT1) deficiency with complete response to 4:1 ketogenic diet
- Severe Hypertriglyceridemia in Glut1D on Ketogenic Diet
- The Ketogenic Diet: Uses in Epilepsy and Other Neurologic Illnesses
- Ketogenic diet in migraine: rationale, findings and perspectives
- Use of the modified Atkins diet for adolescents with chronic daily headache
- Restricted-carbohydrate diets in patients with type 2 diabetes: a meta-analysis
- Effects of low carbohydrate diets on weight and glycemic control among type 2 diabetes individuals: a systemic review of RCT greater than 12 weeks
- Middle and Long-Term Impact of a Very Low-Carbohydrate Ketogenic Diet on Cardiometabolic Factors: A Multi-Center, Cross-Sectional, Clinical Study
- Dietary carbohydrate restriction as the first approach in diabetes management: critical review and evidence base
- Treatment of diabetes and diabetic complications with a ketogenic diet
- Effect of low-calorie versus low-carbohydrate ketogenic diet in type 2 diabetes
- Effect of the LoBAG30 diet on blood glucose control in people with type 2 diabetes
- Optimal clinical management of children receiving the ketogenic diet: Recommendations of the International Ketogenic Diet Study Group
- Long-term use of the ketogenic diet in the treatment of epilepsy
- Ketoacidosis associated with low-carbohydrate diet in a non-diabetic lactating woman: a case report
- Severe ketoacidosis in breastfeeding woman with low energy and carbohydrate intake.
- Ketoacidosis associated with low-carbohydrate diet in a non-diabetic lactating woman: a case report
- Ketoacidosis during a Low-Carbohydrate Diet
- Ketogenic diet in epileptic children: impact on lipoproteins and oxidative stress
- Effect of classic ketogenic diet treatment on lipoprotein subfractions in children and adolescents with refractory epilepsy
- The Effects of a Ketogenic Diet on Exercise Metabolism and Physical Performance in Off-Road Cyclists
- Ketogenic diet does not affect strength performance in elite artistic gymnasts
- Ketogenic diets and physical performance
- The human metabolic response to chronic ketosis without caloric restriction: Preservation of submaximal exercise capability with reduced carbohydrate oxidation
- Enhanced endurance in trained cyclists during moderate intensity exercise following 2 weeks adaptation to a high fat diet
- Interaction of training and diet on metabolism and endurance during exercise in man
- Endurance capacity and high-intensity exercise performance responses to a high fat diet
- Metabolic characteristics of keto-adapted ultra-endurance runners
- Capacity for moderate exercise in obese subjects after adaptation to a hypocaloric, ketogenic diet
- Ketogenic Diets for Fat Loss and Exercise Performance: Benefits and Safety?
- Re-Examining High-Fat Diets for Sports Performance: Did We Call the ‘Nail in the Coffin’ Too Soon?
- Fat-Free Mass Changes During Ketogenic Diets and the Potential Role of Resistance Training
- Effects of Short-Term Carbohydrate Restrictive and Conventional Hypoenergetic Diets and Resistance Training on Strength Gains and Muscle Thickness
- Energy expenditure and body composition changes after an isocaloric ketogenic diet in overweight and obese men
- Ketogenic low-carbohydrate diets have no metabolic advantage over nonketogenic low-carbohydrate diets
- Relatively high-protein or ‘low-carb’ energy-restricted diets for body weight loss and body weight maintenance?
- A Randomized Trial Comparing Low-Fat and Low-Carbohydrate Diets Matched for Energy and Protein
- Long-term effects of very low-carbohydrate and high-carbohydrate weight-loss diets on psychological health in obese adults with type 2 diabetes: randomized controlled trial
- Low Carbohydrate versus Isoenergetic Balanced Diets for Reducing Weight and Cardiovascular Risk: A Systematic Review and Meta-Analysis
- Comparison of Weight Loss Among Named Diet Programs in Overweight and Obese Adults
- Ketone bodies in epilepsy
- Long-term follow-up of children treated with the modified Atkins diet
- Ketone bodies as a fuel for the brain during starvation