What is a Ketogenic Diet?
The Ketogenic Diet (KD) is typically lower in carbohydrates and higher in fats. However, as you read in our “What is a ketogenic Diet?” article, it is much more than that. Once the body adapts to a KD, it switches from primarily using glucose as fuel, to using fat/ketones. This adaptation within the body, to increase fat breakdown and oxidation, can aid in improved body composition, general health, performance, and perhaps even longevity!
Low Carbohydrate vs. ketogenic Diet
While a KD is also low in carbohydrates, it is NOT synonymous with traditional low carbohydrate diets, in which the amount of carbohydrate and protein intake differs (usually both are higher in general “low carb diets”). In research, a low carbohydrate diet may be classified as any diet in which less than 30% of the total daily macronutrient calories come from carbohydrates. While these diets may be beneficial, it must be reinforced that they DIFFER from a well-formulated KD. In general, the macronutrient ratio for a KD consists of about 5-10% carbohydrates, 15-30% protein, and the remaining as fat. By restricting glucogenic substrates (i.e. nutrients that increase blood glucose levels, like carbohydrates), a deeper level of ketosis can be achieved, which may have a plethora of benefits as discussed below. As an example, this study comparing 30, 60, and 100 grams of carbohydrates found that restricting carbohydrates to 30 grams led to a greater increase in circulating ketone levels (1).
Traditional Atkins vs. Ketogenic Diet
The Atkins diet and KD are often used synonymously; however, they are different. While both diets lower carbohydrate consumption, the Atkins diet allows for a period in which both protein and carbohydrate intakes are increased (while fat intake is lowered) beyond what would classify as ketogenic. The goal of the KD is to shift the body into utilizing fat/ketones as its primary fuel source. By doing so, the body creates a metabolic substrate called ketone bodies. However, due to the increase of both carbohydrates and protein, and lower intake of fat, the Atkins diet often does not result in a consistent state of ketosis, and therefore is metabolically different from a KD.
In addition to the traditional ketogenic and Atkins diets described above, there are modifications that can be implemented to both of these diets in order to produce greater benefits on an individual basis. One such amendment, called the Modified Atkins Diet (MAD), is structured similarly to the Atkins diet, so that carbohydrates are monitored while the other two macronutrients (protein and fat) are consumed freely. This approach is commonly being used in children with epilepsy with great success, due to its ability to increase the likelihood of adherence to the diet while still minimizing glucose intake in the form of dietary carbohydrates (2).
There exists great debate on how to quantify the macronutrient ratios for a traditional KD. Despite the numerous opinions, one must keep in mind that the ultimate objective is to develop a diet that is sustainable in achieving the desired outcome (i.e., a state of ketosis). As such, while it is suggested that 65-80% of the total calories come from fat, and 15-30% from protein, these numbers will be optimized according to every individual’s unique metabolic needs. For example, an individual who is trying to achieve a state of ketosis might have different macronutrient ratio requirements than someone who is using the KD to improve their body composition. Once the body begins to use fat as its primary fuel source, metabolic “keto-adaptation” accompanied by increased production of ketones occurs, which is further described below. It must be reinforced that there is no set optimal level of ketosis nor standard macronutrient profile since factors such as activity level and the desired outcome will influence these variables. Although individualized, Ketogenic.com currently recommends that active individuals beginning the diet use a similar macronutrient ratio (based on total calorie intake).
For example, if you are consuming 2,000 calories per day, that would equate to 155 grams of fat, 125 grams of protein, and 25 grams of carbohydrates. Keep in mind that these ratios may change if you are inactive (i.e., 15-20% protein).
Benefits of the Ketogenic Diet
Restricting carbohydrates can provide many different health benefits. Due to the higher level of ketone production accompanied with a KD, the majority of the benefits listed below are typically more robust when compared to a general low carbohydrate diet:
- – Increased Energy: Both fat and ketone bodies can be utilized as a fuel source for the body. Once the body begins to use fat and ketones as its primary fuel source, there will be a noticeable increase in energy.
- – Cognitive Enhancement: Ketones may be the preferred fuel source of the brain as well as cardiac tissue. Due to tissue preference, upon ketone production, it is very common for individuals to report an increase in cognitive performance.
Appetite Control: The high-fat nature of the KD, as well as stable blood glucose levels due to carbohydrate restriction, have been shown to have a profound effect on appetite. Thus, this may give individuals who have a hard time controlling how much food they eat “freedom” in knowing that they won’t be as hungry and thus less likely to consume excess calories.
- – Being in a state of ketosis can suppress the hunger hormones that are typically increased during traditional “dieting” (3).
- – Additional research has shown that eating dietary fat can suppress the hormones responsible for appetite stimulation (4).
- – Participants on a KD with unrestricted caloric intake consumed fewer calories throughout the day and felt more satiated than those on a similar unrestricted low-fat diet (5).
Physical changes in the body are one of the primary reasons people are attracted to and implement low carbohydrate diets. By definition, being in a state of ketosis means you are able to tap into the body’s fat stores, meaning you can break them down to be used as energy, or to produce ketones that can then be used as energy. Furthermore, the KD has been shown to reduce circulating insulin levels, which may lead to less storage of fat by the hormone insulin (6). While both “low carbohydrate” and KD are effective for weight loss, studies have demonstrated that the KD is superior (1).
Other Key Points:
- – Ketogenic and low carbohydrate diets have been shown to decrease body fat percentage to a greater extent than low-fat diets (7).
- – Research has found that the greater the carbohydrate restriction, the greater the percentage of fat loss (8, 1).
- – Research has shown that ketones have anti-catabolic properties for muscle-tissue (9).
- – Some studies have even supported an increase in muscle mass when the KD is coupled with exercise (10, 11).
Endurance Performance: Traditionally, endurance athletes tend to consume a high amount of carbohydrates in order to “fill up” their fuel stores for competitions. Thus, a diet where carbohydrates are restricted seems counter-intuitive for these individuals. However, Dr. Jeff Volek showed that once an individual is keto-adapted, not only is their performance the same or better than those consuming high levels of carbohydrates but their glycogen “fuel stores” are the same as well (12). Despite consuming a diet lower in carbohydrates, these athletes are able to adapt and utilize a nearly limitless supply of fat as their primary fuel source (and at a faster rate, allowing for fat utilization at higher intensities).
- – Therapeutics: The KD was developed in the 1920s as an alternative therapeutic option to treat children suffering from drug-resistant epilepsy. Since its inception, the utilization of the KD has expanded as a therapeutic treatment for many other conditions such as Alzheimer’s disease, Parkinson’s disease, GLUT-1 deficiency, and even cancer. While low carbohydrate diets collectively offer therapeutic benefits, there are additional potent benefits from the application of a traditional KD, due to the unique nature of its ability to increase ketone production in the body.
Is the Ketogenic Diet Safe?
Quite simply the answer is an astounding “yes!” for the majority of people. Due to its high-fat nature, it is often perceived as a health risk, and therefore, often deters individuals from trying it. Despite this misconception, research has demonstrated that the KD is safe for most people, providing you don’t have one of the following conditions (keep in mind that even if you are experiencing any of these, the KD may still be safe, but you would need to work very closely with your doctor):
Isn’t Fat Bad?
Unfortunately, it has been ingrained into society that consuming dietary fat is detrimental to our health. Due to early “research” by individuals such as Ancel Keys, these concepts have plagued us for several decades and have only recently changed our perceptions of dietary fat. Dietary fat, when consumed alone, isn’t the culprit for bad health, but rather the pairing of fat and carbohydrates in meals (i.e., fast food). This high-fat-carb duo has led to the many serious problems we face today. This gives rise to the quote, “Don’t blame the butter for what the bread did.”
What is Ketosis?
Ketosis is a metabolic state that is characterized by elevated blood ketone levels coupled with lower, stable blood sugar levels. When dietary carbohydrate is broken down into the energy substrate glucose, this raises blood glucose levels, which stimulate the pancreas to secrete insulin (the hormone that stores fat and inhibits ketone production.) However, when carbohydrate intake is restricted, insulin is low, and the body’s primary fuel source shifts from glucose to fat, which primes the body to enter a state of “ketosis.” Ketones are made in the liver through a process known as ketogenesis (i.e., keto + genesis = ketone formation.) When carbohydrate intake is restricted, blood glucose and insulin levels decrease, which allows fat stores to break down and provide energy. Once our metabolism is primed for fat burning (fatty acid oxidation), the liver will produce additional fuel molecules known as ketones. Most cells in the body can utilize either fatty acids or ketones for fuel, including the brain which seems to prefer ketones over glucose.
Ketosis vs. Ketoacidosis
The confusion between ketosis and ketoacidosis is a prominent reason why many individuals steer clear of the KD. Let’s start by saying they are two COMPLETELY DIFFERENT metabolic states. Ketoacidosis may occur in Type 1 diabetics (DKA; diabetic ketoacidosis) due to insulin deficiencies. DKA is associated with both elevated blood glucose and ketone levels; due to insulin deficiency, blood glucose cannot enter insulin-dependent cells to be used for energy, and as such, cells become hungry, resulting in uncontrolled ketone production. In turn, a highly acidic environment is created and can have detrimental effects on an individual’s health, including death. It must be echoed that the KD, which induces “nutritional” ketosis, is vastly different and should never be confused with DKA. To put this in perspective, a normal state of ketosis, as achieved via the KD, may elevate ketones anywhere from .3-5mM, while DKA results in ketone levels of about 15mM or higher.
Where Do Ketones Go?
Glucose is the primary fuel source for most tissues throughout the body. However, once “keto-adapted,” many tissues increase their capacity to take up and utilize ketones for fuel. Some tissues even prefer to use ketones for their cellular energy needs. For instance, the heart, as well as many areas of the brain, prefer to use ketone bodies as opposed to glucose. In contrast, there are certain cells that cannot use fatty acids or ketone bodies, and are considered “obligate glucose users.” Red blood cells and specific parts of the brain are obligate glucose users. Don’t stress, however, because even though you may not be consuming carbohydrates, these cells can obtain glucose through a biological process called gluconeogenesis (the production of glucose from other non-glucose materials).
Dr. Stephen Cunnane found that the uptake of ketone bodies in the brain is proportional to their production (13). Additional research has also demonstrated that as uptake of ketones increases, the uptake of glucose decreases in brain tissue (14, 15). Due to the highly important energy demands of the brain, the liver will partially break down fatty acids and convert those into ketone bodies, which are then used to supply the energy demands of the brain.
How Long Does It Take to Get into Ketosis?
The answer to this question is often individualized and will depend on the metabolic state of each individual. One can enter a state of ketosis after an overnight fast. However, this slight elevation may not be high enough to allow for your body to efficiently utilize these ketones as a primary fuel source. Over time, as you become more adapted, your body will consistently be producing AND utilizing ketones. For some, this could take as little as one week, however, for others, it could take several weeks to accomplish.
Keto-adaptation occurs as tissues maximally increase their capacity to utilize ketone bodies for fuel. It requires a metabolic shift from primarily using glucose for energy, to using fatty acids. As glucose metabolism slows and fatty acid breakdown ramps up, ketones become synthesized and increasingly utilized for fuel. After a few weeks or months of increasing ketone and fat utilization, the body adapts to these new fuel sources, and you will become more keto-adapted. In addition to increased fat breakdown and ketone synthesis and utilization, keto-adaptation is associated with decreased and stabilized blood glucose levels. Imagine building up “tunnels” on the borders of the tissues in your body. As you continuously build up these tunnels/transporters, you will be able to take up and utilize ketones better
The length of time it takes to become keto-adapted is individualized and depends on the composition of the KD utilized (i.e., 20 grams versus 40 grams of carbohydrates per day), as well as personal activity level.
Among the many biological modifications that must occur for sufficient ketone body utilization, the upregulation of ketone transporters must take place. Thus, research has demonstrated that chronic elevations in blood ketone levels positively increase the number of these transporters. Therefore adherence, especially during the initial stages of the KD, is critical.
Side Effects of Keto-Adaptation
Despite the therapeutic benefits of a KD, some individuals may experience side-effects during the initial “keto-adaptation” process. Again, this will vary depending on the individual. The set of common side-effects associated with keto-adaptation have been collectively been coined the “keto-flu.”
“Keto-flu” as outlined below:
The “keto-flu” is a term used to define the period of discomfort that accompanies the biological changes that occur when switching the body’s primary fuel source from carbohydrates to fats. With symptoms that often feel like an illness, the “keto-flu” may be characterized by the symptoms below:
As mentioned above, if the KD has been well-formulated, many of these symptoms may not occur or can be alleviated through proper electrolyte supplementation.
In addition to the “keto-flu,” many individuals may also experience impaired physical performance as the body adapts to the shift in fuel sources; however, this is only temporary and performance should be back up to speed upon full adaptation. As such, decreased performance may be expressed as:
- – Lack of motivation to exercise
- – Decreased endurance
- – Lack of strength
- – Fatigue
Research looking at performance measures following the first 6 days of a KD have found that performance suffers (16). However, Paoli found that after a month of ketogenic dieting, performance did not suffer (17).
Rapid Weight Loss
At the start of a KD, it is not uncommon for an individual to experience rapid weight loss. This may concern some people, but it is worth noting that not ALL weight lost is body fat. When we lower our carbohydrate intake our insulin lowers, and when our insulin lowers we tend to excrete more water. Additionally, reducing carbohydrate intake causes the body to break down glycogen stores (to initially maintain blood sugar levels); glycogen is the storage form of glucose that is located in our liver and skeletal muscle. The loss of both water and glycogen accounts for most of the weight loss in the first few days. But don’t be discouraged! Increased fat burning immediately follows glycogen depletion!
Troubleshooting Your Keto Side Effects
- – Cravings
As one begins to eliminate carbohydrates from the diet, it is common to experience carbohydrate cravings. Several suggestions for conquering these cravings are outlined below. However, it should be noted that as the body keto-adapts, hunger and appetite should become suppressed.
- – Add more volume through increased consumption of high-fiber vegetables
- – Increase water consumption
- – Increase fat consumption
- – If you are experiencing sugar cravings, try making a keto dessert from our recipe section!
- – Increase fat consumption
- – Empty the home of all sugary sweets before starting a KD
- – Have alternative KD approved options prepared and readily available
One interesting study found that a balloon entered into the stomachs of subjects led to feelings of perceived fullness (18). This means by doing things like drinking more water we can improve our feeling of fullness.
Headaches can be a common symptom of the “keto-flu.” Outlined below are several options to help alleviate the symptoms:
- – Drink more water
- – Replenish electrolytes
- – Take a short nap
- – Eat more fat/Medium Chain Triglycerides (MCTs)
Due to the initial release of water when starting a KD, dehydration is another symptom commonly experienced, and may be responsible for potential “dry mouth.’ An effective remedy is to ensure that there is sufficient consumption of water coupled with electrolyte balance (particularly magnesium). If dehydration persists, an increase in electrolytes may be needed.
In order to cope with this symptom, several options below may be consumed during this “adaptation” phase:
- – Medium Chain Triglycerides (MCTs)
- – Caffeine
- – Electrolytes
- – Exogenous Ketones
As mentioned above, the elimination of carbohydrates coupled with the increased release of water may lead to constipation. If this occurs, simply increasing water consumption as well as incorporating more fiber into the diet can alleviate these symptoms.
Are There Different Types of Ketosis?
There are several different methods in which the body can enter the metabolic state of ketosis.
1. Fasting ketosis:
Fasting ketosis, also referred to as starvation ketosis, played a major role in the development of the KD. The concept of fasting has been around for centuries and can be traced back to biblical times. By definition, fasting is the absence of food consumption for a period of time. This can range from several hours to several days and can have profound effects on the degree of ketosis. As the duration of the fasting increases, so does the production of ketones, and thus, a deeper ketogenic state. As such, the mechanisms of ketone production are similar among fasting and dietary applications in which both result in lower and more stable levels of insulin and blood glucose accompanied by fat metabolism.
A monumental study by George Cahill found that as fasting time increases, the level of ketone production also increases, and will eventually stabilize (19). Spanning for a period of 40 days, this landmark study is a prime example of the safety of the KD for a majority of individuals.
2. Nutritional ketosis:
Nutritional ketosis is classified as any dietary application that elicits the metabolic state of ketosis via ingestion of food, supplements, or beverages. There are 3 sub-types of nutritional ketosis:
Carbohydrate-Restricted Ketosis– This type of ketosis mimics the same biological alterations seen during lengthy fasts, but without the complete restriction of food. Carbohydrate-restricted ketosis is achieved primarily through a very low carbohydrate KD. This restriction, in turn, promotes reductions in insulin and blood glucose levels similar to that of fasting, which again increases blood ketone levels. For most individuals, nutritional ketosis is much more sustainable than fasting or starvation ketosis.
Tip: Fasting can still have its place in a KD. Many individuals following a KD like to implement a regular fasting protocol such as intermittent fasting (IF). This practice is not critical for success on a KD, but it can enhance the level of ketone production, and thus, magnify the benefits.
Supplemental ketosis: This form of ketosis has recently gained momentum in the field of ketogenic dieting. Supplemental ketosis is a ketogenic state that is achieved through the ingestion of ketogenic supplements. The commonly used supplements on the market are:
– Medium Chain Triglyceride (MCT) Oil: MCT oil is a fat that, in contrast to other longer-chain fatty acids, travels straight from the intestines to the liver, and is readily metabolized. This, in turn, allows for ketone production in the liver to occur faster than with other fats (long-chain fatty acids have to travel through the lymph and circulatory systems first).
– Exogenous Ketones: Exogenous ketones are synthetic substances that mimic the ketones produced in our body (endogenous ketones). Exogenous ketones can come in the form of ketone salts or ketone esters.
It is very important to note that consuming these substances alone does not mean that an individual is “keto-adapted.” While these products can help during the keto-adaptation period, especially if one is experiencing the “keto-flu,” they will only elicit short-term increases in blood ketone levels. Exogenous ketones can acutely produce benefits similar to the KD; however, these products are best used in conjunction with a well-formulated KD, or the very at least, a diet that restricts carbohydrates.
Alcoholic Ketoacidosis (AKA): Is a ketone producing state that may occur following excessive alcohol consumption for long periods of time. When alcohol is metabolized in the liver, ketones are produced. Furthermore, as with other ketogenic states, certain biological changes, specifically at the hormonal level, occur to promote fat metabolism and thus, ketone production. It is critical to note that AKA will not occur if the alcohol consumption is coupled with sugar.
Note: Ketogenic.com does NOT recommend or promote the consumption of alcohol to produce or augment a ketogenic state.
3. Diabetic Ketoacidosis
Diabetic ketoacidosis (DKA) is the variation of ketosis that is responsible for deterring society from considering the adoption of a KD. DKA occurs primarily in those suffering from Type 1 diabetes. The inability to secrete insulin prevents ingested carbohydrates (glucose) from entering our insulin-dependent cells (i.e., muscle and adipose tissue) as a substrate for energy production. Due to this induced cellular starvation, the body will begin to produce ketones at an uncontrolled rate. Detrimentally, this results in high levels of both ketones and glucose. Extremely high ketone levels in the blood will elicit a dangerous biological environment that can even result in death. It must be clarified that DKA is very different than nutritional ketosis or fasting ketosis; ketone levels cannot be produced at such high levels in healthy individuals, as with DKA.
How Do I Know If I am in Ketosis?
In order to maximize the benefits of a KD, self-experimentation to achieve an optimal level of ketosis is important. In addition to quantifying blood ketone levels, there are several biological changes that your body will experience to help identify a ketogenic state. These changes will be more robust for some; however, in contrast to the negative side effects often experienced while on other low carbohydrate diets, a ketogenic state, and especially “keto-adaptation” can elicit euphoric effects including:
- – Increased energy
- – Mental clarity
- – Increased cognitive performance
Testing Your Ketones
To determine whether or not you are in ketosis, there are several methods of measuring ketone levels, as noted below:
- Urine Strips:
When tested in urine, these strips will elicit a color change based on the level of ketones, namely acetoacetate, which is present in the urine. It is important to note that acetoacetate is different than the ketones present in the blood, namely, beta-hydroxybutyrate (βHB). Due to its nature, urine ketone testing may be a sufficient initial method to test ketone production; however, it is not the ideal method for determining the utilization of these ketone bodies, especially once “keto-adapted.”
- Blood Ketone Meter:
Measuring ketone levels in the blood more accurately measures and indicates an individual’s metabolic state of ketosis. Similar to measuring blood glucose levels, this method also uses a blood meter and a chemo-sensitive strip made specifically to measure ketones (βHB). As with blood glucose measurements, a blood sample can be acquired from a finger prick. The ketone level displays on the meter within a few seconds of a sample placement on the strip.
- Breath Ketone Analysis:
This method analyzes an individual’s breath to determine whether or not they are producing ketones, specifically, acetone. While this method has also been found to be an effective indicator, more research needs to be done to examine how this compares to the blood testing. Studies investigating breath analyzers have found that these devices serve as a reliable indicator of ketosis (20).
Optimal Ketone Range
As with other facets of the KD, the optimal ketone levels will vary on an individual basis. However, literature typically suggests that mild nutritional ketosis will begin once blood ketones are around 0.3 – 0.5 mmol/L. Upon “keto-adaptation,” this value may increase to around 1.0-3.0 mmol/L; however, that’s not necessarily the case. If an individual is following a KD strictly for therapeutic reasons, one may consider trying to achieve a deeper level of ketosis, but even those that are strict may see only slight elevations in ketones due to rapid uptake into tissues.
Testing ketones may be a good way to initially determine one’s metabolic state of ketosis; however, as mentioned above, since the “optimal” level of ketones varies among individuals, daily ketone testing is not necessary.
How Do I Start?
There are several strategies for transitioning into a ketogenic state. Depending on a variety of factors and lifestyle habits, some individuals choose to ease into the process by adopting a low carbohydrate diet prior to implementing a full KD. One place to start would be to eliminate sugary, processed foods, and replace those with whole, lower-carbohydrate foods. In doing so, you will begin to understand the KD, and once ready you can dive into the diet and customize to you. To aid in the transition of a ketogenic lifestyle, our “Keto for You” is an excellent resource!
How Do I Eat?
As mentioned above, learning which foods promote a ketogenic state may be the most difficult and time-consuming task for most individuals adopting a KD. Below you will find several steps that may aid in this process. It should be noted that it is critical to eliminate sugar or any fast-digesting carbohydrates. These include, but are not limited to: cookies, chocolate, cakes, crackers, ice cream, cereal, pretzels, pastries, baked goods, fruit juice, soft drinks, honey, candy, chips, bread, and white potatoes.
1. Cut the “healthy” carbs: Even the carbohydrate-containing foods that are considered to be healthy should be eliminated on a KD, including but not limited to: fruit, rice, pasta, quinoa, sweet potatoes, yogurt, whole grain products, granola, oatmeal, and sports drinks.
2. Stick to high-quality protein, fatty cuts of meat, healthy fats, and high-fiber cruciferous vegetables, while also drinking plenty of water. These are staples of a KD.
Note: When shopping, become accustomed to reading nutrition labels, paying careful attention to “sneaky carbohydrates” that may be included in dressings, sauces, and dips, which can add up quickly and knock individuals out of ketosis.
Common Ketogenic Dieting Mistakes:
As one embarks on a ketogenic lifestyle, there are major changes that need to occur aside from the biological adaptations in which there does exist a learning curve. Below are common mistakes that individuals can make when adopting a KD.
1. Not having enough fat: People restrict their carbohydrates but fail to increase their fat intake.
2. Having too much protein: This may not be an issue for everyone, but for others having too much protein can negatively impact ketosis, due to its glucogenic effects. The level needed to achieve this is still unknown, but likely higher than we originally thought. To prevent this, try to eat whole foods as much as possible instead of isolated protein sources (i.e., straight protein shakes).
3. Too many “sneaky carbohydrates”: Those who do not track may end up exceeding the 20-50g, or around 5-10%, which is traditionally recommended.
4. Drinking too much alcohol: Certain alcohols may be tolerated in moderation by individuals while remaining in a ketogenic state. However, consuming too many alcoholic beverages, which are often high in carbohydrates, can prevent some from achieving a ketogenic state, or will knock one out of ketosis if the ketogenic state has already been achieved.
A Well-Formulated Ketogenic Diet:
When adopting a KD, ensuring that it has been “well-formulated” is indispensable. Unfortunately, this critical factor is often overlooked and makes adherence to this diet very difficult. In addition, taking into consideration food quality and micronutrients are also just as critical. A well-formulated KD will also aid in the prevention or alleviation of the side effects/ “keto-flu” that are often experienced with the keto-adaptation process. To help create a well-formulated KD, some points of consideration are outlined below:
1. Fiber- Adequate fiber ensures that you have proper digestive function, and may aid in the prevention of constipation.
2. Water- As mentioned above, water loss can be rapid on a KD. To prevent dehydration, consumption of more water than one is accustomed to will be necessary. If an individual experiences lightheadedness, brain fog, constipation, or headaches, dehydration may be the culprit.
3. Electrolytes- Due to the increased water expulsion by the kidneys, many electrolytes are simultaneously lost. Electrolyte imbalances are heavily responsible for feeling the “keto-flu.” Important electrolytes one must consider replacing: Sodium, Potassium, and Magnesium. These electrolytes can be replenished by increasing your intake of certain foods and/or supplementation.
Here is our user-friendly, step-by-step guide to creating a ketogenic meal:
1. Choose A Protein Source
Choose a protein source of preference. Typically, it’s easier to choose a fattier protein source such as red meat, eggs, salmon, or chicken thighs. However, leaner meats will likely still work, fat will just have to be added elsewhere.
2. Add a High-Fiber Vegetable(s)
Selection preference is given to cruciferous, dark leafy greens. Salads following the suggested criteria for a well-formulated KD are always an excellent option.
3. Top with Fat
It is imperative that individuals on a KD consume an adequate amount of fat. This macronutrient can be achieved through the incorporation of full-fat salad dressings, butter, or oils (e.g., coconut, olive oil), full-fat cheeses and lower carbohydrate nuts.
Snacking on a Ketogenic Diet:
Snacking on a KD is not a requirement but a personal choice made on a daily basis. Some easy, low carb snacks on the go if hunger arises are:
- -String cheese
- -Pork rinds
- -Hard-boiled eggs
- -Nuts and seeds
- -Dehydrated meats/jerky
The adoption of a KD does not mean that the foods need to be boring. Many comfort foods may be modified to accommodate a ketogenic macronutrient profile. Below are some suggestions:
Breakfast- Egg frittata, egg and veggie cups, breakfast pizza, egg stuffed avocados
- Lunch- Portobello pizza, bell pepper nachos, shredded chicken chili
- Snack- Parmesan crisps, buffalo chicken stuffed celery, cream cheese balls
- Dinner- Cheesy meatball bake, meatloaf cupcakes, spinach and artichoke stuffed portobello mushrooms
- Dessert- Fat bombs, cheesecake, Ry’s peanut butter cup
Tips for Dining Out:
Using the tips below, maintaining a ketogenic lifestyle while dining out can be stress-free.
1. Assess the menu options ahead of time.
2. Ask questions! Ask your server how specific dishes are prepared (sauces, dressings, seasonings, etc.).
3. Avoid the bread basket.
4. When in doubt, keep it simple by ordering a meat of choice with veggies/side salad. Top with a full-fat dressing, butter, or oils.
Supplements on a Ketogenic Diet:
To reiterate, maintaining electrolyte balances is critical on a KD, in order to prevent side-effects and the “keto-flu.” While this can be done exclusively through whole foods, some individuals may require additional sources. Sodium, magnesium, and potassium can all be replenished via supplementation.
Caffeine can be a useful supplement during the “keto-adaptation” process, as lethargy is a common side effect.
Medium Chain Triglyceride (MCT) Oil:
As the primary fat composition in coconut oil, and due to its bio-availability, MCT oil can contribute to ketone production while serving as a reliable energy source.
As with electrolytes, fiber can be acquired exclusively through food. For those individuals who do not prefer eating a lot of vegetables, a fiber supplement can be considered.
Vitamin D can be supplemented but is also found in many foods allowed on a KD, including fatty fish, beef liver, cheese, and egg yolks.
To ensure micronutrient levels are sufficient and balanced, some individuals may consider incorporating a green supplement; however, it is critical that the supplement is low in carbohydrates.
Fish oil is an excellent addition to any healthy diet, especially a diet that is lacking in Omega-3 fatty acids. Research investigating the effects of fish oil supplementation on a KD demonstrated greater reductions in triglyceride levels when compared to a KD without supplementation (21).
Supplemental, or exogenous ketones, are gaining momentum in the ketogenic community. As such, it has piqued the interest of those curious about the ketogenic lifestyle. Exogenous ketones are synthetic ketones that, upon ingestion, can increase blood ketone levels. Exogenous ketones come in both powder and liquid form:
- – Ketone Salts
- – Ketone Esters
It is important to note that consuming these supplements does not mean that an individual is “keto-adapted.” While these products can acutely put one’s body into a state of ketosis, which may alleviate “keto-flu” symptoms for some, most individuals use ketone supplements in conjunction with a ketogenic or low carbohydrate diet.
Tip: Consuming a moderate dose of exogenous ketones during the initial “keto-adaptation” period could potentially accelerate the “adaptation,” while at a minimum increasing energy production. Once one is adapted, these products are excellent for achieving higher blood-ketone levels, which, in turn, can be beneficial for athletic and cognitive performance, energy production, and perhaps more effective therapeutic treatment.
Ketogenic Diet for Therapeutic Applications:
Blood Lipids on a KD:
Lack of proper education has incorrectly held a high-fat diet responsible for an increase in blood lipids. Decades of research, combined with efforts to shift the paradigm, are now revealing that increased dietary fat consumption does not directly result in increased blood lipids. It is actually carbohydrate consumption that tends to increase total cholesterol with noticeable decreases in the HDL “good” cholesterol. Also, often times researchers use a “high-fat diet” interchangeably with a “Western diet”; many confuse the term “high-fat diet” in the research with a KD. A “high-fat diet” in the research indicates a diet with both high-fats and high-carbs, which is associated with increased blood lipids, whereas a KD is not.
For example, here are a couple studies that have looked at this directly:
- – Consuming under 20g of carbohydrates/day compared to a low-fat, high-carbohydrate diet led to 4x increase in HDL concentration (22).
- – A 12-week low carbohydrate diet led to 10% decrease in LDL, a 5% increase in LDL particle size, and a 19% decrease in total VLDL particles (*Smaller LDL particle size is associated with higher risk of developing atherosclerosis compared to larger LDL particles) (23).
- – Six months on a KD led to an 11% decrease in LDL (24).
Keto for Diabetes:
The KD can be an extremely effective therapeutic treatment for diabetes. Since Type 2 Diabetes is hallmarked by insulin resistance, a KD may improve insulin-resistance, associated pathological state via the following: 1) lowering and stabilizing both blood glucose and insulin levels.; 2) Improving insulin sensitivity. and 3) Providing an alternative fuel source through ketone production. For more information, please visit our friends at Virta Health who are actively working with diabetics (https://www.virtahealth.com).
For example, here are a few studies that have seen improvements regarding insulin sensitivity with a ketogenic diet:
- – An unrestricted KD led to incidental caloric-restriction, improved insulin sensitivity, and reduced serum glucose levels, in addition to a reduction in HbA1c (25).
- – KD led to a reduction in body weight, HbA1c, triglycerides, and dependency on diabetic medication (25, 26).
Keto for Epilepsy:
The KD originated in the 1920s as an effective treatment for children suffering from drug-resistant epilepsy. Since then, its highly successful applications have expanded to treat adult epileptic patients as well. Early studies found that 12% and 42% of children, when placed on a KD, experienced full remission or reductions in seizures respectively (27).
In patients whose seizures could not be treated with drugs, KD was able to reduce seizures by more than 50%. Since this, numerous studies have shown this modality to be effective for children and adults with epilepsy.
Keto for Cancer:
Cancer is now being discussed as primarily a metabolic disease in which glucose can fuel its progression. Due to recent light shed on this subject, intensive investigations are underway and have begun to reveal that restricting carbohydrate intake can slow oncogenesis, and a full ketogenic-state may elicit even greater therapeutic benefits. Furthermore, research also suggests that fasting and the state of ketosis may increase the sensitivity of cancer cells to radiation and chemotherapy.
For example, here are a couple studies that have looked at ketogenic therapies in cancer situations:
- – KD can reduce tumor growth and prolong survival in mice (28).
- – KD reduced tumor growth and prolonged survival (29, 30, 31)
- – Stable or partial remission occurred after 28 days on keto (32).
- – KD reduced glucose uptake in cancer cells (33).
- – KD + radiation= greater survival rate and slower tumor growth compared to radiation alone(34, 35).
Keto for Alzheimer’s Disease:
One characteristic of Alzheimer’s disease is insulin resistance in the brain (hence why it’s now being referred to as Type III diabetes), which, in turn, robs this critical tissue of energy. Limiting glucose while introducing ketones may be an effective mechanism for replenishing the energy in the tissue. The higher level of ketone production accompanied with a KD is another example as to why this diet is superior to one that simply restricts carbohydrate intake. Additionally, Alzheimer’s disease is characterized by beta-amyloid deposition, which may also be mitigated by the implementation of a KD.
- – Ketone uptake and utilization is not impaired in those with Alzheimer’s (36, 37).
- – 25% reduction in amyloid- deposition in mice following a KD (38).
- – Ketosis led to improvements on the Alzheimer’s disease Assessment Scale (39).
Keto for Parkinson’s Disease:
Parkinson’s disease develops as a result of neuron death in the midbrain and is typically accompanied by tremors, as well as physical and cognitive impairments. Due to its neuroprotective effects, the KD may help protect neurons, increase energy production and mitochondrial function, lower inflammation, and improve motor function–all of which play a role in Parkinson’s disease.
For example, one study with 5 patients diagnosed with Parkinson’s disease who adopted a KD saw a 43.4% reduction in the Unified Parkinson Disease Rating Scale (40).
Keto and Traumatic Brain Injury (TBI):
Research involving TBI has found that immediately upon trauma to the head, the brain takes up massive amounts of glucose. However, soon thereafter, the brain becomes resistant to taking up and utilizing glucose. This damage, in turn, leads to insulin resistance and inflammation of brain tissue. The anti-oxidative and anti-inflammatory properties of ketones have been shown to not only reduce inflammation but reduce glucose uptake in the brain. The KD may also be a therapeutic treatment option for those individuals who have experienced long-term ramifications of a TBI by providing ketones as an alternative fuel source, that can be readily taken up and utilized by the brain following these traumas.
- – Injured brain can still metabolize ketones (41).
- – Studies in rats on a KD suffering a traumatic brain injury demonstrate improved cognitive performance (42).
In addition to the current therapeutic applications of a KD, below are some of the emerging areas of investigation:
- – Crohn’s disease
- – Multiple sclerosis
- – Autism
- – Rett syndrome
- – Angelman syndrome
- – Depression/anxiety
- – Bipolar disorder
- – Migraines
- – Post-traumatic stress disorder
- – Schizophrenia
- – Huntington’s disease
- – Polycystic ovary syndrome (PCOS)
- – Amyotrophic lateral sclerosis (ALS)
- – Attention deficit hyperactivity disorder (ADHD)
- – Glut-1 deficiency syndrome
- – Glycogen storage disease
- – Inherited metabolic disorders
- – Aging and longevity
1. Do I have to stay keto forever?
-No! Though it’s possible, studies have shown that once you are adapted, you could transition to eating low carb for a few days/weeks before going back to strict keto. However, it is important to understand that this flexibility should come after you are adapted and not just in the beginning.
2. What happens if I fall off the diet?
-If you “slip up” on your KD, it is not the end-of-the-world nor does it mean you should continue to be off the wagon. Unfortunately, having frequent “slip-ups” or “cheat days” may prevent you from becoming “keto-adapted.” However, an occasional “slip-up” for someone who is already “keto-adapted” may not be as detrimental. Get back on track and get back in your routine.
3. Can I have alcohol?
-Certain alcohols, in moderation, may be well-tolerated by some individuals. An example of a ketogenic-friendly red wine is Dry Farm Wines. Also, low carbohydrate beers may permit certain individuals to remain in a ketogenic state. Be sure to avoid sugary liquors and beer as well as sugar-laden mixers.
4. Do I have to count calories?
-Restricting your calories may be important for some individuals, and may aid in the initiation of ketosis; however, not everyone will require calorie tracking to maintain a deficit. It is not uncommon for caloric-restriction to occur inadvertently as a KD tends to be satiating, leaving individuals satisfied with fewer calories.
5. Should I implement a carbohydrate refeed?
-A carbohydrate refeed is not necessary on a KD, as the keto-adapted biological and metabolic changes do not require dietary carbohydrates. There are certain circumstances, however, in which an increase in small carbohydrate influx may be beneficial, however, more research is needed on this topic, specifically with respect to variations of KD, including “cyclic” and “targeted” ketogenic diets.
6. What is fasting?
-By definition, fasting is the absence of caloric consumption for a distinct period of time. There are several different fasting strategies: intermittent, alternate day and even several days.
7.What is fat-fasting?
-Fat-fasting is the consumption of only the macronutrient “fat” during the fasting period. An example is drinking coffee all day, with fats like heavy whipping cream, butter, or coconut oil added in. Some research has shown that since this doesn’t increase insulin, it mimics a fasting state.
8. Will I lose muscle?
-Among the many benefits of being in a ketogenic state is muscle preservation. Research has demonstrated that ketones prevent muscle catabolism. Furthermore, muscle anabolism may actually occur once “keto-adapted.” For these reasons alone, the KD is far more superior to a low carbohydrate diet alone.
9. What are exogenous ketones?
– Exogenous ketones are molecules that, upon consumption, behave similarly to the endogenous ketones that the body produces due to carbohydrate-restriction.
10. Will I be hungry?
-At first, you may experience intense hunger; however, if your diet is well-formulated, once your ketones become elevated and your blood glucose stabilizes, hunger tends to subside.
11. What are Medium Chain Triglycerides (MCT)?
-MCTs are fatty acids that are structurally shorter than long-chain triglycerides, which require processing from the gallbladder. As such, MCTs are rapidly digested and directly used for energy, with a lower propensity for fat storage. These fats are a staple on the KD, in which they can be converted to ketones!
12. Are there fats I should avoid?
-Not all fats are created equal! Omega-6 fatty acids, as well as “trans” fatty acids, should be limited or completely avoided if possible. Rather, one should focus on a diet rich in Omega-3 fatty acids, which have anti-inflammatory properties.
13. Should I track “net,” or total carbs?
-Ketogenic.com suggests tracking total carbohydrates (fiber + non-fiber carbohydrates) in the initial stages of “keto-adaptation;” however, once adapted, one may be able to track “net” carbs (non-fiber carbohydrates – fiber).
14. Can I have coffee?
-Yes! In fact, caffeine may actually increase endogenous ketone production. However, as usual, be careful about consuming caffeine late in the afternoon, as it may affect your sleep.
15. Can I have fruit?
-Some fruits, such as berries, have a low glycemic index and are also lower in carbohydrates. If incorporating berries, try and opt for the fresh, organic, frozen berries
16. Can I have dairy?
-As with other customized properties of the diet, the consumption of dairy is individualized. If digestive or glycemic problems develop due to the lactose and casein in dairy, then dairy may need to be avoided. If you can tolerate it, opt for lower carbohydrate dairy like cheese, heavy whipping cream, and butter, rather than higher carbohydrate products like milk.
17. Do I need to exercise to see results?
-Not necessarily. Positive results can be seen on the KD without exercise; however, exercise will maximize the benefits of the diet. In addition, exercise may help accelerate the adaptation process and allow your body to utilize ketones better.
18. Can I have as much protein as I want?
-Tracking protein is important for anyone who has adopted a KD. Depending on activity level and other metabolic factors, some individuals may be able to tolerate more protein. As mentioned above, at a certain level protein can be glucogenic, so tailor it to your needs. However, we would say to lean toward more, not less, especially for women.
19. What do I do if I hit a plateau with fat loss?
-Hitting a plateau on a KD is possible regardless of one’s goal. Below are actions to consider taking to continue losing fat:
- – Track macros
- – Check calorie consumption
- – Weigh food
- – Alter meal frequency
- – Implement a fasting period
- – Ensure adequate sleep
- – Include exercise
- – Determine food sensitivity by testing blood glucose responses
20. Can I start a KD if I have elevated triglycerides or cholesterol?
-As always, check with your physician first. Despite the high-fat nature of the diet, research has shown that the KD may actually be beneficial for improving one’s blood lipid profile.
21. Can I have too much fat?
– Of course. Calories are still of importance, even on a KD. Simply eating unlimited fat will not guarantee results.
22. How important are strict ketogenic macronutrient ratios?
-Depending on an individual’s current metabolic state, activity levels, and goals, macronutrient profiles will vary among individuals. In general, we recommend that a beginner adopts a macronutrient ratio around 70/25/5 (fat/protein/carbohydrate) and then customize from there.
23. Which sweeteners are best on KD?
– One key to the longevity of a KD is to incorporate foods that are satisfying. If individuals choose to make keto-friendly desserts, learning which sweeteners permit one to remain in a ketogenic state is essential. Ideally, we encourage natural sweeteners like Stevia, Monk Fruit, and Erythritol
-We are excited to see that there are a growing number of physicians who are implementing the KD as a therapeutic treatment option for patients suffering from various diseases/conditions. Due to the difficulty in locating these physicians, be sure to use our “Keto Clinicians” tool to find a ketogenic physician near you!
Time to Transform
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Feed Your Brain!
- 1. Young, C. M., Scanlan, S. S., Im, H. S., & Lutwak, L. (1971). Effect on body composition and other parameters in obese young men of carbohydrate level of reduction diet. The American journal of clinical nutrition, 24(3), 290-296.
- 2. Schachter, S. C., & Sirven, J. I. (2015). Modified Atkins Diet. Retrieved from Epilepsy Foundation: http://www.epilepsy.com/learn/treating-seizures-and-epilepsy/dietary-therapies/modified-atkins-diet
- 3. Sumithran, P., Prendergast, L. A., Delbridge, E., Purcell, K., Shulkes, A., Kriketos, A., et al. (2013). Ketosis and appetite-mediating nutrients and hormones after weight loss. J. Clin. Nutr. 67, 759–764. doi: 10.1038/ejcn.2013.90
- 4. Obici, S., Feng, Z., Arduini, A., Conti, R., & Rossetti, L. (2003). Inhibition of hypothalamic carnitine palmitoyltransferase-1 decreases food intake and glucose production.Nature medicine, 9(6), 756-761.
- 5. McClernon, F. J., Yancy, W. S., Eberstein, J. A., Atkins, R. C., & Westman, E. C. (2007). The Effects of a Low‐Carbohydrate Ketogenic Diet and a Low‐Fat Diet on Mood, Hunger, and Other Self‐Reported Symptoms. Obesity, 15(1), 182-182.
- 6. Sharman, M. J., Kraemer, W. J., Love, D. M., Avery, N. G., Gómez, A. L., Scheett, T. P., & Volek, J. S. (2002). A ketogenic diet favorably affects serum biomarkers for cardiovascular disease in normal-weight men. The Journal of nutrition, 132(7), 1879-1885.
- 7. Volek, J. S., Quann, E. E., & Forsythe, C. E. (2010). Low-carbohydrate diets promote a more favorable body composition than low-fat diets. Strength & Conditioning Journal, 32(1), 42-47.
- 8. Yancy, W. S., Olsen, M. K., Guyton, J. R., Bakst, R. P., & Westman, E. C. (2004). A low-carbohydrate, ketogenic diet versus a low-fat diet to treat obesity and hyperlipidemiaA randomized, controlled trial. Annals of internal medicine, 140(10), 769-777.
- 9. Young, C. M., Scanlan, S. S., Im, H. S., & Lutwak, L. (1971). Effect on body composition and other parameters in obese young men of carbohydrate level of reduction diet. The American journal of clinical nutrition, 24(3), 290-296.
- 10. Volek, J. S., Sharman, M. J., Love, D. M., Avery, N. G., Scheett, T. P., & Kraemer, W. J. (2002). Body composition and hormonal responses to a carbohydrate-restricted diet. Metabolism, 51(7), 864-870.
- 11. Wilson, J. M., Lowery, R. P., Roberts, M. D., Sharp, M. H., Joy, J. M., Shields, K. A., … & D’Agostino, D. (2017). The Effects of Ketogenic Dieting on Body Composition, Strength, Power, and Hormonal Profiles in Resistance Training Males. Journal of strength and conditioning research.
- 12. Volek, J. S., Freidenreich, D. J., Saenz, C., Kunces, L. J., Creighton, B. C., Bartley, J. M., … & Lee, E. C. (2016). Metabolic characteristics of keto-adapted ultra-endurance runners. Metabolism-Clinical and Experimental, 65(3), 100-110.
- 13. Cunnane, S., Nugent, S., Roy, M., Courchesne-Loyer, A., Croteau, E., Tremblay, S., … & Begdouri, H. (2011). Brain fuel metabolism, aging, and Alzheimer’s disease. Nutrition, 27(1), 3-20.
- 14. Hasselbalch, S. G., Knudsen, G. M., Jakobsen, J. O. H. A. N. N. E. S., Hageman, L. P., Holm, S., & Paulson, O. B. (1995). Blood-brain barrier permeability of glucose and ketone bodies during short-term starvation in humans.American Journal of Physiology-Endocrinology and Metabolism, 268(6), E1161-E1166
- 15. Owen, O. E., & Reichard, G. A. (1971). Human forearm metabolism during progressive starvation.The Journal of clinical investigation, 50(7), 1536-1545.
- 16. Phinney, S. D., Bistrian, B. R., Evans, W. J., Gervino, E., & Blackburn, G. L. (1983). The human metabolic response to chronic ketosis without caloric restriction: preservation of submaximal exercise capability with reduced carbohydrate oxidation. Metabolism-Clinical and Experimental, 32(8), 769-776.
- 17. Paoli, A., Grimaldi, K., D’Agostino, D., Cenci, L., Moro, T., Bianco, A., & Palma, A. (2012). Ketogenic diet does not affect strength performance in elite artistic gymnasts.Journal of the International Society of Sports Nutrition, 9(1), 1.
- 18. Martin, C. K., Bellanger, D. E., Rau, K. K., Coulon, S., & Greenway, F. L. (2007). Safety of the Ullorex® oral intragastric balloon for the treatment of obesity.Journal of diabetes science and technology, 1(4), 574-581.
- 19. Cahill Jr, G. F. (2006) Fuel metabolism in starvation. Annu. Rev. Nutr., 26, 1-22.
- 20. Musa-Veloso, K., Likhodii, S.S., Cunnane, S.C. (2002). Breath acetone is a reliable indicator of ketosis in adults consuming ketogenic meals. The American Journal of Clinical Nutrition, 76(1), 65-70.
- 21. Paoli, Antonio, et al. “Effects of n-3 Polyunsaturated Fatty Acids (ω-3) Supplementation on Some Cardiovascular Risk Factors with a Ketogenic Mediterranean Diet.” Marine drugs2 (2015): 996-1009
- 22. Merchant, A. T., Anand, S. S., Kelemen, L. E., Vuksan, V., Jacobs, R., Davis, B., … & SHARE and SHARE-AP Investigators. (2007). Carbohydrate intake and HDL in a multiethnic population. The American journal of clinical nutrition, 85(1), 225-230.
- 23. Wood, R. J., Volek, J. S., Liu, Y., Shachter, N. S., Contois, J. H., & Fernandez, M. L. (2006). Carbohydrate restriction alters lipoprotein metabolism by modifying VLDL, LDL, and HDL subfraction distribution and size in overweight men. The Journal of nutrition, 136(2), 384-389.
- 24. Westman, E. C., Yancy, W. S., Olsen, M. K., Dudley, T., & Guyton, J. R. (2006). Effect of a low-carbohydrate, ketogenic diet program compared to a low-fat diet on fasting lipoprotein subclasses. International journal of cardiology, 110(2), 212-216.
- 25. Boden, G., Sargrad, K., Homko, C., Mozzoli, M., & Stein, T. P. (2005). Effect of a low-carbohydrate diet on appetite, blood glucose levels, and insulin resistance in obese patients with type 2 diabetes. Annals of internal medicine, 142(6), 403-411.
- 26. Yancy, W. S., Olsen, M. K., Guyton, J. R., Bakst, R. P., & Westman, E. C. (2004). A low-carbohydrate, ketogenic diet versus a low-fat diet to treat obesity and hyperlipidemiaA randomized, controlled trial. Annals of internal medicine, 140(10), 769-777.
- 27. Bastible, C. (1931). The ketogenic treatment of epilepsy.Irish Journal of Medical Science (1926-1967), 6(9), 506-520.
- 28. Morscher, R. J., Aminzadeh-Gohari, S., Feichtinger, R. G., Mayr, J. A., Lang, R., Neureiter, D., … & Kofler, B. (2015). Inhibition of neuroblastoma tumor growth by ketogenic diet and/or calorie restriction in a CD1-Nu mouse model. PloS one, 10(6), e0129802
- 29. Stafford, P., Abdelwahab, M. G., Preul, M. C., Rho, J. M., & Scheck, A. C. (2010). The ketogenic diet reverses gene expression patterns and reduces reactive oxygen species levels when used as an adjuvant therapy for glioma. Nutrition & metabolism, 7(1), 1
- 30. Otto, C., Kaemmerer, U., Illert, B., Muehling, B., Pfetzer, N., Wittig, R., … & Coy, J. F. (2008). Growth of human gastric cancer cells in nude mice is delayed by a ketogenic diet supplemented with omega-3 fatty acids and medium-chain triglycerides. BMC cancer, 8(1), 1.
- 31. Freedland, S. J., Mavropoulos, J., Wang, A., Darshan, M., Demark‐Wahnefried, W., Aronson, W. J., … & Pizzo, S. V. (2008). Carbohydrate restriction, prostate cancer growth, and the insulin‐like growth factor axis. The Prostate, 68(1), 11-19.)
- 32. Fine, E. J., Segal-Isaacson, C. J., Feinman, R. D., Herszkopf, S., Romano, M. C., Tomuta, N., … & Sparano, J. A. (2012). Targeting insulin inhibition as a metabolic therapy in advanced cancer: a pilot safety and feasibility dietary trial in 10 patients. Nutrition, 28(10), 1028-1035.
- 33. Nebeling, L. C., Miraldi, F., Shurin, S. B., & Lerner, E. (1995). Effects of a ketogenic diet on tumor metabolism and nutritional status in pediatric oncology patients: two case reports. Journal of the American College of Nutrition, 14(2), 202-208.
- 34. Klement, R. J., & Champ, C. E. (2014). Calories, carbohydrates, and cancer therapy with radiation: exploiting the five R’s through dietary manipulation. Cancer and Metastasis Reviews, 33(1), 217-229
- 35. Abdelwahab, M. G., Fenton, K. E., Preul, M. C., Rho, J. M., Lynch, A., Stafford, P., & Scheck, A. C. (2012). The ketogenic diet is an effective adjuvant to radiation therapy for the treatment of malignant glioma. PloS one, 7(5), e36197.
- 36. Ogawa, M., Fukuyama, H., Ouchi, Y., Yamauchi, H., & Kimura, J. (1996). Altered energy metabolism in Alzheimer’s disease. Journal of the neurological sciences, 139(1), 78-82.
- 37. Lying‐Tunell, U., Lindblad, B. S., Malmlund, H. O., & Persson, B. (1981). Cerebral blood flow and metabolic rate of oxygen, glucose, lactate, pyruvate, ketone bodies and amino acids. Acta neurologica Scandinavica, 63(6), 337-350.
- 38. Van der Auwera, I., Wera, S., Van Leuven, F., & Henderson, S. T. (2005). A ketogenic diet reduces amyloid beta 40 and 42 in a mouse model of Alzheimer’s disease. Nutrition & Metabolism, 2(1), 1.
- 39. Henderson, S. T., Vogel, J. L., Barr, L. J., Garvin, F., Jones, J. J., & Costantini, L. C. (2009). Study of the ketogenic agent AC-1202 in mild to moderate Alzheimer’s disease: a randomized, double-blind, placebo-controlled, multicenter trial. Nutrition & Metabolism, 6(1), 1.
- 40. VanItallie, T. B., Nonas, C., Di Rocco, A., Boyar, K., Hyams, K., & Heymsfield, S. B. (2005). Treatment of Parkinson disease with diet-induced hyperketonemia: a feasibility study. Neurology, 64(4), 728-730.
- 41. Prins, M. L., Lee, S. M., Fujima, L. S., & Hovda, D. A. (2004). Increased cerebral uptake and oxidation of exogenous βHB improves ATP following traumatic brain injury in adult rats. Journal of neurochemistry, 90(3), 666-672.
- 42. Appelberg, K. S., Hovda, D. A., & Prins, M. L. (2009). The effects of a ketogenic diet on behavioral outcome after controlled cortical impact injury in the juvenile and adult rat. Journal of neurotrauma, 26(4), 497-506.