Any diet, by definition, is a group of foods consumed for a certain period of time. A “diet” can be as simple as an average daily meal or it can also be part of a treatment program for specific medical conditions. The ketogenic diet, which allows someone to enter a state of nutritional “ketosis”, has long been used in the treatment of epilepsy in children – but its benefits go way beyond this.
As you’ll learn, recent studies show that a ketogenic diet can have many uses and benefits – including weight loss, reduced inflammation, cancer-prevention, as more.
History of Ketogenic Diets
The ketogenic diet was first introduced in 1924 at the Mayo clinic by Dr. Russel Wilder who started the diet to treat epileptic patients. He put his patients on a “fast” and found that epileptic symptoms became less frequent. The popularity of this diet as a means of controlling epilepsy has decreased since this time since powerful anticonvulsant drugs have been invented, but this doesn’t mean that ketogenic diets are not promoted for better health any longer.
Since its introduction in the 1920s, the ketogenic diet and entering ketosis remains controversial until today. Although it has many benefits and is a natural approach to controlling disease in some cases, many doctors and patients often find it easier to administer pills than to adhere to a ketogenic diet that they find “strict’ and restrictive. The exact mechanism by which the ketogenic diet works still isn’t 100% known, but the results of ketosis that have been researched for years are staggering.
What is A Ketogenic Diet?
Today ketogenic diets get the most attention when it comes to weight loss and blood sugar control. “Burn fat by eating more fat” is one simple way to describe the approach that allows someone to enter and maintain in ketosis.
The classic ketogenic diet incorporates a very high fat ratio compared to carbohydrates, with a moderate to small amount of protein. In fact carbohydrates are kept extremely low, while fats are eaten in much larger quantities than most people are used to. As high-carbohydrate food sources are eliminated from the diet, natural fat sources take their place. The ratio of food is aimed at inducing and maintaining a ketosis state. Why more fat and moderate proteins in ketogenic diet? Fats do not affect the hormone called insulin since they have no effect on raising blood sugar levels (more about this to come). (1)
During ketosis, fat becomes the “fuel” that the body runs off instead of glucose (or sugar molecules) which are found in carbs and normally burned for energy during a standard diet. At the same time, protein levels are kept within a moderate range which supports weight loss and metabolic function. Daily meals provide protein in amounts just enough to allow for healthy growth and repair. Someone’s calories are usually kept in sufficient amounts which supports the maintenance of a healthy weight and prevents a dip in metabolic function due to the body thinking it’s “starving”.
So in other words, just remember that this is how the ketogenic diet and ketosis is summarized: a diet of adequate protein intake, very high fat intake and very low carbohydrate consumption which allows for fat to be burned for energy instead of carbs.
How Does Ketosis Work?
Calories during ketosis are balanced based on fat consumption. So the higher the fat intake, the lower carbs and protein will need to be.
Calorie breakdown during ketosis typically follows these proportions:
o 70-75% of daily calories come from fat
o 20-25% come from protein sources
o 5-10% come from carbohydrates in food
This ratio of food is best at inducing and maintaining a ketosis state because fats do not affect insulin and blood sugar levels. Carbohydrates do dramatically effect and control blood sugar, which is the primary reason that nearly all carbohydrates are kept low.
Why do carbs control blood sugar? They are the first source of “energy” that the body uses. This is because carbohydrates are the easiest to digest and absorb. In a regular average meal, carbohydrates make up most of the calories. The body is inclined to use up the carbohydrates as energy and to store the other nutrients from food (fats and proteins) to be used later. Extra carbs and proteins are stored as fat. In a ketogenic diet, most of the calories are from the fats rather than carbohydrates and although carbohydrates at very low levels are still present (from vegetables), they are immediately used up by the body for quick energy.
When the body runs out of carbohydrates, it shifts to using fats and proteins for energy instead. In essence, the body uses energy in a sort of hierarchal way. First, the body uses carbohydrates from foods while they’re available. The body moves on to fats as a next alternative source when not enough glucose (another name for sugar) is present. (2)
Proteins can affect insulin and blood sugar if consumed in large quantities, which is why they are also kept to moderate or small amounts (about 56% of excess protein eaten is converted to sugar which can stall ketosis by stopping fat burning). The body will react to the glucose released from protein breakdown if protein levels are kept high (which is usually the case during a typical low-carb diet like Atkin’s for example).
Protein conversion into energy is the last stage, which usually occurs in extreme deprivation of carbohydrates and only when fat stores are already used up. Protein digestion leads to muscle wasting, as the body digests the proteins in the muscles in order to keep enough energy going to survive.
What Are Ketones?
As you’ve learned, a ketogenic diet is specially designed to induce ketosis in the body. The central nervous system cannot use fat as an energy source, so it normally utilizes glucose. But after 3–4 days without carbohydrate consumption, the nervous system is ‘forced’ to find alternative energy sources.
High-fat/low-carbohydrate diets lead to the production of higher-than-normal levels of so-called ketone bodies (KBs) that are produced within the liver. So in the other words, ketones are the result of ketosis when glucose in the body drops to very low levels and the body switches to fat as a source of energy. The body burns the stored fat it has and converts it into energy (which results in rapid weight loss). The fat metabolism produces molecules called ketones.
Ketones are compounds composed of 2 groups of atoms linked together by a carbonyl functional group. They can be used by the body’s cells within the mitochondria as a source of energy, especially brain cells. The brain in particular, which is largely made up of fat and requires a lot of energy for ongoing maintenance and function, can use ketones for about 70 to 75% of its energy requirements.
The more the body burns fat for energy instead of glucose, the more “ketone bodies” the body produces. At the same time that ketone bodies increase in the blood, blood sugar levels drop; these two have an inverse relationship with one another. As blood sugar drops and simultaneously ketone body levels rise, the body experiences what is called “ketosis”, or “nutritional ketosis”. During ketosis, most people will experience rapid weight loss as all of their fat stores become depleted.
What’s It Like Entering Ketosis?
Ketosis can be induced either purposefully or somewhat accidentally due to some health conditions. How long does ketosis take? The desired effects of ketosis usually take longer to be achieved but subtle effects are seen between 6 and 8 weeks. Most people are able to adjust by the end of the first week after starting on a ketogenic diet. Others may take up to 2 weeks. It may take up to 12 weeks for the body to adapt 100% to fat burning.
Ketosis can be induced in the following conditions:
Unintentionally, starvation is one way in which people have entered ketosis. Starvation and fasting states results in inadequate or no intake of food that the body can digest and convert into glucose. The body normally enters starvation mode during sleep, skipping meals or when fasting. The lack of food intake results in a drop in blood glucose levels. Glycogen (stored glucose) stores are mobilized. They are converted into glucose for the body to use as energy ketones as sources of energy.
Another way to purposefully enter ketosis is by carefully managing your diet. More directions for entering ketosis are found below, but keep in mind that this can take up to several months and during the transition phase, side effects can occur, mostly due to the very low levels of carbohydrates someone is consuming.
Some side effects of entering ketosis include:
• Cravings for carbohydrates
• Mild irritability
• Mood changes
• Loss of appetite
• Trouble sleeping
• High cholesterol (if too much unhealthy fats)
Ketogenic Diet Benefits
The body becomes more of a fat-burner than a carbohydrate-dependent machine as ketosis goes on. Research shows that a diet high in carbohydrates is linked to the development of several disorders such as insulin resistance and diabetes, since fluctuating blood sugar levels can lead to inflammation and many problems, so ketosis can provide benefits to many people.
Since high levels of processed carbohydrates and sugary foods have been linked to insulin imbalance and an increased risk for developing diseases like diabetes, heart disease, and cancer, a ketogenic diet can greatly help someone to improve their condition. One of the things that ketogenic dieters love is that there is no calorie-counting, measuring food portions, or strange meal replacements required. They also like the feeling of never “going hungry”, since low-carb/moderate-protein/high-fat foods tend to be very filling.
The biggest benefits of ketosis come from the ability to control weight gain (or to lose weight, even rapidly) and to control insulin. For many physicians, obesity is one of the most challenging problems confronted in daily practice and often it’s accompanied by diabetes. Despite the efforts of both patients and physicians, both disorders are increasing in prevalence throughout many parts of the world.
As researchers describes the benefits of ketosis for weight loss: ”For many years, nutritional intervention studies have been focused on reducing dietary fat with little positive results over the long-term. One of the most studied strategies in the recent years for weight loss is the ketogenic diet. Many studies have shown that this kind of nutritional approach has a solid physiological and biochemical basis and is able to induce effective weight loss along with improvement in several cardiovascular risk parameters.” (3)
Someone is a lot more likely to over consume calories when they eat low protein, low fat, high-carb foods that leave them feeling hungry. Foods that spike insulin levels- like sugary treats and processed grains- tend to make us hungry and not satisfied for very long, so we look for more food quickly after eating them. This creates a cycle of eating high-carb foods and then consequently wanting even more high-carb foods. This ultimately leads to consuming too many calories and therefore usually to weight gain.
Ketosis also does a great job of controlling insulin. Insulin is the primary hormone that the pancreas release to control glucose (sugar) in the blood. Every time we eat carb or sugar-containing foods, insulin is released.
Carbohydrate are easily absorbed and stored and digestion starts in the mouth. As soon as the food is chewed, amylase (enzymes that digest carbohydrates) in the saliva are already acting on the carbohydrates. In the stomach, carbohydrates are further broken down and are immediately absorbed once it enters the small intestines. In the blood, carbohydrates immediately increase the blood sugar levels.
This stimulates the immediate release of insulin. High blood sugar levels trigger a release of high levels of insulin, and this cycle continues on every time we eat more sugar or carbs. This hormone causes the sugars to be stored immediately in the body tissues to lower the blood levels. The tissues can develop resistance to insulin when it is constantly exposed to it at high levels. The body tries to solve this problem by becoming resistant or unresponsive to insulin, or “insulin-resistant”, which is another name for type 2 diabetes. Obesity occurs at the same time, as the body tends to rapidly store the carbohydrates as fat. Diabetes and cardiovascular disease can result from this cycle.
Foods that are considered low-carb almost all have low scores on the “glycemic index”, which is another way of saying that the foods are absorbed into the blood stream more slowly and won’t result in a sudden surge of sugar in the blood- which can lead to health problems and weight gain. Foods that are not considered low-carb are those that have high levels of sugar, starch, and are lacking protein and healthy fats.
A ketogenic diet high in fat and low in carbohydrates has been found to play a role in reducing and improving certain medical conditions including:
• Alzheimer’s disease
Research shows that memory function improves when a patient with Alzheimer’s disease follows a ketogenic diet. They regain a few of their thought and memory functions.
• Other neurological disorders
Parkinson’s disease and ALS (amyotropic lateral sclerosis) are some of the neurological disorders that benefits from ketogenic diet. The diet provides mitochondrial support in affected nerves. As such, the symptoms improve. Some studies have even found that ketosis can improve general thought-processing and cognitive function. One study found that diet-induced ketosis improved behavioral performance in rats when their cognitive function was measured using a maze test. Results showed that a ketogenic diet significantly increased blood ketone levels in both young and old rats which improved their ability to problem solve. (4)
Carbohydrates are the main culprit in diabetes. By cutting back on the consumption in ketogenic diet, there is better blood sugar control. Other diabetes treatment plans work better in conjunction with this diet.
• Gluten allergy
A lot of people are undiagnosed with gluten allergy. Following a ketogenic diet showed improvement in related symptoms like bloating and digestive discomforts. Gluten is high in most carbohydrate-rich foods. By eliminating a large variety of carbohydrates foods in the diet, gluten intake is also kept at a very minimum. Hence, gluten symptoms are also eliminated.
• Weight loss
Ketogenic diet has found a niche in mainstream dieting trend. It is now part of many dieting regimen, due to its observed side effect of promoting weight loss. At first, the idea of losing weight with a high fat diet raised many eyebrows.
Finally, one of the fields getting the most attention when it comes to ketogenic diet benefits is brain health. There is evidence from some clinical trials and animal studies that a ketogenic diet can provide symptomatic and disease-modifying activity in a broad range of neurodegenerative disorders. These include Alzheimer’s disease and Parkinson’s disease, as well as traumatic brain injuries and strokes. (5) How exactly ketosis affects the brain isn’t totally understood, but plausible explanations revolve around “neuroprotection from enhanced neuronal energy reserves”. This basically means that ketosis can improve the ability of neurons to resist metabolic challenges, and also might have antioxidant and anti-inflammatory effects.
How Does Ketosis Compare to the Paleo Diet?
Both ketogenic diets and the paleo diet have similar goals of controlling blood sugar and weight, promoting better health, getting rid of processed foods altogether and focusing on natural nutrient-dense foods that are filling. However they do have some substantial differences and following the paleo diet won’t result in ketosis without some changes.
Ketogenic diets promote eating high amounts of fats even more so than high amounts of protein; this is how a ketogenic diet differs from the paleo diet, or any standard low-carb diet like The Atkins Diet for example. For most people, switching to a ketogenic diet means they are eating much less carbs, less protein and much more fat than they normally would on the paleo diet.
A typical ketogenic meal would include a moderately small amount of protein (not an unlimited amount) from a source like beef, eggs, or chicken, plus a generous serving of natural fat (for example oil, butter, or natural saturated fat from meat), plus some non-starchy vegetables (meaning no potatoes or squash, but vegetables like leafy greens, broccoli, peppers, or tomatoes instead).
In contrast, the paleo diet doesn’t limit the amount of protein someone can eat to small quantities and also usually allows for unlimited, or at least large amounts, of vegetables. Paleo diets also allow for fruit while most ketogenic diets do not. Although all ketogenic diets limit carbohydrate foods severely, the exact amount of carbs encouraged on a ketogenic diet really depends on the specific kind that is being followed and how quickly someone wants to see results. All in all, since it’s ideal to get about 85% of calories from fat when on a ketogenic diet, plus some of the remainder from protein, so there is not much more room for consuming carbs.
There are a range of ketogenic, paleo and low-carb diets that are promoted today, all of which vary in terms of foods allowed, severity and duration. Generally speaking all ketogenic diets however (and all very low-carb diets in general) will have these characteristics in common when compared to the paleo diet:
• Higher fat intake
• Smaller protein intake (higher on the paleo diet or a standard low-carb diet)
• Very low carbohydrate intake and lower glycemic index score
• Very low sugar, low starch (no fruit allowed and vegetables limited to small quantities)
• Usually a high intake of, vitamins, minerals, antioxidants, and plant phytochemicals through fresh non-starchy vegetables on the paleo diet
How to Enter Ketosis
If you’re already following the paleo diet or a low carb diet, the transition into ketosis shouldn’t be so extreme. But if you eat a standard American diet, it will require more time and adjustment. Follow the proportions described above when it comes to how much fats, versus proteins, versus carbohydrates that you’re eating (remember about 75% of your calories come from fat sources). Most people entering ketosis will require about 70-75% of calories coming from fat, 20-25% coming from protein foods, and 5-10% from carbohydrate foods.
You will want to continue consuming around 20-25 grams of carbohydrates each day, even when on a low carb diet, because this amount is required for the body to function properly. This is still considered very “low carb” and ketogenic, but ensures you are maintaining your health at the same time as losing weight.
In order to allow your body to enter ketosis and for you to see the most benefits, It’s best to limit or keep your eye on your overall calorie intake as well as your carb intake (especially if you want to see fast weight loss results). It’s also extremely beneficial to eat real, unprocessed foods and not packaged foods claiming to be “low-carb”. The amount of calories that you need really depends on your unique composition and lifestyle. If you are someone who exercises often, you can afford to add more calories to your meal plan each day because you use up more energy, so aim to include 200-300 more calories to avoid becoming overly hungry.
You will likely experience a very rapid decline in appetite while on the ketogenic diet. As some studies have found, “in the short term, high-protein, low-carbohydrate ketogenic diets reduce hunger and lower food intake significantly more than do high-protein, medium-carbohydrate non-ketogenic diets.” (6)
To understand which foods you should include in a ketogenic diet and which to avoid, refer to the list below:
Foods to Include on Ketogenic Diet:
• Meats: Any type. This can include beef, pork, game meat, chicken, etc. It’s best to choose organic or grass fed meat.
• Fish and Shellfish: Any type. This can include salmon, mackerel, shrimp, lobster, scallops, etc.
• Eggs: They can be cooked anyway. It’s best to choose organic eggs.
• Fats: This can include oils like coconut oil, olive oil, palm oil, or butter, nuts, seeds, and avocado.
• Non-Starchy Vegetables: All kinds. This can include any leafy greens, all cabbage, cauliflower, broccoli, Brussels sprouts, asparagus, zucchini, eggplant, spinach, mushrooms, cucumber, lettuce, avocado, onions, peppers, tomatoes etc.
• Dairy Foods: Always select full-fat options like real butter, cream (40% fat), sour cream, Greek/Turkish yogurt and high-fat cheeses. Avoid low fat or flavored kinds.
• Nuts: all kinds. This can include almonds, cashews, peanuts, etc.
• Drinks: only water, seltzer, unsweetened coffee, unsweetened tea.
• * some ketogenic diets allow for berries: These are the only fruit allowed and are okay in very small amounts if following some protocols
Foods to Avoid on Ketogenic Diet:
• Foods with High Sugar Levels: soda, candy, juice, cookies, cake, sports drinks, ice cream, etc. Also avoid using added cane sugar or anything very sweet like honey and maple syrup.
• Carbohydrate Foods: Breads, pastas, rice, potatoes, any grains. This even includes products that say they are “whole grain”.
• Starchy Vegetables: All vegetable “tubers”- a family of vegetables that grow under the ground- including potatoes, carrots, radishes, and beets, turnips, and parsnips.
• Alcohol: All kinds should ideally be avoided, or only had in very small amounts
• Fruit: All fruit is off limits except sometimes for berries on occasion in small amounts
• Drinks: Anything with sugar added like soda, juice, or sweetened coffee and tea
Is Ketosis Dangerous?
Each person reacts differently to a ketogenic diet; some take to it very easily and find that they feel better almost immediately, while others struggle a bit more. Normally the more dependent someone is on carbohydrate foods prior to starting the diet, the more difficult it will be for them to give these foods up. However, most negative feelings resulting from a ketogenic diet usually go away with some time.
It’s also important to realize that many of the potential cons of eating very low carb diets are actually psychological affects and not physiological ones that can harm your safety, meaning you may need to deal with having food cravings or feelings of deprivation. These feelings usually will go away with time, as the person becomes more comfortable eating in a low-carb, ketogenic way. Ongoing motivation is usually discovered because ketogenic diets quickly produce fast results, making the person want to stay on track.
The body actually normally enters a ketosis phase. This happens during the fasting state. An example of which is during sleep. The body tends to burn fats for energy as the body repairs and grows during sleep.
Can you exercise during ketosis? According to studies, yes you safely can. (7) Studies have found that aerobic endurance exercise by well-trained athletes is not compromised by four weeks of ketosis. The athletes’ bodies accomplish a dramatic physiologic adaptation that conserves limited carbohydrate stores (both glucose and muscle glycogen) and makes fat the predominant source of energy.
Although ketosis is usually safe, there are some side effects. In some cases a severe lack of insulin allows the ketone levels to increase to the point that they can be toxic to the body. This condition is called ketoacidosis. However, ketosis induced by diet is not enough to cause this condition. This effect can only occur when the body’s control mechanism fails.
The following are some of the reported side effects of the ketogenic diet and trying to enter ketosis: (8)
• Kidney or gall stones
• Slowed or poor growth
• Exacerbation of gastro-oesophageal reflux”
• Increased bruising
• Increased risk of fractures
• Excess ketosis and acidosis
• Psychosocial food refusal
Women with epilepsy using the ketogenic diet can experience:
• Menstrual irregularities
• Eye problems
• Decreased bone density
• Needing to avoid many common foods at restaurants, parties, etc. can be overwhelming and cause stress since it can be hard to stick with low carb offerings
• Possible feelings of deprivation since many carbs like bread and pasta tend to be some of people’s favorites
• Potentially spending more money on groceries since protein foods can be expensive at times
Micronutrient deficiencies can also result from the restrictions as well. Most carbohydrate-rich foods are also rich in vitamins and minerals. The severe restrictions on carbohydrate intake may cause deficiencies of these essential nutrients. It is very important to also consider the micronutrient (vitamins and minerals) intake along with the macronutrient (fats, proteins and carbohydrates) counting and proportioning in meals. Supplementation may also be necessary to avoid deficiency states.”
The Bottom Line on Ketosis and Ketogenic Diets
Ketosis has some definite benefits, especially when it comes to weight loss and appetite control. At the same time, it’s not easy for everyone to adhere to considering the strict restrictions is places on some “favorite foods”, like carbs, starchy veggies, fruit and sweet snacks.
If you’re looking to give ketosis a try in order to increase your fat-burning abilities and general health, you’re not alone – this type of diet is growing in popularity as more people switch to paleo diets (or other grain-free, no-sugar, low-carb diets) and then decide to take the ketosis-plunge. Although it might have a bad reputation and seem a bit extreme, ketosis can have therapeutic abilities’ for the right people. Just take your time getting used to the lifestyle change and inducing ketosis if you plan to try it out, this way you keep side effects to a minimum and don’t love motivation too quickly.