The Ketogenic diet (keto) is an eating plan that features a very low intake of carbohydrates.
Why Is It Called A Ketogenic Diet?
This is called a Ketogenic Diet because this low carbohydrate diet causes your body to release ketones into the bloodstream. It pushes your body into a state called nutritional ketosis.
When you eat carbohydrates your cells utilize it for providing energy. But when you stop eating carbohydrates and get into ketosis, your body has the ability to use your body fat stores to provide ketones for fuel.
Nutritional ketosis is not to be confused with diabetic ketoacidosis, which is a serious life-threatening condition. The two are not the same.
As you can see in the image below, nutritional ketosis is when blood ketones (Beta Hydroxy Butyrate) are in the range of 0.5 and 2 mmol/L. These levels are far from the dangerous condition of diabetic ketoacidosis, where blood ketones may sometimes exceed 20 mmol/L.
(More on ketosis and fuel switch later)
How many carbohydrates are allowed on a Ketogenic Diet (KD)?
There is a lot of confusion about the quantity of carbohydrates allowed per day on a ketogenic diet. Some people consider KD as 20-50 grams of total carbohydrates eaten in a day. However,
In the strictest definition of a Ketogenic Diet, carbohydrate intake should be less than 20 grams a day. (One apple is 20 grams of carbohydrates!)
However, some of you have experienced benefits by simply lowering your daily carbohydrate intake to half or one-third of what you were eating before. This means if you were eating 300-400 grams of carbohydrates daily, you can reduce it to 100-150 grams a day.
It is most important to understand that keto is not a fad diet or a temporary solution to weight loss, it is actually designed to be a lifestyle plan that not only results in successful weight loss but also promotes overall health, energy, and vitality.
Benefits Of The Ketogenic Diet
Better Weight Loss Than on a Low-Calorie Diet
Weight loss on a low carbohydrate diet is more than that on a low-calorie diet. In a study reported in the prestigious journal, New England Journal of Medicine, compared weight loss and lipid levels in two groups of people with an average BMI of 43. Most of the participants had diabetes or metabolic syndrome.
One group was on a low-fat, low-calorie diet and the other on a low carbohydrate diet (LCD). At the end of 6 months, those on the low carbohydrate diet lost more weight than those on the low-fat diet. Ref
Change in Body Composition:
Improved Metabolic Syndrome
Control Of Type 2 Diabetes
Over the last few years, several studies have shown the benefits of using low carbohydrate diets in people with diabetes.
A 2-year study from Virta Health, using continuous remote care and nutritional ketosis based on a well-formulated KD, found that people on the program had more weight loss, got off of diabetes medications, improved fatty liver, lost belly fat when compared to those on usual care. Ref
In fact, the Standards Of Medical Care in Diabetes, 2020, has this to say:
Reducing overall carbohydrate intake for individuals with diabetes has demonstrated the most evidence for improving glycemia and may be applied in a variety of eating patterns that meet individual needs and preferences.
For individuals with type 2 diabetes not meeting glycemic targets or for whom reducing glucose-lowering drugs is a priority, reducing overall carbohydrate intake with a low- or very-low-carbohydrate eating pattern is a viable option.Standards Of Medical Care in Diabetes, 2020
Improves Fatty Liver
Non-Alcoholic Fatty Liver Disease (NAFLD) is a marker of insulin resistance and is a major cause of chronic liver disease, liver cancer and liver transplant worldwide.NAFLD or fatty liver is associated with increased risk of heart disease, diabetes, chronic kidney disease and cancers.
At present, there are no approved drugs to treat NAFLD. Weight loss, exercise, no sugar and fructose, avoiding late-night eating and moving more, all have shown benefits.
People with obesity and diabetes report poor sleep quality. People on a ketogenic diet reported improved sleep, in terms of quality as well as duration. The exact mechanism of sleep improvement is not well understood. However, the improvements may have occurred because of weight loss per se or ketones like BOHB may have effects on sleep. Ref
Treatment of Drug-Resistant Epilepsy
Ketogenic Diets were used in children with uncontrolled epilepsy in the nineteen twenties. KD has been in medical use for about 100 years! Ref With the development of better drugs to control seizures, dietary interventions took a back seat. The older studies had used the classic KD with 80-90% fat.
Improvement in PCOS Symptoms
Polycystic Ovarian Syndrome is one of the commonest hormonal problems experienced by women, particularly young girls. It is basically a problem of insulin resistance, which manifests as excessive body weight, irregular menstrual cycles, infertility, excessive hair growth (hirsutism) etc.
Weight loss improves all the parameters of PCOS. However, the standard of care still recommends a low-calorie diet for weight loss.
This small study was done on 11 women with PCOS. Of the 5 women who completed the low carbohydrate (<20 grams carb /day) 24 weeks trial, most experienced weight loss, lower testosterone, lower fasting insulin. Interestingly, 2 of the 5 women became pregnant despite previous infertility. Ref
Fuel Switch In The Body: The Main Principle Of A Keto Diet.
How Are Ketones Produced? The chief ketones produced in the body are Beta Hydroxy Butyrate (BOHB) and Acetoacetate (AcAc).
As you can see in the image below when your insulin levels are low and glucagon (another hormone) and epinephrine (adrenaline) levels are relatively normal, fatty acids are released from fat cells.
Ketones are made in the liver from the fatty acids released from fat cells. These ketones get into the bloodstream and reach all your cells to provide them with fuel.
The body has three storage depots to use as fuel:
- Carbohydrates from food
- Protein that is converted to glucose in the liver and used for energy
- Stored body fat and ketones
In a regular high carb diet, carbohydrates are the main source of fuel for the body.
1. Carbohydrates, specifically starches and sugars are readily broken down into glucose in the bloodstream, giving the body its principal energy source.
2. At this point, the hormone insulin steps in to remove glucose from the bloodstream as too much sugar can lead to a dangerous condition known as glycosylation.
3. Insulin converts glucose into glycogen. Some glycogen is stored inside the liver as a fuel reserve for the brain, and the rest is stored in the muscles as fuel reserves for the body.
4. When that muscle glycogen is not used through a lack of energy expenditure or exercise, it stays in the muscles.
5. The human body can only store so much glycogen, about 1800 calories worth. When that reserve becomes full both the muscles and the liver send a signal to stop insulin production and excess glucose from dietary carbs begins to build up in the bloodstream, calling for more and more insulin to be released to remove it.
6. Insulin levels surge, and eventually, this leads to insulin resistance.
7. At this point, the liver then sends any excess glucose to be stored as body fat.
8. As high carb intake continues, glucose floods the bloodstream, insulin levels increase, and so do the body’s fat stores.
Eventually, this leads to metabolic syndrome, a set of conditions caused by insulin resistance, which includes obesity, fatty liver, type 2 diabetes, heart disease, and other metabolic issues.
While this carb cycle may not occur in everyone, for many who are obese, have a sensitivity to carbs, or who do not expend the required amount of stored energy, this is often the case and the main culprit behind obesity.
High Carb Intake = High Glucose In The Blood = High Insulin = Body Fat Stores
Lipolysis And Ketosis
Under normal dietary conditions, ketones play no role in fueling the body and energy production, but during a Ketogenic Diet, ketones become the central player, fueling the body and at the same time flipping on the fat-burning switch.
When you eat fewer carbohydrates, your body goes into a state called lipolysis, (the breakdown of fat), a most efficient biochemical pathway to weight loss and a scientifically proven alternative to using glucose for energy.
Botton Line:On a Ketogenic Diet, your body starts utilizing your fat stores for fuel, instead of carbohydrates from your food.
Types Of Ketogenic Diets
- Classic Ketogenic Diet
- Well-formulated Ketogenic Diet
- Atkins Diet
- Cyclical Ketogenic Diet
- Targeted Ketogenic Diet
1) Classic Ketogenic Diet
This is the very low carbohydrate and protein and high-fat diet which was used in the treatment of uncontrolled epilepsy in the nineteen twenties. The percentage of fat is 80-90% with proportionately low carbohydrates and low protein.
2) Well-Formulated Ketogenic Diet
This term comes from Dr. Stephen Phinney and Dr. Jeff Volek, who are two of the world’s foremost researchers in low carbohydrate diets in medicine. In their program, the food included is chiefly whole foods, designed to maintain ketosis and retain lean body mass. The amount of carbohydrates is personalized. Usually, it is an average of about 70 grams a day. The recommended daily protein intake is from 1.2 to 2.0 g/kg per day of the reference weight.
3) Atkin’s Diet
The Atkin’s Diet is a low carbohydrate diet promoted by Cardiologist Dr. Robert Atkins. His first book, Dr. Atkins’ Diet Revolution was published in 1972.
The Atkin’s Diet is divided into 4 phases. It starts with an induction phase of 2 weeks when daily carbohydrate intake is restricted to 20 grams. This is followed by subsequent phases, during which you may gradually increase your carbohydrate intake. The duration depends on how much weight you have lost. The last phase is the maintenance phase.
4) Cyclical Ketogenic Diet
This plan is sometimes used by athletes, bodybuilders, weight-lifters and anyone participating in high-intensity exercise. It includes 5 days of KD followed by 2 days of high carbohydrate intake. This is designed to use the carb-loading days to replenish the glycogen lost by muscles during intense exercise.
5) Targeted Ketogenic Diet
This is similar to a standard ketogenic diet, except that carbohydrates are eaten around workout times. This is based on the concept that carbohydrates will be processed faster through exercise. Muscles need more energy when working out.
Other Ways Of Achieving Ketosis
In addition to a Ketogenic Diet, what other ways are there to achieve nutritional ketosis?
- Intermittent Fasting
- Exogenous Ketones
Physical exercise can cause ketosis, called Post-exercise Ketosis. This was initially reported way back in 1909, by Forssner who noted that his urine ketone levels increased after a brisk walk of 4 km in 36 minutes. Ref
In the image below, you can see that blood ketone levels had gone up after cycling for 90 minutes. This graph is in a group of untrained people. The responses may be different in well-trained athletes.
In this image below (from the same study) you can see how exercise and a low carbohydrate diet kept one of the participants at a higher level of ketosis, versus normal or a high-carbohydrate diet. Therefore diet is primary but exercise will definitely add to the benefits. (Exercise has numerous benefits besides weight loss).
3) Exogenous Ketones
Exogenous ketones are supplements containing primarily beta-hydroxybutyrate and acetoacetate (along with a bunch of other stuff). When you drink these supplements you are supposed to get into ketosis.
Endogenous versus exogenous ketosis:
Endogenous, meaning inside, is the ketosis that you achieve through a ketogenic diet or prolonged fasting. Exogenous, as the term implies, is ketosis from the outside, achieved by taking ketone supplements.
One of the biggest differences between endogenous and exogenous ketosis is the time frame. Endogenous ketosis can take a few days or longer depending on your metabolism, but exogenous ketosis can start within about 30 minutes of taking ketone supplements, but the ketosis is not sustained.
As this study Ref shows, whose chief author is Dr. Brianna Stubbs, who is one of the world authorities on exogenous ketones, the ketosis achieved through supplements lasts for about 4 hours. This is in contrast to nutritional ketosis achieved through a ketogenic diet or prolonged fasting, which can last a long time.
Additionally, the question of whether exogenous ketones help in weight loss is open to debate. A study was done on healthy males, where they were given an intravenous infusion of D-Hydroxybutyrate. Multiple parameters were measured. They found that although blood glucose levels had reduced, lipolysis (fat breakdown) had reduced as well. Ref
Then comes the question of cost, availability, taste, whether ketone esters or ketone salts, additives in the supplements etc. Exogenous ketones may have a role in managing cognitive decline and in athletic performance. (More on this in later posts)
Botton Line: We do not recommend exogenous ketones on the MDS Program because we like to stick to proven methods like foundational lifestyle changes first.
However, if you find that adding exogenous ketone supplements help you, please go ahead!
Should You Test For Ketones?
You can find many ketone testing kits in the market known as Ketosticks or Ketostix to test your urine for ketones. Your doctor can also order labs to test for ketones. (On the MDS Program we do not use testing for ketones but some of you have seen good results with testing).
This can be a good way to ascertain if your body has reached a state of ketosis and can be psychologically comforting. However, it is important to note that ketosis can be present without showing ketones in the urine.
Typically, a carb intake of up to 100 grams will induce ketosis, but ketones are rarely present in urine at this level of carbs in the diet. Generally, ketones will show up in urine when intake is at 30 grams of carbs per day or less, though this too can vary.
One of the more important functions of ketone testing may be to allow the monitoring of the effects of carbs on ketosis as you progress. As you lose weight and progress towards your goal, you may begin to introduce more carbs to see the effect it has on your weight loss so you can find the right balance, and these test kits can be really helpful to that end.
Working Out and Ketosis:
Additionally, if you workout and as a result can tolerate more carbs and still lose weight, this testing may also help evaluate those efforts. As long as trace ketosis is maintained, carbs can be gradually added to the diet.
It is best not to obsess about the results if you show lower than expected readings. Do remember that just as finding dark readings can give you mental comfort, their absence can be distressing.
As long as you are losing weight, maintaining energy and feeling good, that is all that matters.
Acetone breath or “keto breath” can indicate the presence of ketones, which turn to acetone in the body. The taste is typically metallic and easily fixed with sugar-free gum.
Ketone Induced Changes In Urine: Ketosis can affect urine, creating a sort of distilled sour scent.
Rules Of The Ketogenic Diet
CARB INTAKE: Ideally less than 20 grams of carbs per day.
Most of the carbs should come from non-starchy vegetables. Green, fibrous vegetables are your best choices, though many other low-carb vegetables are fine.
Always eat a carb-containing food with a protein or a fat, for example, have a piece of cheese with cucumbers or salad with chicken.
HEALTHY FAT INTAKE: Don’t be afraid of fats. Fat is 90% ketogenic. Remember that in ketosis, fat is the main energy source for the body, helps remove hunger, provides key macronutrient requirements and natural fats are fine when controlling carb intake. They also have many other benefits, including providing the building blocks for several important hormones and bodily structures.
BEST FATS: The best fats are monounsaturated and saturated, including olive oil, grass-fed butter, red meat, and coconut oil. Margarine is never advised, as it is fake and interferes with ketosis. Natural whole fats are always the best.
Avoid processed and man-made polyunsaturated fats, including soybean oil, corn oil and cottonseed oil.
ADEQUATE BUT MODERATE PROTEIN: Protein is both 46% ketogenic and 58% anti-ketogenic, as some protein will convert to glucose in the bloodstream and inhibit ketosis, so intake should be enough to prevent muscle loss, but not so much that will disrupt ketosis.
EAT TO SATISFACTION: Eat when you are hungry. Eat until you feel satisfied.
INCREASE SALT INTAKE: A little extra salt, can help avoid possible side effects known as keto flu as your body adjusts to ketosis, including headaches, muscle cramps or weakness that occur as result of an electrolyte imbalance and since a low carb diet is naturally diuretic, (makes you pee more) you don’t have to avoid salt to minimize water retention.
Get that salt from 1 to 2 cups of broth daily or use salt to season your food.
Caution: Please ask your doctor about increasing salt, and if you are being treated for a condition that requires limited sodium intake.
DRINK LOTS OF WATER: Some of you will feel an increased thirst on a Ketogenic Diet. Drink enough water to keep yourself adequately hydrated. The more active you are the more hydration you will need.
Frequently Asked Questions
Q) How can it be healthy to cut out carbs from my diet?
A) The ketogenic diet does allow you to eat non-starchy vegetables, which are the healthiest carbs. It is the unhealthy carbs that are cut out, like refined sugar and sweets that do nothing but harm the body along with grains, like rice and pasta, and whole grains, which are counterproductive to weight loss and ketosis.
There are no essential carbohydrates, though there are essential fatty acids (like omega 3) and essential amino acids (building blocks of proteins). In this context essential means, your body doesn’t have the ability to make them.
Another important factor is that while you eliminate carbs, you also increase the intake of healthy fats and certain fats are very good for you, including avocado, meats, butter, cheese, coconut, and olive oil.
Q: Won’t the high fat intake cause high cholesterol?
Q: Aren’t whole grains good for me?
A) Whole grains are grains that contain 100% of the original kernel. All of the bran, germ, and endosperm – must be present to qualify as a whole grain.
It is important to find out what applies to you. Often the benefits may come from the food that you have exchanged for the whole grains. What do I mean?
For example, if you were eating bread and biscuits before but have switched to eating whole grains now, your blood glucose will likely be lower than before. Here the impact is because of what you have given up rather than what you have added.
Q: Are there any side effects of cutting out carbs?
A) Some people experience digestion and diarrhea problems, but this common side effect typically goes away after about four weeks. Eating more high-fibre vegetables, like leafy greens and broccoli helps and magnesium supplements can alleviate constipation.
Q: I only need to lose 20 pounds (about 10 kgs). Is it a keto diet right for me?
Definitely, a keto diet can help you lose 20 pounds or 150 pounds. If you are insulin resistant, a low carbohydrate diet is a better option for you.
Q) Should I look at net carbs?
The net carbohydrate formula is Total Carbohydrate Count minus the Fiber Count = Net Carbs.
The more fibre a food has, the less impact its carbohydrates will have on blood sugars. Fibre does not negate carbs, it just lowers the impact of carbs that naturally occur within that food.
For example, an avocado has 17 grams of carbs, and 13 grams of fibre, yielding 4 grams of net carbs. 1 cup of ice cream has 32 grams of carbs, but mashing in an avocado to that ice cream will not reduce it by the 13 grams of fibre in the avocado.
Sugar count listed in the carbohydrates section of a food label is exactly that, sugar. On the MDS Program, we do not encourage you to focus on net carbs. It is much easier to check total carbohydrates in food.
Q: How long will it take to reach ketosis?
A) This varies from person to person. In some people, it may take 2-4 days of being on <20 grams of carbohydrates a day, while others may take longer.
The time taken depends on several factors like your previous carbohydrate intake, protein intake, your physical activity, nighttime eating etc
Q: Is frequent urination normal?
A) Yes! Ketones naturally increase urination (diuretic effect). Another important factor to bear in mind is sodium loss. That is why we recommend increasing salt intake when on a ketogenic diet.
Q: Will I ever be able to eat pasta, bread or sugar again?
A) When following the Ketogenic diet, it is very important to be strict in the elimination of carbs initially, to allow the body to fully enter into ketosis. As you begin to lose weight, you can slowly integrate some carbs into your diet, typically in the form of more vegetables, nuts, and possibly berries.
However, you need to monitor your weight loss to see how these carbs affect it, in order to find the right balance.
Once you reach your weight loss goals, you can indulge on occasion, but then return to the diet immediately. As with any healthy eating strategy, being mindful of the impact and toxic load of certain foods and ingredients is key.
Keep in mind, keto is a lifestyle, not a temporary diet, so you must be vigilant about your choices, basically forever, and returning to high-carb eating will only lead to weight gain.
The common-sense view is that whenever you return to a lifestyle that made you overweight, to begin with, it can only do so again and again.
Q: How can I deal with missing sweets and carbs?
A) There is an adjustment period, and there may be struggles, but the truth is once you kick the sugar habit, your body and mind will adjust, and you will be better for it.
- If you are insulin resistant a ketogenic diet will work for you.
- However, many people find it difficult to stay on a ketogenic diet long-term.
- If you are eating an Indian Vegetarian diet, which is predominantly grain and legumes based, you may find it difficult to eat a ketogenic diet.
- Because of these reasons, we recommend a lower carbohydrate intake than before (may not be as low as a ketogenic diet) along with Time-Restricted Eating-Intermittent Fasting on our program.
Here is a good resource for everything low-carb. Diet Doctor
(Dr. Kar is listed on the DietDoctor website as a Low-Carb Clinician)
Video Can You Eat An Indian Vegetarian Ketogenic Diet?