by Sue Kira, Naturopath & Clinical Nutritionist
The ketogenic diet, often known as the keto-diet, is a very low-carb, high-fat, moderate protein style diet that involves drastically reducing carbohydrate intake and replacing it with fat.
The reduction in carbs puts your body into a metabolic state called ketosis which shifts the body’s metabolism away from using carbs for energy, to fat and ketones. When this happens, your body becomes incredibly efficient at burning fat to get the energy it needs.
When fat turns into ketones in the liver it supplies the brain with energy. The effect of a keto diet creates massive reductions in blood sugar and insulin levels, but along with this, the increased ketones have numerous other health benefits.
Ketogenic diets are thought to be beneficial for those with diabetes, cancer, heart disease, metabolic syndrome, Alzheimer’s disease, Dementia, PCOS, epilepsy and for those wanting to lose weight.
If you have any sort of medical condition, speak with your doctor before starting a ketogenic or any new diet.
Essentially, the way it works is to restrict the number of carbs each day to 20 to 50 grams (0.7 to 1.8 ounces). I’ve included a list of ‘keto friendly’ foods and their carb content below.
Different types of ketogenic diets
There are four commonly used versions of the ketogenic diet:
- Standard ketogenic diet (SKD): This is a very low-carb, modest-protein, and high-fat diet, typically 75% fat, 20% protein and only 5% carbs.
- Cyclic keto diet (CKD): This diet has periods of higher-carb days, such as 5 ketogenic days and 2 high-carb days per week.
- Targeted keto diet (TKD): This diet allows you to add carbs around workout times.
- High-protein keto diet: (HPKD) Like the standard ketogenic diet but has more protein. The ratio is usually 60% fat, 35% protein and 5% carbs.
However, only the standard and high-protein ketogenic diets have been studied extensively, with the cyclical or targeted ketogenic diets often used by bodybuilders or athletes. Some athletes use the standard or high protein version to get their body into the shape they desire, then use the carb load days for events.
The information in this article mostly applies to the standard ketogenic diet (SKD), but many of the principles also apply to the other versions.
Research shows that the ketogenic diet is far superior to the low-fat diet styles of weight loss programs. What’s more, the diet is so satisfying that you can lose weight without thinking about calories. The main focus is to keep carbohydrates low. People on a keto diet generally lose more weight than those who use a low-fat, low-calorie type diet.
Good for those with diabetes and pre-diabetes
Diabetes is characterized by changes in metabolism, high blood sugar and impaired insulin function. The ketogenic diet can improve insulin sensitivity by as much as 75% and be a great aid to losing weight. Fat loss can lead to dramatic improvements for Type 2 diabetics and pre-diabetics. Many people with Type 2 diabetes have even been able to stop their medication (only under the guidance of their doctor).
Supports neurological diseases like epilepsy
The ketogenic diet was originally developed by Dr Russell Wilder in 1921 to treat children with drug-resistant epilepsy. Dr. Wilder’s diet provides around 90% of calories just from fat which is said to mimic the beneficial effects of starvation on seizures without starving at all. How this has its anti-seizure effects is unknown at this point, but it has shown very promising results for many people who have been unresponsive to drug therapy. Studies have shown that the keto diet can create a massive reduction in seizures for many epileptic people, especially children.
Although the keto diet can be very effective for reducing seizures in many people, it does require close supervision by a neurologist and shouldn’t be undertaken without a medical recommendation first.
Support for Alzheimer’s disease
Research is still in the early stages but some believe that Alzheimer’s disease should be considered a ’Type 3’ diabetes because the brain’s cells become insulin resistant and are unable to use glucose properly, leading to inflammation in the brain. One theory is that ketones protect our delicate brain cells from free radicals, also known as reactive oxygen species, which are by-products of metabolism that can cause inflammation. Another theory is that a high fat diet can reduce the harmful proteins that accumulate in the brains of people with Alzheimer’s.
Support for those with heart disease & metabolic syndrome
The ketogenic diet can help to improve risk factors like body fat, triglyceride and HDL cholesterol levels, blood pressure and blood sugar levels. There are many factors that explain the dramatic positive effects of ketosis on markers of metabolic disease – mainly there are less carbs, a decrease in insulin resistance, plus the addition of healthy fats which help to reduce inflammation. The diet also promotes fat loss around the abdomen. Each of these helps to lower the risk of heart disease and metabolic syndrome.
Cancer treatment support
The ketogenic diet is currently being used to treat several types of cancer and to slow tumour growth. There is still much research to be done in this area of health, so only go on a ketogenic diet if recommended by your practitioner.
Polycystic ovary syndrome
The ketogenic diet can help reduce insulin levels, which may play a key role in PCOS – polycystic ovary syndrome treatment.
When on a ‘Keto Diet’ your brain gets its energy via two separate processes called ketogenesis and gluconeoegenesis.
Ketogenesis – aka Ketosis
Glucose, the sugar in your blood, is usually the brain’s main fuel source. Unlike muscle, your brain can’t use fat as a fuel source, but it can use ketones. These ketones will be produced in your liver from fat when the glucose and insulin levels drop, which actually happens whenever we go many hours without eating, such as overnight.
The liver will increase the production of ketones during fasting, intermittent fasting, or when our carb intake is below 50 grams per day. These ketones will provide up to 70% of the energy required for the brain, the rest comes from the minimal carbs eaten.
Although most of the brain can use ketones, there are portions of the brain that require glucose to function. On a very-low-carb diet, some of this glucose can be supplied by the small amount of carbs consumed and the rest comes from the process called gluconeoegenesis, which means ‘making new glucose’.
The liver creates glucose for the brain by manufacturing the glucose using amino acids from protein, and because the keto diet has adequate protein, the fuel for this process is there. The liver can also make glucose from glycerol, the body’s storage form of fat.
Ketogenesis, Ketosis and gluconeogenesis are perfectly capable of fulfilling the brain’s energy needs. Ketosis is NOT the same as Ketoacidosis. People often confuse ketosis and ketoacidosis. Ketosis is a normal healthy metabolic response, but ketoacidosis is a very dangerous condition that can be fatal if left untreated.
Ketoacidosis is where the blood is flooded with very high levels of glucose (blood sugar) as well as ketones which makes the blood too acidic, which is seriously dangerous. Ketoacidosis is common with poorly managed Type 1 diabetes, but can also occur in people with Type 2 diabetes, although it is less common.
People respond to ketogenic diets in different ways. For some people there are adverse effects, although most occur for a short period of time during the settling in phase of the diet and usually disappear after a few weeks. If you are unsure about any symptoms, please check with your health care provider.
Some people experience elevated cholesterol and triglyceride levels which is normally temporary and then levels usually normalise or even improve over the prior levels before the diet started.
Kidney stones are an uncommon occurrence that has affected some children on a ketogenic diet for epilepsy but has usually been well managed with consumption of supplemental potassium citrate.
Probably the most common symptom of a ketogenic diet, but high amounts of fats will usually soften stools after a little while. Drinking plenty of water and making minor adjustments in the amount of carbs, such as including more fibre foods such as psyllium or chia seeds, can help this. Magnesium supplements or extra vitamin C powder can also help to alleviate constipation in more stubborn cases.
When you first start a ketogenic diet, you may get a few headaches, feel tired, or lightheaded for a few days. This is termed the ‘keto flu’. To avoid it drink at least 68 fluid ounces/2 litres of water per day.
It is also good to add 1–2 grams (¼ tsp) of salt each day to replace the amount lost in your urine when carbs are reduced. Drinking vegetable or bone broth will help to increase the salt and fluid needs. Supplementing with potassium and magnesium can also help. Only have salt if it is OK for your body – check with your doctor.
During the first week or so while adjusting to the new diet, don’t exercise heavily until you feel ready.
People often report bad breath with the keto diet, which is caused by elevated ketone levels that tells you that you are on track with the diet. The cause of the bad breath is acetone, a ketone that is in your urine and breath. You can brush your teeth and use a mouth wash several times a day but be assured that the bad breath will go away after about 2-3 weeks and is not permanent.
Fruity smelling urine
This is due to the excretion of by-products created during ketosis, which is similar to the breath situation and will clear.
One big issue for many ketogenic dieters is lack of sleep, especially when they first change their diet. Many people report insomnia or waking at night when they first reduce their carbs drastically. This usually disappears in a matter of weeks then many find they sleep better than before.
When you first switch to a ketogenic diet, one of the biggest issues may be initial weakness and fatigue as it can take a while for the body to get used to getting its energy from fat instead of carbs after decades of running on a carb heavy fuel system. This can make many people quit the ketogenic diet prematurely before it has a chance to fully ‘kick-in’ and give you the benefits.
To help reduce this fatigue increase your electrolytes. Electrolytes are often lost because of the rapid reduction in your body’s water content and many of the foods you have eliminated may have contained salt.
When using electrolyte supplements try to obtain 2,000–4,000 mg of sodium, 1,000 mg of potassium, and 300 mg of magnesium, per day. Check they don’t contain any carbs. Beware of electrolytes that add sugar or fructose (many do, especially sports drinks).
Short-term decreased exercise performance
Similar to the above, removing carbs can lead to general tiredness which includes an initial decrease in exercise performance. This is primarily caused by the reduction in your muscles’ glycogen stores, which provide the main fuel source for all forms of high-intensity exercise.
After several weeks, many keto dieters say their performance returns to normal, with the added benefit of an increased ability to burn more fat during exercise.
- Any food that is high in carbs should be limited
- Sugary foods: soda/soft drinks, fruit juice, smoothies, cake, ice cream, candy/lollies, or anything with sugar, sugar derivatives and most sweet things
- Grains or starches: any grain foods such as bread, rice, pasta, cereal, etc
- Fruit: all fruit, except small portions of berries like strawberries
- Beans or legumes: peas, kidney beans, lentils, chickpeas, etc
- Root vegetables and tubers: potatoes, sweet potatoes, carrots, parsnips, beetroot/beets plus other starchy vegetables such as pumpkins/squash and corn
- Diet products/low fat: these are highly processed and often high in carbs
- Condiments or sauces that contain sugar and/or unhealthy fat
- Unhealthy fat: processed or heated vegetable oils, mayonnaise (home-made ok)
- Alcohol can throw you out of ketosis due to its sugar/carb content
- ‘Sugar-free’ diet foods commonly contain sugar alcohols, which can affect ketone levels. Some are also highly processed
- Beef, lamb, pork, chicken and turkey
- Fish such as salmon, trout, tuna, sardines and mackerel
- Eggs, preferably pasture raised or organic
- Nuts and seeds: almonds, pecans, flaxseeds, pumpkin seeds, chia seeds (small amounts)
- Healthy oils: primarily extra virgin olive oil, coconut oil and avocado oil
- Avocados, unsweetened coconut cream (no additives)
- Condiments such as salt, pepper, fresh or dried herbs and spices
- Low-carb veggies such as asparagus, broccoli, Bok Choy, Brussels sprouts, cabbage, cauliflower, celery, cucumbers, tomatoes, mushrooms, onions, peppers, zucchini (small amounts)
- Herbs such as cilantro/coriander and parsley (dried herbs and spices are good too)
Healthy ketogenic snacks
- A handful of nuts or seeds
- Hard-boiled eggs
- 90% dark chocolate, cacao nibs, cacao, creamed coconut
- A low-carb shake with almond or coconut milk, cocoa powder and nut butter
- Coconut yogurt mixed with nut butter and cocoa powder, or strawberries or raspberries
- Strawberries and unsweetened coconut cream
- Small portions of leftover meals
- Snacks using cucumber sticks, celery sticks and a few carrot sticks, dipped into avocado guacamole makes a great snack that is low carb
- Coffee made on cow’s milk, has 18 grams of carbs per 16oz/470ml. Maybe have your coffee black or with unsweetened coconut cream
- Mix unsweetened cacao powder (1Tbs = 3g carbs) with chia seeds (2Tbs = 2g carbs) and coconut milk (1 cup = 1 to 3 grams carb), then add some water as it thickens. It’s a very filling and yummy snack or breakfast with around 8 grams of carbs in total. Topped with a few raspberries and chopped pecan nuts makes it around 10 grams of carbs. So worth it. 🙂
- Garlic bread made with almond flour, egg, coconut oil and garlic are around 1 to 3 grams of carbs per slice depending on the size.
Tips for eating out on a ketogenic diet
It is not very hard to make most restaurant meals keto-friendly when eating out. Many restaurants offer a meat, chicken, or fish-based dish which you can have with vegetables or salad. Egg-based meals are also a great option such as an omelette or eggs and bacon (without the toast).
Another favourite is bun-less burgers – omit the bun, swap the fries for salad vegetables, add extra avocado, bacon, or eggs.
Under each food group below is the carb content for a variety of foods you can choose for the ketogenic diet. Keep in mind that some of these foods are high in fibre, so sometimes the digestible ‘net’ carb content is even lower.
Aim for 20 to 50 grams/0.7 to 1.8 ounces of carbs a day
The following foods show the amount of carbs in grams or ounces per 100g/3.5oz of food. To work out your daily carb content, you need to weigh the food, then work out how many grams or ounces of carbs.
Most protein foods contain negligible carbs
- Eggs – almost zero carbs
- Meats and Poultry: all types of meat and poultry are almost zero carbs. Exceptions are organ meats like liver, which are about 5% carbs (5g carbs per 100g)
- Fish – almost zero carbs. Exceptions are shellfish (5g carbs per 100g)
- Tofu – 1.9g per 100g, tempeh is 9g per 100g serve (see other vegan proteins in legumes section below)
Most vegetables are low in carbs. Leafy greens and cruciferous vegetables are very low (with most of their carbs from fibre) which means they are not as high as their given values.
Starchy root vegetables like potatoes and sweet potatoes are high in carbs as are corn and pumpkin, so they are best avoided. Values are per 100g unless otherwise stated.
- Lettuce, any variety – 2 g/0.04oz
- Carrot – 7g/0.25oz
- Beetroot/beets – 7g/25oz
- Parsnip – 13g/0.46oz
- Potato – 15g/53oz
- Sweet potato – 17g/0.60oz
- Pumpkin – 7g/0.25oz
- Peas – 9g/0.32oz
- Corn – 15g/0.53oz
- Broccoli – 4g/14oz
- Tomatoes – 3g/0.11oz
- Onions – 7g/0.25oz
- Brussels Sprouts – 5g/18oz
- Cauliflower – 4g/0.14oz
- Kale – 4g/0.14oz
- Eggplant – 3g/0.11oz
- Cucumber – 3g/0.11oz
- Bell Peppers/capsicum – 4g/0.14oz
- Asparagus – 2g/0.04oz
- Green Beans – 6g/21oz
- Mushrooms (6) – 3g/0.11oz
- Celery – 1g/04oz
- Spinach – 1g/0.04oz
- Zucchini – 3g/0.11oz
- Swiss chard – 1g/0.04oz
- Cabbage – 3g/0.11oz
Legumes, pulses and grains
Note: it is very difficult for a vegan to stay in ketosis due to the high carb content of these meals, however here’s a guide of the carbs in many vegan proteins.
Intermittent fasting can help you to have periods of ketogenesis while in the fasting state, but generally not during the eating phase because it’s too hard to get the carb values low enough to stay in ketosis.
Values are per 100g unless otherwise stated.
- Lentils – 12g/0.42oz
- Corn – 15g/0.53oz
- Backed beans – 16g/56oz
- Quinoa – 18g/63oz
- Rice (cooked) – 28g/0.99oz
- Chickpeas – 61g/2.15oz
- Kidney beans – 60g/2.12oz
Fruits and Berries
Most fruits are high in carbohydrates compared to vegetables so depending on how many carbs you are aiming for, you may want to restrict your fruit intake to 1-2 pieces per day.
However, this does not apply to fatty fruits like avocados or olives. Low-sugar berries, such as strawberries or raspberries are also excellent. Values are per 100g unless otherwise stated.
- Avocado – 8.5g/0.30oz (13g/0.46oz per cup). The majority (about 78%) of carbs in avocado are fibre, so the digestible ‘net’ carbs are negligible.
- Olives – 6g/0.21oz
- Strawberries – 8g/0.28oz (or 11g/39oz per cup)
- Blueberries – 14g/0.5oz
- Grapefruit – 11g/0.39oz (13g/0.46oz in ½ grapefruit)
- Apricots – 11g/0.39oz (8g/0.28oz in 2 apricots)
- Lemons/limes – 6g/0.21oz
- Kiwi fruit – 12g/0.42oz
- Mulberries, blackberries – 5g/0.18oz
- Raspberries – 5g/0.18oz
Nuts and Seeds
Nuts and seeds are very popular on low-carb diets. They tend to be low in carbs, but high in fat, fibre, protein, and various micronutrients. Nut flours and seed flours, such as almond flour, coconut flour and flax seed meal are often used to make low-carb breads and other yummy baked foods. Values are per 100g unless otherwise stated.
- Almonds – 22g/0.77oz
- Walnuts – 14g/0.49oz
- Peanuts – 16g/0.56oz
- Pecan nuts – 4g/0.14oz
- Hazelnuts – 7g/0.25oz
- Macadamia nuts – 5g/0.18oz – These are the one of the lowest carb nuts (apart from pecans) but also the highest fat content nut, so they are great for a keto snack
- Cashews – 27g/0.95oz – Very starchy and generally not recommended
- Coconuts – 6g/0.21oz
- Pine nuts – 7g/0.25oz
- Pistachios – 18g/0.63oz
- Flax seeds – 29g/1.02oz
- Pumpkin seeds – 11g/0.39oz
- Sunflower seeds – 20g/0.70oz
- Sesame seeds -23g/0.81oz
- Sacha Inchi seeds – 12g/0.42oz
- Chia Seeds – 44g/1.55oz – These are extremely high, but 86% of the carbs are fibre, so in reality they contain very few digestible ‘net’ carbs (around 8g/0.28oz per 100g/3.5oz which is a lot of chia seeds. The fibre content is great to keep your bowels regular. You would normally use only about 2Tbs chia seeds, which is only 2g/0.07oz of carbs. Yippee!
Fats and Oils
There are many healthy fats and oils that are acceptable for a ketogenic diet. Many are in some of the above foods such as the nuts and seeds, avocado, meats, and fish. The added healthy oils below all have zero carbs. Coconut and animal fats are the best for cooking due to their high heat stability. If using low or no heat, then any oil is fine provided it is good quality.
- Olive Oil
- Coconut Oil
- Duck Fat or any animal fat
- Avocado oil
Fruit juices and soft drinks/sodas are very high in sugar and carbs and should definitely be avoided.
Water, black tea, and black coffee, have zero carbs, as does soda water or carbonated mineral water. If you don’t like your coffee or tea black, then coconut cream works well.
Herbs, Spices and Condiments
There are heaps of great tasting herbs, spices, and condiments you can eat. Most are very low in carbs, such as salt, pepper, garlic, ginger, cumin, coriander, parsley, cinnamon, mustard and oregano etc.
Probably one of the hardest things about the ketogenic diet is to get your head around the changes in how your body will get its fuel, and the consciousness around needing carbs in your diet.
Some scientists say that provided we get our protein and fats, then we don’t have to have carbs. I do not agree with a zero-carb diet, but around 50 grams daily is a nice level for health benefits.
Admittedly this diet is not for everyone, but if you have certain health conditions that warrant a Keto Diet, you will need a commitment of at least four weeks for your body to settle as you get used to this new way of eating.
From that point on, your commitment will be easier as you begin to see the desired results and want to keep eating this way. Many ask if it is healthy to cut a lot of carbs from the diet. There are two answers: ‘yes’ and ‘no’.
If you need this diet to support your body and make sure that you get your vitamins, minerals, and antioxidants by choosing plenty of low carb vegetable and salad options, then the answer is a definite ‘yes’.
But if you only eat proteins and fats and try to sneak in a few carbs from rubbish food, then this is not a healthy diet for you.
If you have trouble digesting fats, such as those with gallbladder issues, or you get diarrhoea from the fats, you will need to increase your proteins a little and decrease fats until you find a comfortable level.
The carb value you decide to use will also depend on your symptoms and reactions. For example, if someone has strong side effects, they may be better off increasing carbs to say, 50-80g (1.75-2.82oz) per day. Whereas 20g (0.7oz) of carbs a day might work better for someone trying to alleviate uncontrollable epilepsy, where less carbs are better.
It is important to speak with an integrative doctor or qualified health practitioner to guide you through the best form of this diet to suit your needs. Also, do not do this diet unsupervised if you have any health conditions.
Before you commence your diet, see your medical or health care professional for qualified guidance about what foods and supplements are best for your body. While on the diet do not stop any medications or supplements previously prescribed unless advised otherwise by your medical or health care professional.
During the early stages of a new diet, you may experience symptoms such as fatigue, headaches, or body aches, which may occur because your body is detoxifying. However, if you are unsure about a symptom at any time, check immediately with your medical or health care professional.
Client name and identifying information changed
I could never claim that a ketogenic diet clears anyone of terrible conditions like epilepsy, but when a desperate mother of a 26-year-old girl (who had epilepsy for the previous two years) came to see me because she had tried every drug and therapy available for her daughter and nothing worked, I decided to see how I could help in any way.
Apparently, April was a totally fine, healthy young lady without a care in the world, then one day she just started getting seizures. April had been to many doctors and specialists and had lots of tests and scans. The tests confirmed their fears that she had epilepsy, but every drug they tried didn’t help and her seizures were getting worse over time.
Totally house bound by this stage, we spoke via Skype as April couldn’t leave the house as she feared a sudden seizure could break her body again. Every time she had a seizure she would suddenly drop to the floor and frequently break a bone, so she had to be in a ‘safe place’ most of the time.
I made recommendations of some good oils and nutrients reported to help with epilepsy as well as pyrrole disorder. But I had also researched the effectiveness of the ketogenic diet which I shared with April and her mum.
They were willing to give it a go as they certainly had nothing to lose by trying it. Along with ketogenic, the diet was also gluten and dairy free to reduce other potential compounds that may have been affecting her.
After about six weeks on a very low carbohydrate diet with high amounts of good fats/oils, including some supplemental ones, April and her mum noticed that the number of seizures per day had dropped by about 50% and the duration of the seizures was less. This was by no means a cure, but it all helped.
A few months later, they contacted me and said they were trialling a new drug which seemed promising at that point, and the specialist also recommended that April stay with the diet as he felt hopeful that the combination of the new drug and the diet would have a positive effect.