The ketogenic diet is probably one of the most talked-about eating plans right now. It is also one of the most controversial, having just as many critics as it does supporters.
Commonly referred to as the keto diet or just keto, it shares some similarities with the Atkin’s diet and other low-carb diets. It involves drastically reducing carbohydrate intake and replacing it with fat.
Many studies show that this diet can help you lose weight and improve your health; however, it is certainly no walk in the park.
So let’s take a further look.
What Is a Ketogenic Diet?
The ketogenic diet is a high-fat, moderate protein, low carbohydrate diet. It involves reducing carbohydrate intake to just 20-50g, or less than 5 per cent of your total caloric intake, and replacing it with fat.
When fat provides most of the fuel for the body, it enters a metabolic state called ketosis, from which the diet derives its name. During ketosis, your body produces ketone bodies from fat to use for energy instead of glucose from carbohydrates.
So what can you eat on a ketogenic diet?
Here’s a rough guide on the kind of foods you can eat and which ones to avoid while following this type of diet.
What About Protein?
One common misconception about a ketogenic diet is that you can eat as much protein as you like; this is not the case. Along with restricting carbohydrates, you also have to keep your protein intake moderate.
The body can convert protein into glucose through a process called gluconeogenesis. This process is essential during ketosis as it provides the body with the glucose it still needs to function. However, overeating protein can increase glucose levels and take you out of ketosis.
You may need to rethink your ratios of protein and fat on a ketogenic diet. Think a small piece of protein alongside a generous portion of fat rather than the other way around.
That being said, you also don’t want to have too little protein. Your aim should be to stay in ketosis without sacrificing lean body mass if you lose weight. Aim to keep your protein intake between 1.2 to 1.8 g of protein per kilogram of body weight.
One of the best protein sources on a keto diet is fatty fish (like salmon or mackerel). It offers a source of heart-healthy protein and omega-3 fatty acids. Eggs are another excellent choice; one large egg contains 6g of protein and 5g of fat.
Foods You Can Eat.
Protein – meat (preferably grass-fed), seafood (especially fatty fish), poultry, eggs, tofu (in moderation)
Full-fat / high-fat dairy – cheese, cream, butter, but not milk
Healthy Fats – olive oil, coconut oil, nut or seed oils
Nuts and seeds – in moderation, unsweetened almond milk
Low-carb vegetables – leafy greens, lettuce, mushrooms, zucchini, broccoli, eggplant, asparagus, leeks, cabbage, capsicum
Some fruits – avocado, tomatoes, olives, lemons, limes, berries (in moderation)
Drinks – water, black tea, black coffee
Foods to Avoid.
Grains (including rice, pasta and bread)
Refined carbohydrates (cereals, chips, pastries)
Sugars or lollies
Starchy vegetables (such as potatoes, carrots, parsnips and other root vegetables).
Types of Ketogenic Diets
There are several versions of the ketogenic diet which are listed below. The standard version is the most researched and most recommended.
The standard ketogenic diet (SKD):
This is a very low-carb, moderate-protein and high-fat diet. It typically contains 75% fat, 20% protein and only 5% carbs.
High-protein ketogenic diet:
This is similar to a standard ketogenic diet but includes more protein. The ratio is often 60% fat, 35% protein and 5% carbs.
The cyclical ketogenic diet (CKD):
This diet involves periods of higher-carb refeeds, such as five ketogenic days followed by two high-carb days.
The targeted ketogenic diet (TKD):
This diet allows you to add carbs around workouts.
Keep in mind that most studies on ketogenic diets focus only on the standard and high-protein diets. Cyclical or targeted ketogenic diets are more advanced methods primarily used by bodybuilders or athletes.
Benefits of the Ketogenic Diet
One of the main reasons many people start a ketogenic diet is for weight loss. Many studies have shown that keto is an effective way to lose weight and lower risk factors for certain diseases. The benefits of a ketogenic diet are similar to other low-carb diets, but it appears to be more powerful.
When starting a ketogenic diet, You will likely slim down, and it will probably be fast. Research shows that the ketogenic diet is far superior to the often recommended low-fat diet for weight loss, and it has a high success rate. Some studies found that people lost up to 3 times more weight on ketogenic diets than calorie-restricted low-fat diets.
The diet causes your body to use fat for fuel, mobilising it for use as energy, leading to a significant body fat reduction. Substantial reductions in levels of insulin, the fat-storing hormone, also help to reduce body fat.
Ketosis may also increase metabolism; however, many of the weight loss benefits come from the fact that you likely won’t be as hungry. Through the higher satiating effects of fats and proteins, the ketogenic diet helps decrease your appetite. It helps you lose weight without counting calories or tracking food intake.
Along with weight loss, people following a ketogenic diet often experience other benefits such as:
Increased energy and mental performance:
Many people following a ketogenic diet notice an increase in focus and concentration and improved mental clarity. Some people use ketogenic diets specifically for this reason.
During ketosis, your brain doesn’t need dietary carbohydrates. Its primary fuel is ketones and a small amount of glucose synthesised in the liver. The steady flow of energy to the brain this produces means you don’t get the spikes and crashes sometimes associated with diets high in refined carbohydrates.
A calmer Stomach:
Some people with irritable bowel syndrome (IBS)who follow a ketogenic diet report having a calmer stomach, less gas, fewer cramps and less pain. The diet can improve IBS symptoms fairly quickly and is the main benefit for some people of following a ketogenic diet.
Increased physical endurance:
Some people experience an increase in physical endurance when following a ketogenic diet.
Although the body’s fat stores are not its preferred energy source, they contain a substantial amount of energy. When your body is in ketosis, it becomes much more efficient at using these fat stores for energy.
Energy from glucose and glycogen stores can only last up to a couple of hours of intense exercise before being depleted. In contrast, the energy contained in your fat stores can potentially last for weeks.
People following ketogenic diets often report a decrease in acne. The acne improvements may be caused by lower insulin levels and from eating less sugar or processed foods.
Benefits Backed by Science
The ketogenic diet has been the focus of many scientific studies looking at the various benefits derived from following such a diet.
Initially, the diet was formulated as a tool for treating neurological diseases such as epilepsy. Studies on the ketogenic diet now show that it has benefits for a wide variety of different health conditions:
The ketogenic diet can improve cardiovascular disease risk factors such as body fat, HDL cholesterol levels, blood pressure, blood glucose and insulin levels.
Type 2 diabetes:
The substantial decrease in blood glucose and insulin levels significantly decrease the risks for type 2 diabetes. Improvements in insulin sensitivity and reductions in body fat also reduce the risk.
Studies show that ketogenic diets can help manage type 2 diabetes, sometimes even leading to complete reversal of the disease.
The diet is currently being used to treat several types of cancer and slow tumour growth in various studies.
The ketogenic diet may reduce symptoms of Alzheimer’s disease and slow its progression.
The ketogenic diet is a proven medical therapy for epilepsy used since the 1920s. Research shows that it can cause massive reductions in seizures in epileptic children and allow for some to take fewer, or no, anti-epileptic drugs.
One study found that the diet helped improve symptoms of Parkinson’s disease.
Polycystic ovary syndrome:
The ketogenic diet can help reduce insulin levels, which may play a key role in polycystic ovary syndrome.
One animal study found that the diet can reduce concussions and aid recovery after brain injury.
Keep in mind that research into many of these areas is far from conclusive. It might sound like a keto diet is a miracle cure for anything. It’s certainly not. While it can have many benefits, it’s not for everyone.
Who Should be Careful or Avoid it?
Like many diets, the ketogenic diet is not a cure-all magic pill.
Despite its tempting weight-loss promises, there are people with certain conditions for which the ketogenic diet is not suitable. People with the following conditions should steer clear of a ketogenic diet:
Disorders of fat metabolism
Pyruvate kinase deficiency
If you have underlying health issues, even if not mentioned here, it’s always advised to see a doctor or registered dietitian before switching up your diet.
Vegetarians and vegans may struggle with this diet type because of the key role meats, eggs, fish and dairy play.
Pregnant or breastfeeding women should avoid this diet.
A ketogenic diet is probably not the best option for elite athletes or those wishing to build large amounts of muscle.
No single diet is suitable for everyone. Individual metabolism, genes, body types, lifestyles, taste buds, and personal preferences differ from person to person.
Most research conducted into the keto diet looks at its short-term benefits. There has not been much research into the long-term effects of this diet.
Some of the possible long-term risks associated with this diet are kidney or liver problems. Animal studies highlight potential problems such as non-alcoholic fatty liver from long-term adherence to the diet. Even though these are animal studies, they highlight the need for further research into this diet’s long-term implications on humans.
Some studies point out that the claimed health benefits of the ketogenic diet are controversial. There appears to be conflicting research on whether the ketogenic diet helps or harms people with heart conditions or type 2 diabetes.
Dehydration is also a risk while following this diet, so it is essential to consume plenty of fluids, especially water.
The diet doesn’t get rave reviews from many health and medical experts around the world. In 2019, the ketogenic diet was ranked 38/41 in a list of best diets overall, judged by a panel of medical experts. Some of the reasons for this ranking are that the ketogenic diet cuts out many foods such as fruit and whole grains, generally correlated with heart health and diabetes prevention.
Many experts agree that this is not a good diet to follow long-term. However, entering ketosis via diet does not have any real negative short-term consequences. Putting your body into ketosis for a limited time is likely not harmful.
The ketogenic diet can be tough to start. It is likely a radical departure from the way you’re eating now. People starting a ketogenic diet generally experience a transition period. During this period, the body is switching from glucose as its primary fuel source to utilising fats as fuel.
Many people describe flu-like symptoms during this period, often referred to as the ‘Keto Flu’. Characteristic symptoms of the keto flu are lethargy, fatigue and a decreased mental function. There may also be some other adverse effects such as increased hunger, sleep issues, nausea, dizziness, digestive discomfort, and poor exercise performance.
The keto flu symptoms usually begin within the first day or two after removing or restricting carbs in the diet. Symptoms will generally last up to a week until your body adapts to increased fat burning, but it can last up to one month in extreme cases. Some people never experience these symptoms at all.
One explanation for these symptoms is the excess fluid and sodium excreted by the body during ketosis. This excretion can result in dehydration and reduced sodium levels. Ensuring you drink plenty of water and add salt to your food can be one way to minimise the initial effects.
When starting this diet, it is wise to pick a start date that is not full of deadlines and obligations. Preferably a slower time when you can rest as needed. You may also want to take it easy with exercise during the first week or two as your body adjusts to burning more fat rather than carbs for fuel.
Gradually decreasing carbohydrate consumption over weeks may help reduce potential side effects. Still, with a slower start, you’ll likely see slower results. While the short-term results may be slower, the long-term results should remain the same.
Tips for Starting
Know what foods you’ll eat and avoid on the ketogenic diet
Following a ketogenic diet, you will be severely limiting your carb intake and eating a lot more fat. To do this properly, you will need to know which foods contain mostly carbs, fat, and protein so that you can make the right choices.
When many people think of carbohydrates, they think of rice, bread, pasta, and other processed foods. However, these are not the only foods high in carbohydrates. Fruit and vegetables are also mostly carbohydrates. Beans and legumes may contain protein, but they’re also very high in carbohydrates. The only foods that don’t have any carbohydrates are meat and pure fats, like butter and oils (including olive and coconut oil).
Stock up on staples
Buy plenty of things like meat, cheese, eggs, oily fish, avocados, nuts, oils, butter and cream. These will now be the staples in your diet.
Also, be sure to have plenty of low-carb veggies. These will help provide you with essential nutrients and provide the fibre you will no longer be getting from other food sources like grains.
Examine your relationship with fat — keto involves lots of it
Most people are afraid to have much fat in their diet because they believe it causes heart disease and high cholesterol. If you’re scared of fat, a ketogenic diet won’t work for you.
Transitioning to a high-fat diet can be uncomfortable at first, and may cause stomach upsets initially. Making small adjustments to your diet can be one way to ease into the practice. Slowly start pushing out carbs and getting in more fat each day. Order a burger on lettuce leaves, substitute green veggies for fries. Instead of potatoes or rice with your meal, opt for a non-starchy vegetable. Start cooking with more oil.
Many old dieting habits won’t make sense on a ketogenic diet. Things like cooking a plain skinless grilled chicken breast or removing the fat from a steak will mean you won’t get enough fat in your diet.
Work on your cooking skills to make fresh food
Following a ketogenic diet properly will mean you need to plan and prepare your meals. Many processed foods are high in carbohydrates and are not suitable for a keto diet, and it can be hard to find low-carb meals when you’re on the go.
Many keto websites and cookbooks are available today to give you some inspiration for keto-approved recipes you’ll enjoy. Find some recipes you like so that you have some keto-friendly options for any occasion. Experiment until you find the ultimate keto diet for you.
Maintain your electrolyte balance
During ketosis, your kidneys excrete more water and electrolytes, particularly sodium. You may need to increase your electrolyte intake to ensure your body is getting adequate levels to function correctly.
You can increase your electrolyte intake by salting your foods, eating more leafy green vegetables and adding nuts and seeds to your diet. It is also essential to drink plenty of water to replace the extra fluid your body excretes.
Have an after keto plan
A ketogenic diet is generally not something you will follow forever. While some people stay on this type of diet, it is often only used for the short-term. Some people follow a keto diet a few times per year, while others will use it to lose weight and change their eating habits. Think about what you want from following the diet and what your long-term plan will be.
If returning to a standard western diet after following a keto diet, you will likely lose any health benefits and regain the weight you have lost. Aim to change your overall diet into a healthier way of eating. Eat less refined carbohydrates and increase your intake of natural wholefoods.
Talk to your family about your diet and your goals
When following a ketogenic diet, you are likely to be eating differently to other family members. You may need to communicate with your family to explain what you are doing, why you are doing it and how it will look. Having family members or people you’re close to onboard with what you are doing will make it easier.
Frequently Asked Questions
How do you know you’re in ketosis?
There are three ways to measure for ketones, telling you whether you are in ketosis. Blood ketone meters measure the amount of Beta-Hydroxybutyrate (BHB) in your blood. They are the most accurate measure for ketosis. You can also measure breath acetone concentration using a special breathalyser which is cheaper and less invasive.
Another way is to measure acetoacetate levels in your urine through the use of urine detection strips. Urine strips are not as accurate but are a readily available and cheap way to measure for ketosis during the early stages of a ketogenic diet.
One way to know if you’re in ketosis without these measures is through observation. Certain telltale signs help indicate that your body is in a state of ketosis. These include:
Dry mouth and increased thirst:
As your body excretes more water, you may notice increased thirst. You may also notice a metallic taste in your mouth.
Especially when starting, you may need to go to the toilet more often as your body excretes more water.
This is due to a ketone body called acetone escaping through your breath, often described as a fruity smell or similar to nail polish remover. This smell can sometimes also come from sweat when working out or noticed in your urine. It’s often temporary.
Other less specific signs include:
Many people experience a significant reduction in hunger on a keto diet.
After the initial effects of the “keto flu,” many people experience an apparent increase in energy levels. You may also experience clear thinking, a lack of “brain fog,” or even a sense of euphoria.
Is the keto diet safe to follow?
Including high amounts of fat in your diet may seem like an unhealthy way to eat. However, research on the ketogenic shows no real negative consequences when done in the short term.
Given the restrictive nature of keto, you may fall short of certain nutrients, and long-term studies are needed to assess its real impact. However, most experts agree that putting your body into ketosis for a limited time is likely not harmful.
How many carbs do you eat on a ketogenic diet?
The exact number of grams of carbohydrates will be different for everyone but is generally around 20 to 50 g per day. Many people following a ketogenic diet count “net carbs,” which is total carbs minus fibre. Fibre isn’t counted in the carbohydrate total because the body doesn’t digest it.
Either way, this is a meagre amount of carbs and requires careful planning. Eating a little fruit, starchy vegetables, sugary foods, or whole grains can easily kick you out of ketosis.
How do I track my carb intake?
With the increased popularity of this diet, there has been an increase in macro or carb-tracking apps available, making it easy to track carb intake accurately. You can also use these apps to track fat and protein intake. Find one that you like and works for you.
What can you drink on a ketogenic diet?
Water is the perfect drink, and coffee or tea is OK too. Ideally, use no sweeteners, especially sugar. A little bit of milk or cream in your coffee or tea is OK, but keep in mind that the carbs can add up quickly if you drink multiple cups in a day.
Bulletproof coffee is also a popular option and is one of the best keto-friendly drinks. Make this by mixing coconut or MCT oil and butter into your coffee.
The occasional glass of wine is fine too.
Can you drink alcohol on the keto diet?
Yes, you can consume alcohol in moderation on a ketogenic diet. Depending on the type, you may need to modify your carbohydrate from other sources on days that you drink alcohol.
A general rule to follow is the simpler, the better: Spirits are the best choice, followed by wine. If adding mixers to your drink, sugar-free soda or tonic waters are best and a slice of lemon or lime can add some flavour. You should avoid higher carbohydrate drinks like beer.
How much weight can you lose on the keto diet?
The ketogenic diet is a proven weight loss tool, and anecdotal reports of drastic transformations are easy to find. However, some longer-term studies found that although initial weight loss was more significant, there is little difference after 12 months compared to a conventional low-fat diet.
Just like any other diet, results will vary from person to person.
Some experts also note that, while the keto diet may lead to weight loss in the short term, the loss is unlikely to continue. Weight loss will slow down when approaching your normal body weight.
Can I eat fruit on the ketogenic diet?
Fruit is not a big part of the ketogenic diet. Fruit contains natural sugars and generally has too many carbohydrates to be included. You can have small amounts of lower-carbohydrate fruits such as berries and some citrus fruits like lemon and lime. Avocadoes and olives are also great fruits to include on a ketogenic diet because of their higher fat content.
Will the keto diet give me kidney stones?
The development of kidney stones is a concern when switching to a diet where you’re eating more protein. However, following a ketogenic diet properly requires a more moderate protein intake.
Also, consuming large amounts of red meat with inadequate fluid intake may increase the risk of stones. It is important to stay hydrated and replenish electrolytes (minerals like sodium, potassium, magnesium, and calcium) to minimise these risks.
How will the keto diet affect your cholesterol levels?
Experts often warn that eating excess saturated fat can raise cholesterol and increase the risk of heart disease. For that reason, many experts express concern that increased fat intake may be harmful to people who already have heart disease or have risk factors for it.
Even though you may be consuming more saturated fat, the interesting thing about keto is that it often leads to weight loss, which by itself can improve blood lipid levels. One study in obese patients on a keto diet found that after 24 weeks, total cholesterol levels dropped, “bad” LDL cholesterol decreased and “good” HDL cholesterol increased. Weight loss tends to lower cholesterol, even when paired with a high-fat diet.
Can the keto diet reverse type 2 diabetes?
Some preliminary research suggests ketogenic diets may be a good management tool for some people with type 2 diabetes. However, long-term studies are needed. Ketogenic diets can pose health risks to some people with diabetes, especially when following them without medical professionals’ supervision.
People on blood sugar lowering medication or those using insulin should be aware that drastically cutting carbs can lead to dangerously low blood sugar levels. This condition, hypoglycaemia, may lead to seizures, loss of consciousness, and blurred vision when not adequately addressed.
There is no consensus on whether keto is an effective dietary approach for diabetes. Further research is needed on this subject.
How long do you need to stay on keto to lose weight?
Many people report losing weight quickly on a ketogenic diet, and many studies support this. However, everybody is different. Your unique body chemistry dictates how you respond to eating this way. Aim to give it at least six weeks to see any meaningful results. After that, if you feel exhausted or hate eating the food, then the diet is probably not for you.
Many experts suggest spending no more than 3 to 6 months in ketosis because of the uncertainties of following it long-term and the risks of developing nutritional deficiencies. Remember that few long-term studies have looked at the effects of ketogenic diets on the human body.
To get the most out of a ketogenic diet, you must eat high-fat foods and limit your carbohydrate intake to 20 to 50 grams per day.
The ketogenic diet isn’t a miracle diet or a fix for all health problems. It is important to understand that keto, like all other diets, will not work the same for everyone.
The weight-loss benefits from following this type of diet are undeniable; however, for many, it is a fad diet that will offer only temporary results.
A ketogenic diet can be hard to stick to, and you need to think about how such a restrictive plan fits your lifestyle. There is also the risk of missing out on essential nutrients when following such a restrictive eating plan.
Nutrient deficiencies are a real possibility if following this type of diet for a long time. Long term research into ketogenic diets and their effect on the body is limited. More research is needed to determine how they may affect health and disease long-term.
Because it is generally not a long-term plan, you need to carefully manage your diet after stopping keto. When people go off keto and begin incorporating more carbs into their day, they often regain some weight. Some people may regain all the weight lost, and more if they return to their pre-keto eating habits.
If you have any underlying health conditions or any concerns always consult a medical professional before beginning a new diet such as keto.
AN IMPORTANT CAVEAT: I am not a medical practitioner or a dietitian. The information in this blog should be viewed as educational only.