Butter, bacon and cheese are in.
Toast, bagels and pasta are out.
Steak is the weekly dinner of choice and peanut butter is a go-to snack.
What the hell is going on?
Your friend’s been doing the Ketogenic (keto for short) diet and lost a bunch of weight eating everything but carbohydrate.
Maybe you’re tempted to see what it’s all about, but have a few questions first;
What is the Keto diet?
What are Ketones?
Can you still workout when doing it?
Can you do it wrong?
What are the benefits?
Is it good or bad for you?
If that’s the case, don’t worry, I’ve got you covered. In this article we’ll answer all your Keto questions and more.
Grab your coffee, add your butter, your oil and let’s go.*
What is the Ketogenic Diet?
The Ketogenic diet also commonly known as Keto or the Keto diet is a low carbohydrate, high fat diet.
There are 3 types of Ketogenic diet;
Standard Ketogenic Diet: where you eat 5% of your daily calories as carbs and then prioritise fat and protein intake to reach ketosis
Targeted Ketogenic Diet: like the above with the one difference being that you eat a small amount of fast-digesting carbs before your workout
Cyclical Ketogenic Diet: like the standard keto approach with the main difference being that once a week you eat a high carb diet to restore glycogen supplies
It’s called the Ketogenic diet because by severely reducing or eliminating your carbohydrate intake and replacing it with fat you force your body to switch from using glucose for energy to using fat instead.
This process is called ketosis.
For you to reach a state of Ketosis you need to clear your body of glucose (sugar from carbohydrate), you can do this in 2 ways;
Fasting: by not eating your body will naturally use it’s stores of glucose and switch to using fat for fuel. However, this effect will be reversed as soon as you eat carbohydrates
The Keto Diet: by eating a keto diet your body will switch to using fat for fuel and then remain in that state as you will not be eating (or eating very little) carbohydrate
In comparison to a ‘standard’ or ‘normal’ diet that includes a mix of all macronutrients (protein, fat and carbs) a Ketogenic diet has you eating fat and protein. When following the Ketogenic diet, it’s typical to eat less than 50g of carbohydrate a day.
Ketosis & Ketones
The whole point of the Ketogenic diet is to induce and then maintain a state of Ketosis.
Ketosis is a metabolic state where fat becomes your primary sources for fuel in the absence of glucose.
When this happens, your liver begins turning fat into ketones, these ketones become your primary energy source. Your body can get these Ketones in 2 ways;
Internal: your body can make ketones itself when you fast or if your remove carbohydrates from your diet
External: you can take a ketone supplement to boost your ketone levels, these are called “exogenous ketones” (more on this later)
The Ketogenic Diet & Weight Loss
Like with all diets the primary reason for weight loss is the maintenance of a calorie deficit over time. Any diet that restricts or removes a macronutrient will see an immediate reduction in food and therefore total calories consumed. (1)
A ketogenic diet is one way of doing this.
By cutting out carbs you will, in most cases, automatically eat less than you were before and be in a calorie deficit.
For this reason, the weight loss benefits of the ketogenic diet need to be viewed in the context of its ability to help you create and maintain a calorie deficit.
What it means is that the question isn’t “what’s better for fat loss, the keto diet or a moderate/high carb diet?” …existing research already shows there is no statistical difference between the two. (5, 6, 7, 8)
Instead the question is “which diet will help me not only lose fat, but sustain the fat loss over time?”
The reason for this is because both protein and fat take longer to be broken down and digested by the body which means you feel fuller for longer and more satisfied after meals.
This is obviously hugely beneficial when it comes to hunger management and overall calorie control.
The ketogenic diet may also be superior at decreasing fat storage and increasing fat burning, which could reflect an improvement in your ability to create a calorie deficit when using a ketogenic diet. (10, 11, 12)
Additionally, there is even some evidence that a ketogenic diet can suppress your appetite even after normal eating (i.e. higher carbs) has been reintroduced. (13)
All in all, the Ketogenic diet may offer some benefits when it comes to being able to create and maintain a calorie deficit. This is largely due to high levels of satiety after meals.
Note: it is possible to overeat on a Keto diet and gain weight. If you eat over your daily maintenance calories you will gain weight. This holds true for this and every other diet.
Health Benefits of the Ketogenic Diet
A ketogenic diet and ketosis may have various other health benefits outside of being a potentially powerful weight loss tool.
Studies have shown possible links between ketosis and a variety of health conditions; (14)
Alzheimer’s disease: a ketogenic diet may have benefits for those suffering from Alzheimer’s disease (18)
Parkinson’s disease: a small study saw that after 28 days following a ketogenic diet symptoms of Parkinson’s disease improved, however more research is needed to know the true effects (25)
Note: always consult your doctor before switching diets or trying something new.
Setting Up Your Ketogenic Diet
We’re going to discuss the standard ketogenic diet which is very low carb, moderate protein and high fat.
The first step is to calculate your calories based on your goal. There are several ways you could do this but here is the quickest;
Fat Loss: body weight in lbs x 12
Muscle Building: body weight in lbs x 14
Weight Maintenance: body weight in lbs x 16
Now, you know your daily calorie intake you need to adjust your macros to reduce carb intake and encourage a state of ketosis.
Macronutrient values vary but are typically around;
However, when training for to build strength and muscle or to retain muscle and lose fat it makes sense to shift protein a little higher to support these goals.
Therefore, when performing regular strength training it’s recommended your macros are;
Protein: 1g per lb of bodyweight
Fat: everything else
Once you’ve set up your diet the next step is to transition into ketosis and start reaping the benefits of a ketogenic diet.
How to Know if You’re in Ketosis
However, generally speaking most people can expect to reach ketosis in 2 – 4 days but it can take as long as 14 days. Ketones are measured in terms of millimole per litre in your blood and there are 3 stages you need be are of;
Regular dieting with carbs: 0 – 0.4 mmol/L
The ketogenic diet: 0.5 – 7 mmol/L
Diabetic ketoacidosis: 15 – 25 mmol/L
When you’re in ketosis you’ll be somewhere in that second range depending on your diet, if you’re fasting, whether you’re taking exogenous ketones and how long you’ve been in ketosis.
I’m sure you’re wondering what ketoacidosis is right now, so let’s discuss that.
Ketoacidosis is when the body produces too many ketones which then cannot be used and in turn make your bloodstream too acidic.
It’s a dangerous state to be in but only a concern for a small number of people. In particular, diabetics are at risk for developing ketoacidosis and should consult a doctor before starting a ketogenic diet.
As for how to tell if you’re in ketosis or not there are 4 ways to do this;
Urine strips: inexpensive and convenient but not always that accurate
Blood strips: effective at measuring ketosis but are expensive and inconvenient as you need to take a small blood sample each time you test
Breath meters: is supposedly fairly accurate but also quite expensive with many bits of equipment also having bad reviews
Physical symptoms: good indicators that you’re on the right track that are both free and reliable
The physical symptoms you want to look out for are;
Increased energy levels
The more of the physical symptoms you experience at the same time the more likely you are to be in ketosis. You could also couple looking for physical symptoms with inexpensive urine strips for a more accurate idea of your level of ketosis.
Ultimately, if you’re losing weight then it doesn’t really matter whether you’re actually in ketosis or not. After all, if your goal is to improve how you look and feel then weight loss is doing that.
Try not to panic too much about your exact levels of ketones and just track your progress and diet carefully and stay the course.
Should You Take Exogenous Ketones?
As we touched on earlier exogenous ketones are synthetic ketones supplements (not made in the body) that can be bought and consumed, most often as drinks.
They are usually taken to boost the effects of the ketogenic diet and have the following benefits;
Help you reach ketosis more quickly
Mitigate the side effects of keto flu
Can suppress your appetite
May support weight loss
Ketone supplements come in 3 main forms;
Ketone salts: also known as BHB salts these ketones typically come in powered form and are good for combating the effects of keto flu
Ketone esters: described as ‘raw’ ketones which metabolise quickly, they were primarily used for research purposes and tasted horrible but with the growth in popularity they are fast becoming available to the consumer
Ketone oils: can include MCT (medium chain triglyceride) oil and is used to boost ketone levels in the body, although MCTs need to be broken down before they can be used which means ketone oils may be less effective that salts or esters
Whilst exogenous ketones can help you transition into ketosis and minimise the effects of keto flu, they are not essential when doing the ketogenic diet. It’s also worth noting that as ketones can be used for energy, they contain calories in the order of about 4 calories per gram.
This means taking multiple exogenous ketone servings per day can add upwards of 200 calories to your diet.
Keto Flu: What is It & How to Manage It
By and large the ketogenic diet is perfectly safe for healthy individuals. However, it is common to suffer from some initial side effects as your body transitions from using glucose to using ketones for energy.
These side effects are commonly known as the ‘keto flu’ and can last for anywhere from a couple of days to a couple of weeks.
Whilst it’s possible to adjust with no side effects, most people experience some of the effects which include;
Reduced energy levels
Reduced mental function
Nasuea and vomiting
Digestive discomfort and stomach pains
Reduced exercise performance
Muscle soreness and cramps
Keto flu can be, at least an annoyance and at most downright awful. However, there are some steps you can take to manage the effects and transition to using ketones more smoothly.
Staying hydrated is general good practice for health, particularly when you lead an active lifestyle.
However, it becomes even more important when starting a keto diet as cutting out carbs can cause to rapidly lose water and increase the chances of you becoming dehydrated.
This is because glycogen (carbs stored in the body) draw water into the body and when you cut them out water is excreted as you use up your remaining glycogen stores.
Therefore, it’s common to see an initial, large drop in weight when starting a new diet, particularly one low in carbohydrate.
Reduce Exercise Volume
With fatigue, reduced performance and muscle soreness being common side effects of the keto flu, it can be wise to reduce the overall volume of activity whilst you adjust.
Although it’s common to continue weightlifting as you transition you should consider reducing the amount of volume you do and stop other activity like HIIT training whilst you adjust.
Low impact, low stress activities like walking and yoga can help keep you active and improve symptoms as you adjust.
Get Enough Sleep
When suffering from the keto flu its common to become more tired than usual as well as suffer from poor concentration and increased irritability.
It’s important to try and maintain a healthy sleep schedule as a lack of sleep can make the symptoms worse.
Make Sure You Eat Enough
As you transition to a low carb diet you may find yourself initially feeling hungrier and craving foods that are now off limits. It’s important that you ensure you’re eating enough fat and protein, as this will help reduce cravings and promote feelings of fullness.
Aim to hit your calorie goal and remember that fat is now your primary fuel source.
Reduce Carbs Slowly
For some people the side effects of keto flu can be numerous and debilitating. If you find yourself suffering, then you should consider slowly reducing the amount of carbs you eat.
Instead, of dropping carbs to 5% of your daily intake right away, try reducing it more gradually over several weeks.
Doing it like this can help smooth the transition and reduce your symptoms.
What to Eat When Doing Keto: Popular Keto Foods & Net Carbs
When doing a ketogenic diet, you need to be very mindful of your macronutrient intake, particularly carbohydrate and fibre as you can easily come out of ketosis if you eat too many carbs.
This is where net carbs come in. Net carbs are the total number of carbs that can be absorbed by the body and used for energy.
To figure out what this is you subtract the fibre (non-digestible carbs) amount from the total carb amount. For example;
Avocado has 17 g carbs and 13.5 g fibre which means net carbs are 3.5 g
Broccoli has 11 g carbs and 5 g fibre which means net carbs are 6 g
If we look at broccoli this means from 11 g of carbs, you will only digest and use 6 g for energy.
Counting your net carbs when following a keto diet has a few advantages and disadvantages;
More Dietary Freedom
Calculating your net carbs instead of total carbs may give you more flexibility when it comes to food choice. If you choose fibre dense foods, you can keep net carbs low and eat more before reaching your daily allowance.
Encourages Higher Fibre Intake
Fibre is a necessary part of the diet and by counting net carbs and being able to eat more fibre rich foods you ensure you’re getting enough.
Fibre also helps provide feelings of satiety.
Not Completely Accurate
Due in part to the way companies produce food labels it’s not always possible to completely accurately calculate net carbs. This may cause you to eat too much and come out of ketosis.
May Encourage Over Consumption
The keto diet world is full of “low in net carb” bars and snacks which are often full of sugar or artificial sweeteners which can knock you out of ketosis and/or lead to an over consumption of calories.
As for what you should eat to hit your macro and calorie goal when using the keto diet here is a rough breakdown of typical keto foods;
Meat: any meat fits the bill here, you can eat steak, chicken, turkey, bacon, sausages, ham, salami and more
Fish: fatty fishes are particularly good when eating keto, things like salmon, tuna, mackerel are all great
Nuts and seed: peanuts, almonds, walnuts, flax seeds, pumpkin seeds, chia seeds & more
Eggs and dairy: Eggs, milk, yoghurt are all good. As for cheese you want largely unprocessed items like cheddar, mozzarella, goat, cream or blue
Oils and butters: your go-to oils should be extra virgin olive oil, coconut oil and avocado oil. Nut butters are fantastic too
Vegetables: this includes avocados but mostly refers to cruciferous green vegetables like spinach, kale, broccoli, cauliflower and low-calorie vegetables like tomatoes, onions, peppers, etc…
Obviously, this list is not exhaustive, but it should good you a good idea of the types of foods you can eat when doing the ketogenic diet.
What Not to Eat When Doing Keto
Alright, we’ve look at what you can eat, now let’s turn our attention to what you can’t or shouldn’t eat. These are all the foods that will kick you straight out ketosis and mess up your diet.
Sugary foods: this includes things like soft drinks, fruit juices, smoothies, cakes, biscuits, ice cream, sweets, etc…
Fruits: Most fruit needs to be avoided due to its high sugar content however some fruits like berries are ok in small portions
Grains and starches: the list is a long one and includes pasta, bread, potatoes, rice, cereals, parsnips, white potatoes, couscous and more
Diet and low-fat products: these foods are often highly processed and contain a lot of carbs in replace of the fat which the opposite of what you want when doing keto
Beans and legumes: things like peas, kidney beans, lentils, chickpeas can all be high in carbs and should be avoided
Alcohol: most alcohols have a carb content that is too high and will knock you out of ketosis
Unhealthy fats: a good rule of thumb for any diet is to avoid unhealthy fats, particularly trans fats
Again, this list is not exhaustive but gives you a good starting point when planning your diet and what to eat.
Is Bulletproof Coffee* Good or Bad?
Bulletproof coffee (BPC) has become synonymous with the ketogenic diet, it promises to prevent hunger, increase satiety and kickstart your ketosis.
It’s meant to replace breakfast and the standard BPC consists of 2 cups of coffee, 2 tablespoons of grass-fed, unsalted butter and 1 – 2 tablespoons of MCT oil mixed together in a blender.
However, there are several potential downsides of regularly drinking BPC;
Bulletproof Coffee is Low in Nutrients
BPC is recommended in place of your usual breakfast each morning and whilst it provides you with plenty of fats which can help reduce hunger and provide energy when following a ketogenic diet, it is low in nutrients.
If you go from eating 3 meals a day to 2 meals and a BPC every morning, you’re essentially reducing your nutrient intake by a third. If not accounted for this can have an impact on your health over time.
Bulletproof Coffee is High in Calories
One of the big supposed benefits of BPC is that it helps with weight loss and fat burning but when you consider that those effects are minimal at most and that BPC is approximately 500 calories, it stops looking so amazing.
If you’re following a ketogenic diet in pursuit of a leaner, more toned body then starting your day with 500 calories of fat may not be the best approach, particularly if you’re struggling to hit your daily calorie goal and actually lose weight.
Bulletproof Coffee is High in Saturated Fats
BPC is very high in saturated fats and whilst the effect of saturated fats can be controversial it’s commonly believed that a high intake is associated with greater risk factors for many diseases and should be avoided. (29)
By consuming your daily saturated fat allowance (or close to it) in one go you may be putting yourself at risk, particularly if the rest of your diet is not nutrient-rich and balanced.
If you’re really set on having BPC every morning, then it’s advisable to see your doctor and get your blood lipids tested before you start.
Bulletproof coffee is not a magic bullet, in fact it’s a high calorie bullet that if you’re not careful will see you gaining weight not losing it.
Additionally, seeing as regular caffeine has also been shown to suppress appetite and help with hunger control why not just stick to your regular black coffee in the morning. (30)
Weightlifting & the Ketogenic Diet
We already know your performance will suffer as you adjust from using glycogen as your primary fuel source to using ketones instead, but how does this impact your ability to lift weights?
A while back in 2002 researchers looked at the effects of a six week low-carb diet on body composition in healthy, normal weight men. (31) The men were split into 2 groups;
Group #1: ate a ketogenic diet for the six weeks
Group #2: continued with their regular diet for the six weeks
At the end of the six weeks the researchers found that the keto group had gained just over 2 lbs of muscle, whereas the regular diet group had only gained 1 lb.
Which sounds significant, after all its double the amount of muscle in the same amount of time, that is until you look at the study a little closer.
Upon closer inspection of the study you’ll find that the keto diet group ate twice as much protein as the regular diet group, which on its own could account for the extra muscle mass gained during that period.
In addition to this the 2 groups didn’t follow the same workout plan instead they were left to continue doing whatever they were doing before joining the study. This could also be a reason for the difference in muscle mass gained.
So, not a particularly great study in favour of the ketogenic diet.
Now, more recently in 2017 there was a study aimed to measure the difference in muscle growth between ketogenic dieters and regular dieters. (32)
They again split their participants into 2 groups, except this time they got them to eat the same amount of protein and follow the same workout plan.
At the end of the 11 week study, the keto group were found to have gained roughly twice as much lean mass than the regular diet group and have larger gains in muscle thickness.
However, in a case of déjà vu this result only appears to support the ketogenic diet until you look closely at the way the study was conducted.
In the final week of the study the keto group had carb reintroduced to their diet and as a result gained 7 lbs. This means much of the increase in muscle size and lean tissue actually came from increase glycogen and water stores in the body.
This is supported by the fact that in the previous 10 weeks of the study, both the keto and regular diet group gained muscle at more or less the same rate.
This means the current logical conclusion is that there is not much difference between strength and muscle gained when on a ketogenic or ‘regular’ diet.
In other words, the ketogenic diet offers not advantage when it comes to weightlifting. However, there also isn’t any obvious disadvantage.
A study conducted in Brazil did a study with a group of overweight men and women who were split into 2 groups; (33)
Group #1: carb restricted keto-type diet
Group #2: regular moderate carb diet
Both groups lifted weights 3 times a week for 8 weeks and ate a similar amount of protein which was approximately 0.7 g per lb of bodyweight.
At the end of the study the results between the groups were very similar, with both groups getting stronger, losing fat and reducing their waist circumference.
There are additional studies which show similar results;
Study #1: looked at 8 male gymnasts who followed a ketogenic diet for 30 days, during which time they lost fat but increased muscle mass (34)
Study #2: looked at CrossFit training and showed no significant difference between keto and regular diet participants when it came to muscle mass and performance (35)
All this adds up to mean, if you hit your calorie and protein goal then you can maintain or even build muscle when following a ketogenic diet.
Of course, results may vary between individuals and it’s impossible to say what your individual outcome will be; maybe you thrive, or maybe you struggle.
At the end of the day you need to test it out and see what works for you and remember that your performance will take a hit for at least the first 2 weeks as you adjust to using ketones for fuel.
Keto Diet FAQ
Answers to the commonly asked keto diet questions;
Can I Drink Alcohol When Following A Ketogenic Diet?
Yep, you can if the carb content doesn’t knock you out of ketosis. This means you need to vigilant with both what you drink and how much you drink.
Good options are;
Low carb beers
Like with everything else you need to make sure you account for the alcohol in your daily calorie and macro allowance.
Always drink in moderation.
When Should I Not Do the Ketogenic Diet?
Whilst for most healthy people the keto is perfectly safe there are some situations when you should avoid it;
Type 1 diabetes
Impaired liver function
Gastric bypass surgery
You should always consult your doctor before switching diets or doing something different, particularly something like the keto diet.
How Do I Get Started with the Keto Diet?
If you know you’re in good health and want to try doing a ketogenic diet, then a good place to start would be following it for at least 30 full days.
This gives you a chance to get fully adjusted and get a real feel for the diet and how you function when following it.
You can then decide if it’s for you or not.
Do I Need to Count Calories When Doing Keto?
Not necessarily, although it will make life a lot easier.
In order to get into and then maintain a state of ketosis you need to eat 5% of your daily allowance as carbs. If you’re not counting calories, then you’ll struggle to accurately know what this is.
This means you could be constantly knocking yourself out of ketosis or you may never reach it in the first place.
At the very least you should count your calories for the first couple of months whilst you get to grips with the diet and the carb content of certain foods.
Can I Do Intermittent Fasting When Following A Ketogenic Diet?
Yep you can. In fact, some people swear by its effectiveness when the 2 protocols are done together.
Following something like the 16:8 intermittent fasting structure is a good idea if you’re going to try this.
Can I Do A Ketogenic Diet if I’m Vegetarian?
You sure can.
You will just need to be careful that you’re getting enough protein in your diet. However, if you can do this then there is no reason you cannot follow a ketogenic diet.
The ketogenic diet is a low carb, high fat diet. It works by forcing your body to adapt to using ketones for fuel in the absence of carbohydrate.
Whilst it has been shown not to be significantly different for fat loss purposes compared to moderate or high carb diets it may offer numerous other health benefits.
Current research shows that it is possible to lose fat, maintain muscle and build muscle when using the ketogenic diet provided protein intake is sufficient, training is well structured and overall calories support the goal.
At the end of the day the ketogenic is another way to create and maintain a calorie deficit, that may or may not be suitable depending on your lifestyle and dietary preferences.