The ketogenic diet is a way of eating that is very low in dietary carbohydrate.
Perhaps you are wondering about trying the diet, yet there are some burning queries in your mind.
Maybe you're wondering about the health benefits?
Or maybe you have a few concerns over some potential side effects?
This guide will take a look at the most common questions concerning keto diets, and then provide the answers you need.
1. What is the Ketogenic Diet?
Put simply, the ketogenic diet is an eating plan that emphasizes high-fat, moderate-protein, and low-carb.
As you can see in the above food pyramid, the diet is based around animal foods, low-sugar fruit, and vegetables.
Keto restricts carbohydrates to a level that results in the body switching to burning fat for fuel.
On the positive side, the diet has a wealth of health benefits, but there are also some potential side effects to be aware of.
We'll explore both the pros and cons later in this guide.
Key Point: Keto diets are high in fat and low in carbs. Additionally, they usually have a moderate protein intake.
2. How Does the Ketogenic Diet Work?
When we are eating large amounts of carbohydrate, our body stores them as glycogen.
Glycogen is basically a form of stored glucose which we can find in our liver and muscles. In the presence of adequate glucose, the body will burn this carbohydrate as its primary source of energy.
However, when we restrict carbohydrate, after a few days our body becomes deprived of glycogen.
As a result, our body requires a new energy source - fat.
In order to burn fat for energy, our body must first convert the fatty acids in our body to compounds known as ketone bodies.
Otherwise known as ketones, these molecules are produced by the liver in times of carbohydrate restriction.
The whole process of burning fat for fuel is referred to by the name 'ketosis'.
Key Point: Restricting carbohydrate consumption causes the body to burn fat as an alternate energy source.
3. What is Ketosis?
As previously mentioned, ketosis simply refers to the state during which the body burns fat for fuel.
In other words, when the body is producing ketone bodies, we are "in ketosis."
The three ketone bodies are shown above; acetone, acetoacetate, and 2-hydroxybutyric acid.
Overall, the general population spends very little time in this state due to the prevalence of high-carb diets. However, when carbohydrate is very low---either through lack of food or a low carb/keto diet---the body can freely enter ketosis.
While this may sound like a radical change for the body, it is a normal metabolic state. In fact, it is likely that humans spent significant amounts of time in nutritional ketosis throughout our history, especially during cold winters and the ice age.
Of course, just because we used to do something doesn't necessarily make it right or healthy. But being in ketosis does confer some health benefits, and it is why the diet enjoys popularity.
In addition to to the popularity of keto diets for general health, ketosis sometimes plays a role in the treatment of medical conditions such as epilepsy.
Key Point: Ketosis occurs when the body starts producing ketones for fuel. To put it another way, the body is running on fat for fuel rather than carbohydrate.
4. Are There Any Signs Or Symptoms of Ketosis?
Yes, there are some common signs that the body is in ketosis.
These usually show up within the first 48 hours or so.
While some symptoms will probably be welcome, unfortunately they are not all positive.
For example, these symptoms may include the following;
All 'symptoms' related to ketosis are generally short-term only, and they soon subside (except for the improved satiety).
We will look at these more when we examine the potential side effects of starting keto.
Key Point: Quickly losing water weight, a metallic taste in the mouth, and appetite suppression are all signs the body is entering ketosis.
5. How Can I Tell If I'm in Ketosis?
It isn't necessary, but some people like to know if they are in ketosis or not.
If you wish to track this, then you can use urinalysis to have a better idea.
This involves using something called a 'ketone strip'.
After taking a urine sample, holding the strip in the sample will cause the ketone strip to change color.
The color it changes to will represent the amount of ketones in the urine.
This isn't a 100% foolproof
method to measure your level of ketosis, but it generally works well.
See here for some more information: how to use ketone strips.
Key Point: Ketone strips are a cheap and useful way to check if the body is producing ketones.
6. What Happens To the Body in Ketosis?
Well, there are many things that happen when your body switches away from burning carbohydrate to use fat for fuel.
It's important to be aware of this, because you are essentially changing the way in which your whole metabolism works.
Here are the main things to note;
However, remember that it may take a bit of time for the body to get used to these changes.
Key Point: During ketosis, the body starts to efficiently burn fat for fuel rather than carbohydrate. As a result, blood-glucose levels typically drop.
7. Is Ketosis Bad For You?
No, ketosis is a normal metabolic state that the body can freely enter (and leave) when carbohydrate/food intake is low.
Generally, the only issue is the short-term side effects while the body adapts to this new state.
That said, there can be some complications in people with diabetes (see the next question).
Other than this, there is nothing specifically bad about ketosis.
We are all different, so perhaps being in ketosis won't be the right fit for every individual. But there is nothing inherently dangerous about it.
Key Point: For otherwise healthy individuals, ketosis is a normal metabolic state in which fat provides our body's fuel source.
8. Does Keto Cause Ketoacidosis?
First things first; ketoacidosis is an incredibly dangerous medical emergency.
The condition is otherwise known as diabetic ketoacidosis (DKA), and it usually occurs as a result of the poor management of diabetes (particularly type 1).
Symptoms may include abdominal pain, dehydration, and shortness of breath. Ultimately, ketoacidosis can be fatal.
Should anyone experience these symptoms, they should seek medical advice immediately.
Okay, but does Keto Cause It?
Since ketoacidosis results from a build-up of ketones in the blood, people often assume ketogenic diets play a role.
The assumption is made that;
"If ketosis increases blood ketones, and if excessive levels of ketones lead to ketoacidosis, then ketosis must cause ketoacidosis too".
However, ketoacidosis and ketosis are completely different.
Specifically, in metabolically healthy individuals, insulin stops our body from overproducing ketone bodies.
For diabetics, it is essential to discuss and carefully plan any change in diet.
There is a lot of great information online, but don't solely rely on generic information from a website - get personalized guidance from your medical practitioner.
Key Point: It's important for diabetics to be aware of ketoacidosis. However, this shouldn't be a concern for healthy individuals.
9. Is a Ketogenic Diet Safe?
Millions of people around the world are safely doing ketogenic diets.
Additionally, systematic reviews show that very low carb diets result in better long-term weight loss than low-fat diets.
Furthermore, they tend to reduce cardiovascular risk factors more than low-fat diets do.
The single-most important thing is to research the diet before starting it.
Make sure you know how it works, the potential short-term side effects, and the overall pros and cons.
Remember: there's no one-size-fits-all diet that's right for everyone.
Key Point: High-level evidence in the form of systematic reviews show that ketogenic diets are safe up to the 1-year mark. There are currently no longer-term studies, but there's no reason to believe they can't be healthy in the long-term.
10. Is a Keto Diet the Same As Zero Carb?
No, they share some elements of carbohydrate-restriction, but they are very different overall.
Firstly, ketogenic diets include a variety of animal and plant-based foods.
On the other hand, zero carb diets completely eliminate all sources of carbohydrate and specifically focus on animal proteins.
There is a growing amount of data on the benefits of keto-style diets, but as yet there is very little on zero-carb.
As always with nutrition, we should be open-minded and this does not mean such diets can't be healthy.
At this time, ketogenic diets have a much stronger evidence base.
Key Point: Ketogenic diets usually include a variety of plant-based foods, while zero carbohydrate diets do not.
11. Is Keto Good For Losing Weight?
First of all, individuals starting keto usually experience significant weight loss in the first week.
This is simply because the body stores approximately 3 grams of water per gram of glycogen. Due to dietary carbohydrate-restriction, glycogen stores drop, and we also lose this water weight.
Not only does keto result in short-term weight loss, but also longer term weight loss too. A wealth of studies show that very low carb ketogenic diets beat low-fat diets for weight loss at the 3, 6, and 12-month mark.
One great point about ketogenic diets is that they tend to increase satiety, thereby naturally reducing food intake.
Key Point: Ketogenic diets tend to increase satiety and reduce food intake. They consistently result in a better weight loss than low-fat diets at the 3, 6 and 12-month mark.
12. How Much Weight Can I Lose?
Overall, the key to sustainably losing weight is compliance to the diet.
It's not a crash diet for short-term weight loss, it's more a way of committing to a longer-term healthy lifestyle.
Make sure it's the right choice for you and that you feel you can stick with the diet, and, providing you formulate the diet well and eat the right foods, you should see weight loss.
How Many Kilograms Can I Lose?
This is difficult to answer; everyone is different and has a different weight and amount to lose.
In fact, if you see any diet claiming the exact same level of weight loss for everyone then it's probably worth ignoring.
For example, some people suffering from obesity have lost tens of kilograms, while other people have less to lose.
Hormones, weight, diet, lifestyle, sleep, and an assortment of other factors play a role.
Key Point: Don't expect (or stress over) an exact level of weight loss. Providing you eat a sensibly implemented diet, you should see consistent weight loss results.
13. What Foods Can I Eat?
Ketogenic diets should be based around low carb foods, with a moderate to high intake of fats and protein.
As a result, the diet usually revolves around animal foods and lower carb plant food.
These foods usually come from the following groups;
Key Point: Ketogenic diets are based around the combination of animal foods and low-carb plant foods.
14. What Foods Should I Avoid or Restrict?
There are two types of food that keto dieters typically restrict; foods which are moderate to high in carbohydrate, and processed fats.
While highly processed vegetable oils are technically 'ketogenic', they are not so good for our body.
A properly-implemented keto diet should restrict the following foods;
Key Point: Ketogenic diets emphasize restricting foods that are higher in dietary carbs. As a result, things like bread, mango, and spaghetti are off the table.
15. How Much Carbs, Fat, and Protein Should I Eat?
Every individual is different, and this very much depends on what you are eating, how active you are, and personal biology.
That said, if you are trying to get into a state of ketosis, then restricting carbohydrates to an upper cap of 50g net carbs is a good idea.
Typically, ketogenic diets are high in fat and moderate in protein.
Despite this, many people do well on a higher protein intake and manage to stay in ketosis too.
Go with what feels right for you.
Key Point: Aiming for a maximum limit of 50g net carbs is about right. The rest of the diet can then be filled out with fat and protein.
16. What is a Net Carb?
Net carbs are simply the carbohydrate content of food minus the amount of fiber present.
For example, taking the potatoes on the right, per 100g they contain;
- 17g total carbohydrate
- 2.2 fiber
As a result, they contain of 14.8g net carbs.
If you are wondering why we would calculate net carbs, it is because (insoluble) fiber does not get digested by the body (and raise blood sugars).
However, this rule isn't always perfect because our body can still absorb soluble fibers.
If you wish to be sure and don't want to attempt counting fiber intake, then you could just aim for 50g of total carbohydrate.
Key Point: A net carb is the amount of carbohydrate in a food minus the fiber content.
17. Are Carbohydrates Bad For Us?
Carbohydrates are a wide-ranging class of foods that contain everything from green vegetables and berries, to soda and pastries.
Are carbohydrates bad?
As a general rule, no - not in their unprocessed state.
For example, berries growing on a tree or onions pulled from the ground; they are in their natural whole-food matrix, and they contain numerous health-supportive nutrients.
On the other hand, most commercial breads are heavily refined, bleached, and stripped of their nutritional value. Additionally, products like soda and candy are full of sugar and result in blood-sugar spikes.
So, whether "carbs are bad" or not very much depends on the type of carbohydrate.
Why Restrict Carbs If They're Not "Bad"?
The ketogenic diet is just one dietary style.
When properly implemented and when it emphasizes healthy food choices, it can have some impressive health benefits.
However, it is not the only way of eating. If you feel very-low carb dieting is not right for you, then there are other options.
Key Point: Carbohydrates are not---on the whole---bad for you. However, low-carb dieting can have many beneficial effects on the body.
18. Can I Have a Cheat Day?
You can if you must.
However, if you are trying to be healthy, then it's not advisable.
For one thing, frequent yo-yo-ing from high carbohydrate to low carbohydrate is going to make it difficult to adapt to the keto diet.
Additionally, it's probably confusing (and not healthy) for the body.
If someone wishes to eat more carbohydrate on a regular basis, then a ketogenic diet isn't a good match.
Something like a moderately low-carb or paleo diet (<150g carbohydrate) may be a better choice.
Key Point: Cheat meals/days are not the best idea and don't fit well with a keto diet. If they are important to you, then considering a less-restrictive diet is a good idea.
19. Can I Use Sweeteners?
Sweeteners are an option, and they are certainly healthier than sugar.
However, studies on artificial sweeteners are not conclusive and systematic reviews suggest they may have an adverse effect on the gut microbiota.
So-called natural sweeteners such as erythritol, monk fruit, and stevia appear to have a healthier profile.
But it is a stretch to say that any sweetener is "healthy".
If you wish to use sweeteners, it's unlikely to be a problem, but in my personal view - it shouldn't be an every day thing.
Key Point: Sweeteners are a big improvement on sugar consumption, but we can't really call them healthy. They are compatible with keto if you want to use them.
20. Should I Take Supplements on a Keto Diet?
Again, this is up to you.
Personally speaking, I believe it's better to get nutrients from food rather than a synthetic vitamin/mineral tablet.
A diet rich in a variety of nutrient-dense food is unlikely to necessitate additional vitamin or mineral supplementation.
That said, many people find it difficult to get the daily amount of certain minerals, so supplementing is an option.
On this note, taking magnesium and potassium supplements can be a big help to people first starting a ketogenic diet.
This is because these electrolyte minerals can help reduce the side effects during the 'keto flu'.
Key Point: Supplements are not necessary, but they are an option - it's a personal choice. However, they shouldn't be needed if the diet is focused on healthy whole foods.
21. Does Keto Have Any Side Effects?
Yes, keto can have some side effects - specifically when first switching to the diet.
Some of these are mentioned in question 4, but they potentially include;
Not everybody suffers from these effects, but for those that do it's certainly not a nice experience.
Fortunately, they are only short-term.
They can be explained as the difficulties the body has in adjusting from using carbs to fats for fuel.
For more information, see here: the keto flu and how to beat it.
Key Point: Starting a keto diet may involve some short-term side effects. It's important to know what these effects are and how to manage them.
22. Why Do I Feel Tired On Keto?
Fatigue and feeling tired is one of the most common side effects when starting a ketogenic diet.
For example, for many people switching to keto, their body has been running on an ample supply of glucose for their entire life. Suddenly restricting this glucose supply is a major change for the body, and in the initial stages our body looks for this glucose for energy.
While these low energy levels are not enjoyable, they are perfectly understandable in this context. When our body realizes this glucose supply is not-present, it up-regulates fat-burning enzymes and starts producing more ketones.
Until the body becomes efficient at using fat for energy, these feelings of tiredness linger. For the majority of people, these side effects last anywhere from 2 or 3 days to a week.
Key Point: Feeling tired is a typical side effect when first starting keto. It occurs while the body adapts to burning fat for fuel.
23. What is Gluconeogenesis and How Does It Work?
Gluconeogenesis (GNG) is a metabolic process through which the body converts non-carbohydrates into glucose.
Although you may have heard people mistakenly say that "carbohydrate is essential," this isn't strictly true.
It is actually glucose that is essential, and a natural biological process allows us to make our own.
For example, our liver can turn amino acids (protein)---among other things---into glucose.
Since glucose is a necessary fuel for our body---particularly our brain---gluconeogenesis ensures we always have enough available.
The process happens naturally when we haven't eaten for a while; it occurs during sleep; and gluconeogenesis fuels glucose needs in the absence of carbohydrate.
Key Point: Gluconeogenesis refers to the process through which the liver converts proteins into glucose.
24. How Does Keto Benefit Mitochondria Function?
Mitochondria exist within every cell of our body and they are essential to our overall health.
Among other benefits, they play a protective role in our cells to protect against disease.
There are multiple ways through which they do this, and they create balance in our through controlling functions such as apoptosis.
Interestingly, research is showing that ketone bodies and---by association---ketosis, may help to improve mitochondrial health and protect against dysfunction.
Key Point: Research shows that ketone bodies may help improve mitochondrial health and function.
25. I Heard That Keto Cures Cancer?
If you heard this precise claim, then the source needs to be more responsible.
First of all, there is some interesting ongoing research into ketogenic diets and cancer.
As part of this research, some work---particularly in regard to certain types of brain tumor---could be promising.
However, to say that "keto cures cancer" is not supported by any high-level science.
Could it possibly play a role as an adjunct therapy for some cancers?
Sure, but evidence-wise more research is needed, and blanket claims that it "cures cancer" are going too far.
Key Point: Can ketogenic diets play a potential role in treating cancer? Maybe, but more research is necessary. Stronger claims are hard to support at this time.
26. Can Keto Treat Epilepsy?
Yes, a wealth of research shows that ketogenic diets may play a positive role in the treatment of epilepsy.
A systematic review shows that a ketogenic diet is a "relatively safe dietary therapy" in children.
Also, various trials show that it holds benefit for adult sufferers of the condition when compliance remains high.
Important note; if you are considering this diet for any medical condition - talk to your medical team about it.
Key Point: Ketogenic diets are a common dietary therapy for epilepsy.
27. Is the Keto Diet Good For Type 2 Diabetes?
There are many different nutritional strategies that can improve or potentially reverse type 2 diabetes.
However, it appears that very low carb ketogenic diets are most effective than low-fat diets in reducing blood-glucose and insulin levels.
Several meta-analyses and systematic reviews show this.
In fact, a recent 2017 review of 10 randomized trials found that "the greater the carbohydrate restriction, the greater glucose lowering".
Key Point: There is strong evidence for ketogenic diets being an effective dietary intervention for type 2 diabetes.
28. Can I Drink Alcohol On Keto?
There is no reason why you can't drink alcohol on a ketogenic diet, providing it is a low-carb choice.
For instance, typical beers and sugar-sweetened beverages/cocktails are on the avoid list.
However, wine and spirits are generally very low in carbs and they are suitable for a keto diet. Regarding wine, it is better to choose dry varieties to minimize the carb content.
There are also low-carb beers available and these include Beck's Premier Light and Miller Lite. Generally speaking, the 'light' varieties of beer only contain a few grams of carbohydrate per bottle.
That being said, everyone should still exercise caution with alcohol. While a small to moderate amount might be healthy, excessive amounts of alcohol are very harmful to health.
It also goes without saying that individuals with any kind of addiction or dependence issues should completely avoid all alcohol.
29. Can I Drink Coffee on Keto?
Yes, there should be no problem with drinking coffee.
First, there are two myths that need putting to rest;
However, be aware that coffee---and caffeine in general---is one of those things that affects different people in different ways.
If you feel good after coffee, then you should be able to enjoy it while on a ketogenic diet.
On the other hand, some people find it causes dehydration/digestive/anxiety issues, and these people would be better restricting it.
There are anecdotal accounts that anxiety issues with caffeine (due to the release of cortisol) may be exacerbated while on keto.
Key Point: Providing you normally tolerate coffee well, there should be no issue consuming it on a keto diet.
30. What Kind of Drinks Can I Have on Keto?
There are many drinks that are suitable.
Similar to the guidance about alcohol, you can have any drinks providing that they are low in carbohydrate.
Some of these may include;
Since milk contains approximately 5g carbohydrate per 100 ml, it isn't really suitable.
That said, if you're having just a little bit with your tea or coffee it is probably OK.
Key Point: Common keto drink options include coffee, tea, and water.
31. Is Keto Suitable For Vegetarians or Vegans?
It is possible for vegetarians to follow a ketogenic diet.
With the exception of fish and meat, the rest of the dietary choices can remain the same.
However, it is not easy. Being a vegetarian puts a large reliance on dairy foods and eggs for protein.
Should a vegetarian wish to include other sources of protein---such as fermented soy and beans---then a standard low-carb diet might be a better choice.
It is also possible (but extremely difficult) for vegans to follow a keto plan.
In the first place, being limited to very low-carb options and avoiding animal foods makes it hard to get sufficient protein. Certainly, it is difficult to acquire all the amino acids your body needs from such a diet.
In this diet, you would need to primarily focus on soy protein, seeds, and nuts for protein.
It would also be highly advisable to track your nutrient intake to make sure you're free of vitamin/mineral deficiencies.
Personally, I wouldn't recommend a vegan ketogenic diet.
Key Point: It takes a bit more work, but vegetarians can successfully follow a keto diet. However, implementing a healthy and safe plan is very difficult for vegans.
32. What Does CKD and TKD Mean?
CKD stands for 'cyclical ketogenic diet', and TKD refers to a 'targeted ketogenic diet'.
Both of these are varieties of following a standard keto diet, but with some key differences.
Cyclical Ketogenic Diets
Followers of cyclical keto diets (CKD) consume a very low amount of carbohydrate, but they have intermittent periods of a moderate to high carb intake.
This could be once per week on the same day and it is otherwise known as a 'carb up'.
The reason for this is usually related to sports performance, as the bulk of high-level evidence---at this time---suggests that carbohydrate is important for high-intensity exercise.
As a result, cyclical ketogenic diets are most popular with bodybuilders and athletes.
However, this does not mean that we can't perform exercise well on standard keto diets. For one thing, early research suggests that sporting performance on keto depends on the degree of keto-adaptation.
Targeted Ketogenic Diets
The targeted ketogenic diet (TKD) is also a standard keto way of eating with the exception of eating carbohydrate at specific times.
In the case of TKD diets, this carb consumption happens around the time of your workout.
As a result, TKD followers tend to eat carbs before and after exercise on the days they workout.
Key Point: CKD and TKD diets follow the standard keto way of eating except for intermittent periods of carbohydrate consumption.
33. Should I Fast on Keto?
You can if you want.
Intermittent fasting has been shown to have a few health benefits---particularly for overweight people and those attempting to reverse type 2 diabetes.
These health benefits may include better weight management, and lower blood pressure and blood-glucose levels.
By its very nature, it understandably works well for fat loss---at least in the short-term.
However, although fasting may have benefit, it is not imperative.
Key Point: Fasting has some nice health benefits, but it is a personal choice rather than an essential one.
34. How Does Keto Compare to the Paleo Diet?
Sticking to the strict definition of a paleo diet, there are some key differences between keto and paleo;
Carbohydrates restricted to a maximum of 50g
There is no real cap on carbs, and paleo dieters often eat starchy vegetables
No restrictions on dairy
No dairy on paleo.
Low-sugar fruits only
All fruits are OK
No refined sugars/carbs
No refined sugars/carbs
No natural sugars
Coconut sugar and honey are OK
Overall, both diets offer benefits and drawbacks.
Providing followers emphasize whole, nutrient-dense foods, then there's no reason why either diet can't be healthy.
Everyone is a little different, and paleo may be the right fit for some, while keto will suit others better.
Key Point: Paleo and keto are actually vastly different in composition. Paleo has no carbohydrate limits, while keto does. They are both similar in the way they emphasize natural foods.
35. Is Keto Good For Athletes?
Many athletes are performing well on ketogenic diets.
However, at this time, the bulk of high-level evidence suggests that traditional carbohydrate-fueling is the better option for high-intensity sports performance.
That said, researchers believe that fully keto-adapted athletes (over several months) may be able to perform equivalent to that of carbohydrate-fueled athletes.
To substantiate this claim, further studies on athletic performance are necessary in longer-term keto-adapted athletes.
Read more here: the performance benefits of keto-adapted athletes.
Key Point: Keto is an option for athletes, but at present, the evidence-base suggests carbohydrate fueling is better for high-intensity sports performance.
36. Where Can I Find a Keto Macro Calculator?
Macro calculators are far from necessary, but they can be a handy aid for those who like to track what they are eating.
Perhaps the best example of these calculators is located here.
You can use this tool to plan the exact amount of carbohydrate, fat, and protein you should target.
Key Point: You can use this macro calculator to plan a ketogenic diet that's right for you.
37. What Can I Eat For Breakfast?
This is an extremely common question for those new to ketogenic diets.
Firstly, you have to get out of the mindset that breakfast is cereal and toast.
Cereal companies have done an amazing marketing job here because we all ate a traditional hot cooked breakfast in the mid-20th century.
In short, breakfast can be anything you want it to be.
Some popular options include;
As you can see, there is a range of different breakfast options.
For further examples and a guide that explains why keto breakfasts beats sugary cereal, just see here.
Key Point: A hot-cooked breakfast is much healthier than ultra-processed cereal.
38. Where Can I Find Some Keto Recipes?
There are thousands of different websites offering a variety of recipes, and they are just a Google search away.
To get you started, you can find a few recipes here.
39. Is Keto the Best Diet Out There?
The best diet for every individual is likely a little different.
The food we thrive on can depend on many things, including our hormones/existing health, taste preferences, cultural considerations, and beliefs.
In other words, there is no one-size-fits-all diet that is the right match for all people.
As a result, the ketogenic diet might be a great idea for some people, but not the right match for others.
It is an option, and when done the right way - a very good option.
Key Point: Keto diets have impressive benefits and many people enjoy them, but they're not the right fit for everyone.
40. Where Can I Find a Keto Diet Meal Plan?
If you'd like a 7-day keto meal plan, just enter your details below to get a PDF copy sent to you.