If you’re looking for a major nutritional boost to your focus and energy levels, you should try out a ketogenic diet. This diet has gained popularity in the recent years as a very efficient diet for fat loss. Unlike many other diets, this one also has many other benefits from being neuroprotective to helping with Alzheimer’s and Parkinson’s.
Unfortunately, it’s also very inconvenient diet, because of its drastically different macro distribution from what you probably normally eat, but you don’t have to be in ketosis every day of the year. You can cycle this diet to meet your custom needs.
First, I’ll briefly tell what the ketogenic diet is, and the research behind it in terms of cognitive enhancement and focus.
At the end, I’m going to reveal my own results of the diet. Note that as the sample size is one (me), and the tests that I made are not randomized, controlled, or done in a clinical setting, you can’t take my results as an evidence for the diet. The results are purely anecdotal, and I provide them only for your curiosity and encouragement.
If you’ve read my post: building a strong framework for your focus, this would certainly be on the right side of your nutritional scale, since, this is not a typical diet, and falls more on the optimization side.
So if you think your nutrition has seen it’s better days, fix your nutrition to a healthy baseline first.
- 1 What is the ketogenic diet?
- 2 How does it work?
- 3 Why ketones instead of glucose?
- 4 Convinced? Then, what should you eat?
- 5 Isn’t saturated fat dangerous?
- 6 What about vitamins and other nutrients?
- 7 Any side effects?
- 8 Tests before, during, and after the diet
- 9 My results
- 10 After the diet
- 11 Conclusion
What is the ketogenic diet?
A ketogenic diet is a diet, in which you restrict your carbs to the very minimum, which often means 20g or below. Your primary macronutrient is fat, protein being the second. There isn’t a clear-cut macro distribution for the ketogenic diet, since the classical ketogenic diet used for treating epilepsy has very strict limits for macros, and doesn’t contain very much protein.
You are, however, able to enter ketosis just fine with so-called modified Atkins diet, which is a little more forgiving for protein intake.
A ketogenic diet has been in clinical use for over 90 years, primarily for the treatment of drug-resistant epilepsy. When nothing else works, the ketogenic diet can alleviate or remove the epileptic symptoms.
When your ketone bodies are above 0.5 mmoL/L, you are in ketosis.
Sometimes people mistake ketosis as being diabetic ketoacidosis. This life-threatening condition is completely different, and in diabetic ketoacidosis, your ketone body levels are above 12 mmoL/L.
How does it work?
When you limit your carbs below 20 – 50g per day, your body will start to deplete it’s glycogen from the liver since it can’t get glucose from your diet. This will take around 2-3 days depending on your physical activity.
Technically, since your brain uses around 100g of glucose per day, anything lower than this will induce ketosis to provide additional fuel to the brain, however, to achieve the depth of ketosis we require — we need to limit our carb intake to an absolute maximum of 50g, lower if possible.
After you’ve depleted your glycogen, your liver starts a process called ketogenesis, to produce ketone bodies from free fatty acids as a fuel for your cells. Some cells still use glucose as their energy, but since ketogenesis also produces some glucose, the cells which need it get their requirements that way.
First, ketogenesis produces a ketone body called acetoacetate, which then is used to make two other ketone bodies called Acetone and beta-hydroxybutyrate (BHB).
These ketone bodies are then readily absorbed by the mitochondria of your cells, and since the ketone bodies are able to cross the blood-brain barrier, your brain cells get the juice too — which of course is the basis of this whole article.
After around three days of following this diet, 25% of your brain cells get their energy from ketone bodies.
After the adaptation period (around three weeks) this goes up to 75%.
Why ketones instead of glucose?
How can a diet with no carbs affect your mental performance positively, doesn’t our brain cells run on glucose?
Yes, our brains run on glucose when it is present. However, when you limit your carbs to the very minimum, your body cannot generate enough glucose for the entire energy requirement of your brain, which is around 100 grams of glucose per day.
On top of that, unlike many other tissues in the body, your brain cannot utilize free fatty acids for fuel, which has lead to a common misconception that your brain can only run on glucose.
However, this is not the case at all since our brains can happily run on ketone bodies which are converted from free fatty acids. So our brains can run on fat, albeit indirectly.
To demonstrate the difference between glucose metabolism and ketone metabolism in cell respiration, first, let’s compare how one glucose molecule and one BHB molecule gets converted into ATP, which is the fuel that our cells use.
Since I am a detail oriented nut, I made this unquestionably beautiful drawing of a cell:
With glucose, first, it gets broken down into pyruvic acid through nine different stages. This whole process occurs inside cell’s cytoplasm, and it’s called glycolysis.
After these steps, the pyruvic acid is able to enter the cell’s mitochondrion and inside mitochondrion gets through two additional transformations to get converted into Acetyl-COA, which is a molecule that can enter the Krebs cycle to continue the process of being converted into ATP.
So all and all, glucose needs eleven transformations to end up as Acetyl-COA.
Now, let’s look at our competitor, BHB. Will it fare any better?
BHB enters mitochondrion as it is, so it doesn’t need any steps inside cell’s cytoplasm. In mitochondrion, it gets transformed into acetoacetate (which is one of the three ketone bodies, so in fact, acetoacetate itself doesn’t even need this step.) and further into acetoacetyl-COA, which is then transformed into two acetyl-COA molecules.
So in summary, glucose takes 11 steps and you get one Acetyl-COA molecule, and BHB takes three steps and you get two Acetyl-COA molecules.
Not a bad trade, should we say?
After this stage, Acetyl-COA molecules enter via the Krebs cycle to the electron transport chain to provide ATP for our hungry cells.
The net ATP gain of these two in comparison are theoretically:
- Glucose: 36- 38 ATP
- Beta-hydroxybutyrate: 48 ATP
The reason why BHB is not double compared to glucose is that you gain few ATP’s with glycolysis. All and all, if measured only by pure ATP net gain, we already have a winner.
So what about other factors than just ATP difference?
Ketone metabolism also seems to increase glutamate — major excitatory neurotransmitter — synthesis in the brain. Paradoxically, the excess glutamate gets converted into GABA which is the major inhibitory neurotransmitter in the brain.
GABA inhibits nerve transmission in the brain, calming your brain, so that’s probably why some people get a calming feeling during this diet. Some people — including me — even get an opioid like high feeling.
Additionally, a ketogenic diet can offer an increased neuroprotection in wide area of neurodegenerative diseases and traumas.
Convinced? Then, what should you eat?
Unlike a typical low-carb diet, ketogenic diet really minimizes your carbs, and you have to limit them to around 20g per day. This means cutting down all obvious carbs like bread and pasta, but it can also mean that you have to cut down the milk in your coffee. Either drink black or find a low carb substitute like Almond milk.
When you cut down your carbs this low, you emerge into a ketogenic state. In short, this means that some of the cells in your body, and neurons in your brain, start to use ketones as their energy source instead of glucose.
The classical ketogenic diet used for seizure control is pretty harsh in terms of macronutrients. Almost all of the energy intake comes from fats, so the macronutrient ratio is around 90% fat / 4% carbs and the rest goes to protein.
What I suggest is that you follow the modified Atkins diet which has a macro distribution of:
- Carbohydrates: 10 – 25g
- Protein: 1g – 1.5g per bodyweight in kg
- Fat: all the rest
With these macros, you should be able to enter ketosis just fine, and the aforementioned amount of protein will preserve your muscles much better than with the classical ketogenic diet.
What is important is that you keep your protein intake maximum 1.5 g/kg, as protein can be insulinogenic, meaning that excess protein can kick you out of ketosis.
Isn’t saturated fat dangerous?
Most people do eat quite a bit of saturated fat on this diet and have no adverse effects. If you are concerned about your saturated fat intake, it’s good to remember that there is no clear evidence of saturated fat — in itself — increasing your cardiovascular risk.
This does not mean that saturated fat couldn’t play a role in CVD if you combine it with high amounts of carbs.
On the other hand, there are people who get lethargic after eating saturated fat, so again, this is something that you have to experiment yourself. I don’t have any negative effects from saturated fat, and I drink quite a bit of bulletproof coffees because they are tasty and provide and easy way to get some fat to my system.
What about vitamins and other nutrients?
The most important thing you have to be concerned about is your electrolytes. In ketosis, your kidneys start to excrete electrolytes from your body at an increased rate, which means that you have to supplement these. You can find various electrolyte supplements on the market, but simply unrefined sea salt will do the trick.
Probiotics and prebiotics
The gut microbiota has been known to have a major effect on your overall health. Since your microbiota lives from the food you eat, you can be sure that there is bound to be major changes when you change your macronutrient distribution upside down!
For keeping your gut bacteria healthy and living, add some fermented foods into your diet, like cheese. You can also supplement probiotics but pick your brands carefully because some of the products out there have dead colonies of bacteria in them. What I recommend are Dr. Ohhira’s probiotics. They are a little bit pricey, but you can be sure that you’re getting the good stuff.
Also, your probiotics need food, so you consider prebiotics. Potato starch supplement is prebiotic which many people use.
MCT oil acts as an exogenous ketone producing agent since it contains medium chain triglycerides which convert directly into ketone bodies.
You can add MCT oil to every meal if your gut can handle it. If you eat lean protein like chicken, it can pretty easily kick you out of ketosis, since it doesn’t contain any fat. You can add MCT oil, or olive oil to your vegetables and meat, to make the meal more ketogenic.
MCT oil which contains caprylic acid (C8) and capric acid (C10), (but not lauric acid (C12)) is always the best option. If you want pure C8 oil, you can buy brain octane which is used if you make the original bulletproof coffee by Dave Asprey.
I use MCT oil found from my local grocery shop, and it contains both C8 and C10.
Any side effects?
While ketogenic diet is used by many without any adverse side effects, that doesn’t mean there could not be any. Some people report the following:
Many people report a higher LDL “bad” cholesterol after starting the diet. However, it should be noted that a higher LDL number in itself is not an indication of a cardiovascular risk, and should not be viewed as bad cholesterol at all.
In fact, there are two types of LDL cholesterol profiles, generally named Type A and type B. Type A LDL cholesterol profile tells you that thought you might have a high total LDL cholesterol mass, the way your LDL cholesterol is structured is that there are large amounts of LDL cholesterol in one LDL particle, making your LDL molecules big and fluffy.
On the other hand, if you have type B LDL profile, you can have the same amount of total cholesterol mass than in type A, but because you have a high number of triglycerides, they take up space from the LDL particles, leaving less space available for your cholesterol mass, resulting in more particles to carry the same amount of cholesterol.
The aforementioned arrangement is a stronger predictor of cardiovascular disease than type A. In fact, a high LDL and low triglyceride concentration may even be beneficial, because when this is the case, you usually have a high amount of HDL “good” cholesterol too.
Usually, when you start the diet, your triglycerides will go down after the adaptation phase, telling you that your LDL particle number is, not in fact, any higher than before.
If you want to know more about cholesterol, I recommend MD Peter Attia’s amazingly detailed series of posts called: the straight dope on cholesterol.
This is probably the most common side effect. Ketogenic flu can manifest as flu-like symptoms, but it can also mean you have brain fog, you are lethargic, unmotivated, and irritated.
This is the point where many people give up the diet because they think that it’s not suitable for them.
Just hang in there; the brain fog is present because your brain is switching its primary fuel source from glucose to ketones, and if you are not fat-adapted, this can take some time.
Dom D’agostino recommends that you help your brain ketone metabolism by taking some exogenous ketones. You can use straight up ketone esters, like KetoCaNa, or add some MCT oil to your diet, which acts as a ketone producing agent.
Also, you have to take care of your electrolyte balance. If you get past the initial ketogenic flu, but experience flu-like symptoms during the diet, from my experience, it’s almost always because of electrolyte imbalance.
If you have constipation, the problem is that you’re not getting enough water, and/or fiber. So drink some more water, and remember to add salt to the water.
To get fiber, add some non-starchy vegetables to your diet. These are:
- Spinach or any type of leafy green vegetable
You’ve started the diet and now you’re breath smells like acetone?
What the hell is this?
This is, in fact, a clear sign that your body is using ketones as energy. The excess acetone gets out from your body through breath.
Good news is that usually it goes away after one or two weeks from starting the diet.
Some people have sleep problems during the initial induction phase, but after they’ve gotten used to the diet, usually, they report better sleep quality, and less amount of sleep to feel refreshed.
Reduced physical energy
If you are working out physically, what you most likely get in the early stages of a ketogenic diet is reduced physical energy. Your body is not used to using fat as it’s energy source, so it is fighting against this change, and demanding more glucose.
If go to the gym regularly, you may find that you need to reduce your weights. Don’t worry, this doesn’t necessarily mean that you’ve lost any muscle, you’ve just depleted your muscle glycogen. That will also lead to your muscles showing off smaller because much of the puffiness of your muscles comes from the water stored inside.
Usually, once you adapt to the diet, you get your strength back and you can even increase it. But if you want to build more muscle, being on a strict ketogenic diet may not be the best option for you. Building up muscle with carbs is a lot easier. However, many bodybuilders cycle on to ketogenic diet before a bodybuilding competition, because it’s probably the most efficient way to lose fat.
If you’ve been on a ketogenic diet for a while, and still feel a lack of energy, you may want to drink more water with salt, and just a little bit of carbs, or switch on to low carb or moderate carb diet.
Cramps are your body telling you that you need more electrolytes. Add sodium, magnesium, and potassium to your diet.
Tests before, during, and after the diet
Even after the adaptation period, some people have problems with fat metabolism. This is why you have to go and take at least your lipids profile (LDL cholesterol, HDL cholesterol, and triglycerides) before, during, and after the diet. Also, I would suggest that you also measure your sensitive C-reactive protein (S-CRP), because it’s a clear indication of an inflammation.
In fact, I suggest that you do these measures a few times a year, maybe once in a quarter, because your lipids and especially your S-CRP can be an indication of a problem which doesn’t yet manifest physically.
How to read your lipid profile
If your LDL and triglycerides skyrocket and stay elevated for a long time (several months), it may be an indication of a problem with fat metabolism, and this diet may not be suitable for you.
Usually, your HDL will go up quite a bit, LDL will go up also, but your CRP and triglycerides should be stable. Note, that anything is possible if you measure your lipids during your adaptation period, so initially, all of your lipids can go up, but at least your triglycerides should come back down once you’ve adapted to the diet. As an anecdotal reference, you can take a look at my blood test results.
Blood glucose and ketone tests
Blood glucose and ketone measurements you take from blood with a glucometer is an accurate method of keeping track of your ketosis. A glucometer with ketone strips will measure your BHB level in your blood.
You can use urine tests if you want, but these are by no means accurate at telling your level of ketosis. They measure acetone excreted from your urine, which doesn’t necessarily tell you anything about your BHB level. You can use urine tests at first to find out whether you are in ketosis or not, because the ketone strips are pretty pricey.
I used the Abbott labs Precision Neo meter (Europe version). Note that the US version of this same meter looks exactly the same but does not measure ketones, so if you want to be safe, you can get the Precision Xtra meter which does measure ketones.
Aside from the meter itself, you have to buy a supply of lancets, glucose strips, and ketone strips. The lancets and glucose strips don’t cost much, but again, the ketone strips are pretty hefty on their price.
For this experiment, I went for the modified Atkins diet, which I introduced to you in the beginning. It is much more forgiving of small amounts of carbs. You should get around 20-25% protein intake to preserve your muscles.
For me, this meant around 2000 kcal per day. I tweaked the caloric intake so that I would slightly lose fat at the same time, but not dramatically, almost close to maintenance.
Macronutrient distribution for me was:
- Carbs: 5% 25g
- Protein: 25% 125g
- Fat: 70% 156g
I stabilized myself into a healthy baseline before starting the ketogenic diet. This meant that I dropped out most if not all processed sugars, and otherwise ate pretty healthy food. I don’t know if this had any effect, but since dropping out just sugar from your diet can anecdotally give you cognitive benefits, I had to make sure that I didn’t get skewed results from the absence of processed sugars.
I was already consuming a good amount of healthy fats, and I was getting around 3g of omega 3’s per day, which is well above the minimum requirement. If I would’ve had a mild omega-3 deficiency before the diet, some cognitive benefits could have been explained by getting the omega-3 to adequate levels.
Since this was done as an experiment, albeit a few exceptions, I ate:
Morning smoothie, which had
- 50g blueberries
- 1/3 avocado
- 30g walnuts or macadamia nuts
- Some almond milk
After this, I drank two bulletproof coffees which had 40g of butter and MCT oil.
For lunch, I had an omelet or scrambled eggs with five eggs.
For dinner, I had 200g of ground beef with vegetables.
In the afternoon I ate 170g of bacon with vegetables.
I was able to eat like this during the whole 30-day experiment, which meant that I had little or no caloric or macro nutritional variation. However, if I needed to be in ketosis all year, I would have to come up with some variation to the diet.
Blood tests before and after
If you look at my blood test, initially it seems that all of the measurements except S-GT got somewhat worse. It seems that one month was not enough for me to fully adapt to this diet in terms of fat metabolism.
|Glutamyltransferase (S-GT)||35 (U/L)||21 (U/L)|
|Sensitive C-reactive Protein (S-CRP)||0.12 (mg/L)||0.44 (mg/L)|
|Fasting Glucose (fP-Gluc)||5.20 (mmol/L)||4.10 (mmol/L)|
|Total Cholesterol||4.50 (mmol/L)||7.40 (mmol/L)|
|High density lipoprotein (HDL)||1.50 (mmol/L)||1.40 (mmol/L)|
|Low density lipoprotein (LDL)||2.50 (mmol/L)||5.30 (mmol/L)|
|Triglycerides||1.06 (mmol/L)||1.47 (mmol/L)|
After the second blood test, I resumed a diet where I ate pretty much keto-based on weekdays and ate freely on weekends. I still consumed the at least four bulletproof coffees per day, which meant that my saturated fat intake was up the roof. When I took my lipids two months after eating like this, I had the following:
|High density lipoprotein (HDL)||2.0 (mmol/L)|
|Low density lipoprotein (HDL)||5.0 (mmol/L)|
The lipids suggest that I had become efficient at fat metabolism since my HDL was now 2.0, and my triglycerides went down to 0.60.
From the picture below, you can see my ketone levels taken each morning fasted. I’ve marked the days when the cognitive effects of ketosis were the highest (green). These were the days from 6 to 10. I experienced the highest amount of focus, and also when I experienced a “keto high”.
I also started to experience a constant headache and a mild brain fog when my BHB levels were above 2.0. I couldn’t remove this headache with electrolyte or MCT supplementation. I was able to get rid of it only when I upped my carb intake which lowered my ketone levels down to 1.6.
During the latter third of the diet my stomach rose up in a mutiny, and I had diarrhea, which was undoubtedly caused by the changes in my gut bacteria. The stock of my usual probiotics was empty (Dr. Ohhirras) so I took some general probiotics from my local pharmacy which did nothing. Only when I ate some probiotic yogurt, my diarrhea went away but it came back soon enough.
As I was doing extremely simplified strength routine before I started the diet, so I continued doing just that.
I managed to keep my strength levels the same, but during the second week, they started to dip. Most notably my bench press decreased, I don’t know why this is the case, but all I know that from all of my previous diets, by bench press always takes the bigger toll, and getting it up takes also the longest time.
I was able to recover some of my lost strength levels during the third and last week and managed to increase my output on deadlift also. All and all, I was feeling energetic in the gym, so there was no notable energy dip, I just didn’t have the punch.
My focus went notably up. It’s of course only my anecdotal feeling, but I did felt notably easier to focus deeply and maintain it for a longer period of time. Luckily for us, this diet is perfect for focus boosting effects.
The second night when I was in ketosis, I couldn’t get barely any sleep. Usually, when I feel insomniac, I am tired, but my mind is overanalysing things, so I can’t get myself to sleep. This feeling wasn’t like that, I was more like feeling too energetic to go to sleep.
After the induction period, my sleep was better than ever. Normally I wake up a few times during the night but when I was in ketosis, I got nonstop hours of sleep every night. Some people also say that they require less sleep when they are in ketosis, but I didn’t notice this.
No notable benefits to memory.
The notorious afternoon dip was mostly gone. During the days I was at the gym, I had a bit of a tiredness in the afternoon, but I wasn’t too tired to actually lose my concentration. With my normal diet, I constantly get this “out of resources” feeling in the afternoon, and the only way to reset it is to have a nap — which isn’t necessarily a bad thing.
However, during my keto days — and especially the days when I didn’t exercise — my mental resources stayed about the same during the whole day. That isn’t to say that you shouldn’t get a nap anyways, it probably has benefits.
Other than the notably increased focus, I also had an opioid like high effect. This effect was most notable when I was in the green zone (see the graph above). The effect in the beginning was so strong, that I could’ve easily believed that I was high on something. When I did research about this, there were others who had the same effect than I did. Possible explanations for this is the increased GABA in your brain.
After the diet
I started to appreciate the focus enhancing benefits of this diet after I returned to my regular diet, which isn’t necessarily a high carb diet but contains around 100 – 150g of carbs per day. The day after I returned to my normal diet, I felt actually pretty good, but the following night I couldn’t get any sleep, so I guess switching your main source of energy of your brain is going to give you some interruptions.
Now that I had a reference point from the ketogenic diet, I compared how I felt after introducing carbs again, and sure enough, I got a mild chronic brain fog when I ate so-called “normal food”.
This was unnoticeable before because I didn’t know any better.
I think the ketogenic diet is one if not the most optimal diets if you want a cognitive boost, the downside being that it’s so unconventional. You probably don’t want to remain in ketosis all year long, although that is completely doable.
For myself, I intend to cycle this diet couple of times per year, not only because of the focus enhancing effects but also because of other possible health benefits.
Have you tried the ketogenic diet and if you have, what were the results?