For quite some time now, I have been a defender of the ketogenic diet. Not a proponent, but a defender. The reason for this is simply because I am pro-evidence. There are many within the nutrition space who equate nutritional ketosis with diabetic ketoacidosis and as such, announce that the ketogenic diet is not safe for use by the general population. This occurs despite the fact that almost every paper related to the ketogenic diet states the physiological differences between nutritional ketosis and diabetic ketoacidosis in the introduction. To this point, while many claim to be evidence-based, they are hilariously mistaken.
If you are familiar with my content, you may know my series “Fallacies of an Undergraduate Nutrition Major,” or FUNM for short. In these articles, I debunk erroneous claims made by my peers and professors during my time at University. One of the first articles I wrote was about the ketogenic diet being depicted as a fad diet. In conjunction with this article, I did my graduation project on the ketogenic diet for weight loss, a very taboo subject I might add, which was evidenced by the barrage of questions I received after my presentation. This is likely due to the fact that we were basically taught you will spontaneously combust if you implement a ketogenic diet for more than a week.
Despite my history shielding the ketogenic diet, I had never utilized this dietary pattern. Frankly, even the possibility of implementing it had never come to mind. The reason for this stems from evidence-based bodybuilding guidelines and the overall support behind utilizing a higher carbohydrate approach. Concerning the research, It has been suggested that bodybuilders should consume approximately 4-7 g/kg of carbohydrate per day. This falls in line with other recommendations falling in the range of 5-6 g/kg/d or 55-60% of daily energy intake.
In addition to this, I’ve been either massing or maintaining at least 180 lbs for the better part of 3+ years, which for me, requires a calorie intake ranging from 3500-4500. Due to the fact that I’m well aware of the reported appetite-suppressing effects of a ketogenic diet, it seemed completely impractical to even experiment with the diet considering the high likelihood it would prevent me from consuming the energy required for my goals.
While a ketogenic diet is likely suboptimal for maximal muscle hypertrophy (for more information on this check out the podcast I did with Cliff Harvey), there doesn’t appear to be any valid data or mechanism which would illustrate that it is inferior for muscle mass retention compared to a high carbohydrate alternative as long as protein intake is kept high. As such, I figured now wouldn’t be the worst time to experiment with a ketogenic approach and finally satisfy my longstanding curiosity.
My Ketogenic Diet
Ketosis is a physiological state typically defined by the amount of beta-hydroxybutyrate (BHB) in the blood. A recent scientific statement from the National Lipid Association defined ketosis as a blood level of BHB >/= 0.3 mmol/L, but from what I’ve seen, most experts in this area, like Dom D’Agostino, tend to reference a slightly higher value of >/= 0.5 mmol/L.
This physiological state can more or less be achieved through two different avenues – fasting or a high-fat, very-low-CHO diet. Shifting our focus towards the latter, there are actually a variety of high-fat, very-low-CHO diets which can be utilized to achieve the values of BHB indicative of a state of nutritional ketosis.
While a traditional ketogenic diet is quite limited in protein with upwards of 90% of calories from fat, nutritional ketosis has been found to result in diets with more liberal protein allotments and as little as 60% of calories from fat. This is the approach I elected to take since protein intake is paramount for preserving muscle mass during severe caloric restriction.
Many report that protein has to be limited in order to achieve a state of nutritional ketosis because excess protein will simply be broken down into glucose in the body via gluconeogenesis, but this has been challenged by many, including Cliff Harvey, who has been banging on this for quite some time now. As Cliff puts it, gluconeogenesis is a demand-driven process, not a supply-driven process. The body will not continue to breakdown protein simply because more is available, it will only utilize what it needs.
For my ketogenic diet, I utilized a macronutrient breakdown of 60% fat, 30% protein, and 10% carbohydrate. In the context of a 2,300 calorie diet, this resulted in approximately 150g of fat, 175g of protein, and 55g of carbs.
A standard day of eating looked something like this:
Meal 1: 2 chicken sausages, 4 eggs, ½ cup berries, 100g cruciferous vegetables
Meal 2: protein shake with MCT oil, flaxseed, and spinach
Meal 3: Quest bar and a serving of walnuts or macadamia nuts
Meal 4: Chicken or fish (salmon, sardines, tuna) salad with avocado, olive oil, and 2 servings of non-starchy vegetables
If you have been following along on this journey, you will realize that for this experiment, I kept calories the same (in actuality, I ate close to ~75 kcal more on average) and simply altered the macronutrient distribution of my diet. This resulted in 3 weeks of continued progressive weight loss.
I initially started measuring my ketones through Ketostix, which is a product that measures the amount of acetoacetate (one of the three ketone bodies) in the urine. This is typically how most people measure their ketones, at least at first. During the transition into ketosis, your body has not yet become efficient at utilizing ketones for fuel leading to excess ketones being spilled out in the urine. After a period of time on a ketogenic diet, you will become “keto-adapted.” What this means is that your body becomes adept at employing ketones as a primary energy source and as a consequence, ketonuria will cease.
With an understanding of this transition, it makes sense that once you become keto-adapted, you may very well be in a state of nutritional ketosis as measured by BHB in the blood, but a Ketostix reading may come back as negative since you are no longer “wasting” ketones or excreting excessive amounts in the urine. Rather, you are utilizing them for energy. This is why Ketostix are useful at the beginning for knowing whether or not you are in a state of nutritional ketosis, but in the long haul, it is best to measure BHB in the blood.
I used Ketostix for a week and never registered beyond “trace” amounts of ketones in my urine. This could mean two things, the composition of my diet was not conducive towards achieving a state of nutritional ketosis, or, I adapted quickly to the alternative substrate, which I hypothesized may have been the case due to my depleted state. In order to test this out, I moved on to checking the BHB content in my blood.
On any given day, my BHB levels registered around 0.4 mmol/L. As previously mentioned, according to some of the scientific literature, this value is indicative of nutritional ketosis (BHB >/= 0.3 mmol/L). Nonetheless, it is a value many die-hard members of the keto klan would scoff at. On a couple of occasions, I was able to reach the magical 0.5 mmol/L threshold upon waking but not consistently. Besides in the morning while fasted, I also tested my ketones after fasted cardio, and after fed weight training. After fasted cardio, I would pretty much always register at 0.6 mmol/L. As for post-weight-training, I would still clock in at around 0.4 mmol/L.
As an aside, I was quite interested in my BHB reading after fasted morning cardio. Even in the past on a high-carb approach, I’ve always felt terrific after doing fasted cardio. I would relate the sensation as something similar to the alertness a small dose of caffeine (about 200mg for me) provides. Perhaps this may be due to increased levels of BHB, or it could just be a result of exercise and the process of getting some blood moving.
My response to a ketogenic diet is pretty much directly in line with Dave Feldman’s Lean Mass Hyper-responder (LMHR) hypothesis. LMHRs are characterized as being “very athletic,” otherwise put, they have an active lifestyle and possess a low body fat percentage. In this particular population, Dave has noticed lower BHB levels than sedentary low carbers.
From what I have seen floating around on the interwebs, LMHRs have to consume a higher proportion of calories from fat than their less-fit peers in order to really drive up their BHB levels. Unfortunately for me, this was not an option considering my circumstances. In order to increase my fat intake while sticking to a 2,300 calorie diet, I would have to reduce my intake of another macronutrient. From the initiation of this experiment, I already reduced my average protein intake by approximately 15g and any further reductions were simply off the table.
One could argue that I should have reduced my carbohydrate intake further, but that was another idea I was not particularly fond of. I was already consciously restricting my intake of vegetables with this approach, and I did not want to eliminate them due to the beneficial micronutrients and fiber they provide. Starchy vegetables were off the menu, but even non-starchy vegetables, like cruciferous vegetables, I had to limit to 200g per day in order to keep my carbohydrates at no more than 10% of calories.
First and foremost, my transition to a ketogenic diet coincided with zero symptoms of the “keto-flu.” These symptoms emerge from increased water and electrolyte losses as a result of glycogen depletion and ketonuria and tend to reside after a couple of days as you adapt to the diet. Some strategies to prevent the keto-flu include adequate fluid and electrolyte intake, which are already habits of mine. I use salt quite liberally in my diet. I have either soy or hot sauce with pretty much all of my meals. To further prevent any potential side-effects, I supplemented with 200 mg of magnesium glycinate (any form of magnesium besides oxide is fine), as magnesium tends to be a micronutrient of concern on a ketogenic diet. Even in general, magnesium supplementation tends to be pretty worthwhile. There is no one great food source of magnesium. Moreover, good sources of magnesium include pumpkin seeds, almonds, and spinach, foods that tend to be void in the standard American diet.
Common anecdotes from those following a ketogenic diet include: improved mental clarity/decreased brain fog, improved mood, improved energy, and appetite suppression. Personally, I did not experience any of these. This may be explained by the almighty placebo effect. If someone expects improved mood, mental clarity, and energy on a ketogenic diet, their expectations can very well drive these beneficial adaptations. With that being said, I’m certainly not saying these experiences are all a result of the placebo effect, but hard scientific data on these outcomes is scant and as such, should be considered with a pinch of skepticism.
In regards to appetite, we have lots of high-quality data showing that ketogenic diets have an appetite suppressing effect. This includes trials with matched protein intake between groups. I did not experience this effect per se, which I suspect is just related to being in a chronic energy deficit, but there were subjective improvements in my hunger. While I was definitely still hungry on a ketogenic diet, the intensity of the hunger pangs was reduced. Overall, I felt much more “even” throughout the day.
A perfect example of this was how I felt after my post-workout meal. While using a high-carbohydrate approach, my heaviest carbohydrate meal was post-training. This meal typically consisted of a lean protein source, a couple of servings of veggies, potatoes, and whole wheat bread. Following the consumption of this meal, I would be HUNGRIER. In this dieted state, my insulin sensitivity is through the roof. My body is a sponge, primed and ready to suck up glucose at all times of the day. On a higher-fat post-workout meal, I may not have felt full or satiated (words which are no longer part of my vocabulary, unfortunately), but I definitely noticed improvements in hunger management over the course of the day.
My training performance on keto was perfectly fine, which was a surprise to me, especially since I had been in the habit of consuming the majority of my carbohydrates for the day in the peri-workout period. I anticipated that my ability to perform moderate to high reps across multiple sets would become compromised, but that was not the case. I was able to progress on most lifts during this 3-week experiment and maintained my performance on others.
When you look at the data, this actually isn’t that surprising. There are numerous studies that have shown improvements across a variety of anaerobic activities with the implementation of a ketogenic diet. For more information on this, again, check out the podcast I did with Cliff Harvey.
In relation to this, there is some interesting data on glycogen status which must be considered. In an excellent review on carbohydrate intake for resistance-based exercise, it was noted that an acute bout of resistance exercise reduces glycogen concentrations by only about 25-40%. Furthermore, even when no food or carbohydrate is consumed in the post-exercise period, glycogen may be synthesized. In a study by Robergs et al., subjects performed six sets of six repetitions on leg extension @ 70% 1RM. Subjects were not fed during the 2-hour post-exercise period. Immediately post-exercise, glycogen concentrations were 61% pre-exercise values. At 2-hours, muscle glycogen concentrations were 79% of pre-exercise levels.
Combining this data with research from Volek et al., which showed that keto-adapted ultra-endurance runners display similar resting muscle glycogen levels as those on a high-carbohydrate diet, and it appears that you don’t need to shovel carbohydrates down your gullet around the clock in order to have a quality resistance-training session.
On a similarly surprising note, I was quite shocked that my pumps were exactly the same while on a very-low-carb diet. Perhaps this was a result of adequate fluids and sodium, but I thought for sure the relative absence of carbohydrates in my diet, especially pre-workout, would compromise my ability to get a pump.
I truly enjoyed this brief stint on a ketogenic diet. As a result of the limited food options on keto and my fascination with consuming a nutrient replete diet, I tried a myriad of new foods which was a lot of fun. This includes some of the most nutrient-dense foods you can possibly eat such as beef liver, smoked oysters, and sardines. It’s safe to say these foods are an acquired taste (especially beef liver), but I’ve found myself to have a preference for them.
Now, for the bad. Some of the things I will absolutely not miss one bit about following a ketogenic diet are the constraints on protein and vegetable intake, as well as utilizing at least 130 calories per day on medium-chain triglyceride (MCT) oil. MCTs are rapidly absorbed and converted directly into ketones. Since they cause direct increases in ketones in the body and encourage increases in ketogenesis, they can allow the achievement of ketosis with lower amounts of fat in the diet. For this reason, I felt required to supplement with MCTs. In reality, I should have actually been consuming more than 1-1.5 Tbsp of MCT per day to support nutritional ketosis, but it feels really bad to spend hundreds of calories on oil while you’re dieting. Also, as someone who is concerned with maximizing overall health, I wanted to reserve my fat intake for particularly healthy sources like avocado, nuts, seeds, fish, and eggs.
With that being said, all of these issues are an outcome of my constrained calorie intake. If I had more wiggle room in my calories, I could have increased my fat intake to boost BHB levels, while allowing for more flexibility in protein and non-starchy vegetable intake, but as alluded to earlier, I was basically maxing out my fat intake for my unique circumstances.
Moving Forward: What I Learned From Keto
In the future, rather than going back to a diet that tries to maximize carbohydrate intake with very minimal amounts of fat, I plan to utilize a more balanced diet, at least in terms of macronutrient distribution. I really enjoyed the steadiness in energy and appetite I experienced while on keto and I hope to be able to maintain this with increases in carbohydrate intake. My plan is to basically follow the same eating pattern outlined in this article with a couple of substitutions/additions.
At breakfast, I’m going to remove the chicken sausage and reduce the number of eggs I consume down to 2. In replacement, I’ll make up the protein lost through egg whites, add a little bit of cheese and 50g of oats. I’ll continue my post-workout shake, but replace MCT oil with a serving of nuts. This will be followed by 2 Quest bars instead of one. Lastly, I’ll continue to have a big salad for dinner and add roughly 150g of sweet potato. This results in a macronutrient distribution of roughly 35% pro, 35% fat, and 30% carb.
In terms of training, this was a very eye-opening experience for me. In the end, this experiment has made a really positive impact on my psyche and has ultimately produced a more resilient lifter moving forward. There is quite a bit of power in knowing that I’m able to have very productive workouts while in a calorie deficit and without any carbs pre-training. I think many are under the impression that the stars have to align every single day in terms of nutrition, supplementation, and sleep in order to have a great training session. While checking these boxes consistently certainly helps, an off day here and there will not completely inhibit your ability to perform on a given training session. Depending on your mindset, though, you may very well be creating a mental handicap pre-training if you suggest to yourself that it is very unlikely you will have a great training session because one of the aforementioned variables was not maximized that day.
Overall, I’m very happy that I took on this experiment. I learned a lot throughout this process and even gained some insight that I can and will continue to apply moving forward.
Stay tuned for the next segment of The Battle of Biology which will include an update of my training, nutrition, and overall status as I transition out from this very-low-carb trial.
This is what happens when you remove carbohydrates from your diet and the insulin fairy can no longer exert her black magic on your adipose stores!