Three weeks ago I started a keto diet for reasons I’ll explain.
This blog is simply my experience on it, what worked, what didn’t work and a bit of science to read if you’re that way inclined.
I’ll follow this up in Part 2 with some data to show a summary of the changes I experienced with a higher carb but calorie and protein equated approach, and some considerations to help you choose which will work best for you.
Bit of a caveat here;
Tracking performance changes when in a hypocaloric diet is already likely to show a loss in strength.
This is the biggest, stupidest problem with this whole blog post. I’m not afraid to admit that the timing of this experiment / experience was dumb. (Even if my intentions were pure.)
TL:DR
1. Keto diets can provide specific lifestyle benefits however, it may not suit your chosen training style or training goal.
2. I don’t know if my results would have been different if I were eating at, or above maintenance
3. I do know that a hypocaloric ketogenic diet SUCKED BALLS for my performance
Also – n=1 is not a scientific study.
Read what I have to say as something which is “interesting,” but pretty unscientific.
(Although I do give you some science to read.)
So why did I start a keto fat loss diet?
Six weeks ago, a very high level and highly valued client of mine began a hypocaloric ketogenic diet to drop body fat.
One of my pet peeves, is coaches asking their clients to do things which they have never experienced or done themselves.
The same as I wouldn’t see a video on YouTube, or an exercise that another PT is giving to their clients and just give it to my client because it looked “fun,” I have always avoided utilising tools for nutrition and programming which I have not personally experienced. Simply because I don’t know what you’re going through, I don’t know what cues to provide or how to adequately communicate what you will be experiencing, and I haven’t lived it therefore I don’t understand what pitfalls, challenges and benefits you’ll get. Worse still – I might butcher the fuck out of that exercise and in my ignorance, coach you how to do it incorrectly and give it to you when you don’t fucking need it, or it’s not right for you. Which is unfortunately, what I see with other coaches all the time.
So having never done a ketogenic fat loss diet personally, I decided that I wanted to know what my client was going through in order for me to truly understand her experience.
I know how to structure a ketogenic diet, but I cannot coach if I don’t know. So I needed to know.
Studies on Ketogenic vs Western diets for PERFORMANCE give mixed results
There is one particularly poorly received study which has pitted ketogenic diets against higher carbohydrate diets. This study by Wilson et al released earlier last year made a couple of claims which weren’t really backed up by the data. Specifically, that a keto diet provides advantages over a higher carb diet for both body composition and performance. Both groups had similar results over the 10 weeks prior to the final glycogen loading period, which skewed the data towards keto dieters as DEXA scans will show increased glycogen and water as lean tissue. (Adel Moussa does an excellent review of the study here.) One of the benefits of this study however, was the use of trained individuals whom had a minimum 1.5x bw squat, which is most relevant to my experience of ketogenic dieting and powerlifting.
Somewhat less relevant, because of the use of non-trained individuals, was this study by Urbain et al (2017) which found a small reduction in peak power, exhaustion and endurance, and concluded that “Our findings lead us to assume that a KD does not impact physical fitness in a clinically relevant manner that would impair activities of daily living and aerobic training. However, a KD may be a matter of concern in competitive athletes.” Interestingly, these subjects were also in a hypocaloric state (energy deficit) so therefore this may have further impacted results.
Given that I dropped nearly 3kg of weight in 3 weeks, this would likely have been further impacting my performance results on this diet also. If we were looking at my experience as a scientific test, you’d rightly pick up on this and use it as a criticism of the outcome. Anecdotally, I have experienced HUGE gains in strength on a hypocaloric, moderate carbohydrate diet in the past, but n=1 is certainly not the basis for scientific inquiry.
An older study in 2014 on the use of ketogenic dieting for power athletes showed that there was a similar increase in strength and performance.
This case study was publicised in 2017 showing enhanced feelings of well being but reduced performance in endurance athletes. Not particularly relevant to my experience due to the different methods of training, and given the fact that this was a case study with no control group, we have to consider it an interesting, but not particularly weighty insight.
In an interview with Science Daily, Edward Weiss, Ph.D., associate professor of nutrition and dietetics at Saint Louis University commented that “This diet is especially hot among people who are trying to optimize their health. What this study tells me is that unless there are compelling reasons for following a low-carb diet, athletes should be advised to avoid these diets.”
One major issue with this statement is that the study he is drawing this inference from only had subjects following the diet for only four days.
In an excellent review on Sci-Fit called “The Ketogenic Diet’s Impact on Body Fat, Muscle Mass, Strength, and Endurance,” they review a number of studies and their limitations (small sizes, endurance vs strength athletes, lack of isocaloric and protein matched studies etc) and conclude that;
“Overall, we need more protein and calorie-matched studies that also measure ketone bodies. With these limitations noted, keto groups did maintain or increase their strength in the studies. Though, typically not to the same extent as the control group. This is promising because it suggests that a ketogenic diet doesn’t have to entail a loss of strength, but it also implies that people looking to maximize their strength should be careful about choosing keto.”
Credit: Sci-Fit
What I learned about a ketogenic diet – from a lifestyle perspective
It was far easier for me to find meals outside of the house, and far quicker to cook food than I had anticipated. It also provided a number of lifestyle benefits in that my appetite was so reduced, that food no longer took up any of my mental energy. In fact – as someone who thinks about food more than I would like to – I found that taking that focus off food gave me more focus to place elsewhere. I would attribute this equally to a) reduced appetite from consistently low blood sugar, and b) boredom from eating the same. fucking. food. all. the time. There’s no change in texture with keto. Everything is greasy. Nothing is fluffy. Nothing is bready. Nothing is really chewy. It’s meat / avocado / greens / eggs and cheese Groundhog Day. Ughhhhhhh.
My mental energy is different. You have more consistency with your train of thoughts, less likelihood of being distracted, more focus upon one thing at one time. When it comes to learning or retaining information, or even relaying information in my sessions – keto was brilliant. I’d attribute this simply to the lack of blood sugar swings, and the consistent energy release which a higher fat diet provides.
So all in all, mental and emotional fluctuations were minimal if non existent, as was my appetite.
I often found myself having to “force” myself to eat, or to remind myself to eat more so that I could actually get enough calories in. From a sleep perspective, I had no changes to the depth or the duration of sleep, and no issues getting to sleep.
Digestive-wise, I chose to get 50g of carbs and made sure that each day I had at least 30g of those carbs from fibre. So safe to say, I did not suffer from the constipation most keto dieters complain about and my poops were as glorious as ever.
This also held off the “keto flu,” as my potassium and my sodium intake was balanced throughout. I had no problems with energy day to day, only during higher intensities of training.
In fact, one of the coolest things I noticed when I was training was the way in which I felt “in” my body. I was completely connected to, and conscious of where every muscle was positioned, how I was moving, how I was bracing, breathing and performing. Unfortunately – this extra mental focus didn’t help my performance.
To summarise, this style of diet would highly suit someone who doesn’t have much time to eat meals and wants to stop snacking behaviors or giving too much energy towards thinking about food. It would also be very suited to people who have long work hours but cannot leave their desks very often, and need to be on top of their game mentally. If you are sedentary, this diet is very effective as if you are not highly active nor interested in boosting your physical fitness, you do not suffer from a lack of carbohydrates.
If your aim is to get fitter or stronger – I cannot honestly say with any confidence that a zero carb approach is going to work – and neither can the current science.
What I would need to do differently if I were to give Keto a fair go for performance…
Because I was in a calorie deficit, I would likely have been weaker anyway. (Although, as mentioned – I have improved both body composition and strength on a hypocaloric, higher carb diet in the past.)
However – I keep having to remind myself that performance wasn’t the reason I was doing it. The reduction in performance was just the reason I STOPPED doing it.
To quote myself from earlier on in this blog;
So having never done a ketogenic fat loss diet personally, I decided that I wanted to know what my client was going through in order for me to truly understand her experience.
I know how to structure a ketogenic diet, but I cannot coach if I don’t know. So I needed to know.
N does not = 1, but maybe if you give a fuck about getting stronger – there’s something valuable here for you.
What I learned about a ketogenic diet – from a performance perspective
Chatting to a client this morning, I used the following analogy;
“I’d liken it to having a car with a turbo, but when you try to tap into that top gear a bunch of rats just jump out of the engine.”
Very driven, very consistent and very determined to improve each week.
The final week I lost strength on my bench, my deadlift AND my squat. And despite giving it 100%, I simply had nothing left. Weights which should have been a warm up were now my 2 or 3RM. Weights I was smashing with gusto just a month prior were now like pulling teeth out without anesthetic. Getting out of the hole in a squat felt like trying to run through knee deep mud. Never in my life have I felt so hopelessly weak despite working so hard to be strong.
My perceived rate of exertion went through the roof. I also found that my heart rate, which normally is around 60BPM at rest and then only moderately high at 120BMP during higher intensity, lower rep strength training – went through the roof during 3 rep sets. My heart rate spiked far higher, far more frequently and quicker in the session than usual, and took far more time to come back down.
Collecting data over this period using a wearable was instrumental in showing me what wasn’t working – here’s a contrast of September to October; during September I was smashing multiple PB’s, both from a volume and an intensity perspective, and eating over 250g of carbs per day. (More on specifics of my nutrition pre and post to come in Part 2).
But I did not expect them to be of this magnitude. I did a lot of research going into this and spoke to many people. So I had both an academic perspective and also an anecdotal one which led me to believe that powerlifting, or strength increases, were still possible despite a lack of carbohydrates in the diet. I found inconclusive evidence, and experts who believed that I could still get stronger without eating carbs – but for me, in reality, this wasn’t true.
It may be that this is an individual thing, but I’m tempted to say that’s a load of shit. Anyone who has gotten stronger on a ketogenic diet may actually find that they would be even stronger if they ate carbohydrates. Until you’ve tried both styles and kept calories equated, you simply don’t know.
Unless you have tried to get stronger eating both a high carbohydrate and a low carbohydrate hypocaloric AND maintenance level or hypocaloric diet – you cannot honestly say you know what works for you.
From here
Total calories and protein are equated, but the ratio of fats to carbs is changing.
I’ll post Part 2 in 3 weeks (to give both approaches equal time) and track data to see if one diet style performs better for me on a performance / powerlifting basis than another.
One major factor which is going to fuck any true scientific method up is that I’m no longer doing a peaking phase, so the volume and intensity will change between my keto approach and my higher carb approach. I will be going back to a more hypertrophy style of training which is more glycolytic and more suited to carbohydrate intake. So carbs are now going to be given an unfair advantage I guess. (Having said that, very low reps / high intensities aren’t particularly carb intensive either – so maybe not?)
So although this isn’t a rigorous scientific study at all, it can be what it is – a simple blog to outline how I felt and how I performed on each dieting style – in a hypocaloric setting.
I can provide some feedback on the lifestyle and performance changes I felt, how my heart rate changed, digestion, biofeedback markers ie hunger levels etc. which may illuminate some factors to help you to decide if you want more or less carbs in your own approach. As a coach, I also achieved my aim which was to understand what my client(s) are going through and to help future clients make nutritional choices which reflect their individual needs and lifestyle.