my thoughts on ketosis after a 72-hour fast

First things first: I am not a medical doctor. My understanding of the things I intend to address in this post is extremely limited and I write about them only out of sheer curiosity. I have developed quite an attraction for the self-experimentation-oriented type of mindset that is modeled by such people as Tim Ferris and Peter Attia. Needless to say, I do not possess the credentials or the expertise of such people. I was a lowly English Literature major in college and am now preparing to attend law school; similarly, I have not engaged in ultra-endurance type activities (like Attia) or achieved world-class status as a tango dancer (like Ferris). I do, however, exhibit a similarly curious frame of mind as these folks, and I also digest theirs and other experts material with relentless vigor. My knowledge regarding ketosis and the related science has increased greatly, revealing new, deeper, more challenging questions. I think there are a number of fascinating theories and hypotheses popping up in this space and I want to do what I can to help push the ball forward.

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Back in May, I wrote a short blog post describing my first week of experimentation with a ketogenic diet. My goal had been to undergo a twenty-one day, no exceptions, ketogenic trial, and then to report weekly on my blood markers, behavioral observations, and whatever else struck me as interesting about the experiment. Alas, life intervened. I made it through the trial, but failed to report on the second and third weeks of it on this blog. Now that I am back in Massachusetts, however, and now that much of chaos in my life has dissipated, I am hoping to make this blog more active. I have a number of mini-trials in mind, starting with this one, a 72-hour fast. Let me tell you about it.

WHY FAST FOR 72 HOURS?

Anyone interested in the ketogenic diet or the paleo diet or any other increasingly popular method of metabolic manipulation probably understands that we have been misled with regards to carbohydrates and dietary fats. The title of Gary Taubes's 2002 article in the New York Times was "What if It's All Been a Big Fat Lie?" Such a great title--considering what we had been told was, in fact, facetious. The nutrition community promoted the notion that saturated fat caused heart disease and subsequently told everyone a story about "low-fat" diets being the key to losing weight. Thus, dietary fats were vilified and people starting eating a lot more breads, pastas, and other "healthy" carbohydrates. That was about half-a-century ago. We've seen the results--they are in. Anyone willing to pay attention will notice that the advice was dreadful--utter misinformation: carbohydrates (and the attendant sugars) tend to make us fat and sick, not lean and healthy. 
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I've come around to this shocking (sort of sickening) understanding over the past year or so. Last summer I started cutting back on carbs, eating about 100-150 grams a day. (A fairly significant reduction when compared to the Standard American Diet (SAD)). Then, as you know, I started getting into the ketogenic approach. Here's the thing: this first understanding--that limiting carbohydrates is a good thing for one's health and longevity--has become the baseline for me. Set in stone. Now, I want to see what else can be tweaked, to unlock the greatest possible metabolic benefit. There are a number of different suggestions being made by such investigators as Valter Longo, Steven Phinney, Dominic D'Agostino, Rhonda Patrick, Mark Scisson, and others, but each of them seem to converge, to one degree or another, on the notion of caloric restriction. Recent studies involving rats and mice have demonstrated marked effects from an overall reduction in calories. BUT--aye, here's the rub--many of these experts remain highly skeptical about general caloric restriction being the solution for human beings. I will not get into the reasons for this belief here, because it would take me quickly outside the scope of this post. What I can say for now, however, is that the resulting strategy from this dismissal of overall caloric restriction is quite clear. The plan of attack, simply stated, is something like this:

1) Isolate those effects that caloric restriction has on animals that appear to be good for longevity and health.
2) Devise or discover nutritional approaches and techniques that mimic the effects of caloric restriction. 

(Damn, I feel like I'm writing that phrase a lot. Once more: CALORIC RESTRICTION. Okay, good.)

If I am making any sense so far, you're probably wondering, What are some of these strategies that researchers think mimic an overall reduction in caloric intake? 

Well, that's the crux of the ongoing intellectual debate, the scientific investigations, and the amateurish n of 1 experiments I deign to explore. Here's the three primary alternatives I have encountered thus far: 

1) Ketogenic diet (an eating plan; includes exogenous ketones)
2) Intermitent fasting (periods of caloric restriction)
3) Metformin (a drug)

Hopefully I'll get my hands on some metformin one of these days and be able to do my own experiments with it, but for now, my focus sits squarely on the first two techniques. As I mentioned above, my foray into the ketogenic diet has been ongoing. My next self-experiment will consist of a longer bout of a strictly monitored ketogenic diet. Funnily enough, I switched my emphasis to intermitent fasting partly out of an increased engagement with Valter Longo's work, but mostly because Peter Attia mentioned last week that he was doing a week-long fast, so i decided to try one for three days. Here's how it went. 

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Some Results and Thoughts from those 72 Hours

The fast began on the night of Sunday July 22 at 5pm. I had an early dinner around 4 o'clock--chicken fajitas--and by 5 I had entered the fasting state and resolved to ingest nothing but water and black tea (with a few additives) for the next three days. 
 
That night before bed, I measured my starting levels of glucose and blood ketones (BHB, in this case), as well as my body weight. (If you don't know what I mean by blood ketones you should check out my earlier blog post--or, better yet, any podcast featuring Dom D'Agistino.) These are the levels I recorded that first night:

Glucose = 5.33 mmol/l
Ketone = 0.6 mmol/l
Weight = 160.0 lbs

As expected--I had been eating more of a slow-carb type diet than a strictly ketogenic diet--glucose was providing the majority of my fuel. Even 0.6 was fairly high for my ketones to be. Most people would consider that being in ketosis, but for me, because of my constant minimization of carbs, it's kind of average. When I was eating on a more reigmented ketogenic diet, I saw that number go well over 1.0 mmol/l. Having made note of the data, I went to sleep excited to see what happened as I began to enter a more deeply fasted state. 
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Rather than present the rest of the blood data in a piecemeal fashion, I'll throw up a graph of my Glucose x Ketone and then talk about it. (I'll address body weight at the end.) 

As you can see, my blood ketone levels went steadily upward for the duration of the fast--with the exception of the slight dip when I checked my levels right before eating on Wednesday night. (Not sure what to make of the dip...) The converse was true for my glucose levels: going steadily downward for the majority of the fast, with a slight uptick toward the end. 

One thing I had wanted to see was whether I could get to the "flip-point." Meaning, the point where blood ketones are providing more fuel to my body than glucose. Tuesday evening and Wednesday morning were the times when I came closest to achieving such an end, but it did not manifest. I did not make it above 2.8 mmol/l in ketones, nor did I dip below 3.38 mmol/l in glucose. Slightly disappointing, I'll admit, but still encouraging. Never before have my blood ketones gotten so high as they were Wednesday morning, 60-62 hours into the fast. What this proves is that my body can produce that many ketones, even (in theory) on a ketogenic diet, if I can structure it adequately and monitor it sufficiently.  
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Above I mentioned drinking only water and tea for the duration of the fast. I want to be up front about exactly what I consumed, partly because it might explain the dip in ketones toward the end, but also because I want anyone thinking of trying a fast of their own to consider using some of these techniques--at a bare minimum. 
The supplements I am about to mention were always consumed in my tea. Here's a table depicting the different things (by serving size) I included in each cup throughout the fast:

Notably, my last supplement was consumed on Wednesday morning, possibly explaining the reduction in ketone levels that night before dinner. (I hope to write much more in the future on both MCT (Medium Chain Triglycerides) and exogenous ketones. For now, I would simply recommenced that anyone experimenting with fasting and/or ketogenic diet procure a bottle of MCT oil from Whole Foods or some other retailer. It really seemed to help me out.) 

What most people probably want to know, though, is how I felt! Am I right? 72 hours without food must have taken quite a toll, been quite a burden, driven me crazy?! 

Next time I do more than a 24 hour fast, I'll be keeping a journal so that my self-reflections can be more contemporaneous. For now, I'll say this: I actually felt pretty damn good! Of course, there were utterly debilitating moments of agony (mostly mental) where I doubted my ability to continue, but these were few and far between. It's actually completely crazy: I realized in the midst of this that I had never, in my adult life, gone more than twenty-four hours without eating something. (I was in the hospital for an extended stay once where I didn't eat for a while, but that doesn't count, I wasn't particularly attentive to my lack of sustenance then.) I'll try to delineate some more of my feelings at various points in the fast, briefly.

Waking up on the Monday morning, I felt fine. In the past few months I have been playing around with 16 and 18 and 20 hour fasts, so my body wasn't completely shocked when I skipped breakfast and jumped right into my day. Passing lunch, I was beginning to feel some rumblings down below, but nothing I couldn't handle, I powered onward. 

My wife enjoyed her dinner (which I cooked) and I sat there with my tea, sipping and sipping. Even then, it was difficult, but I didn't doubt my ability to continue. My ketone levels were still below 1.0 mmol/l, but I felt fine. (One thing I did notice that night was I had a bit of trouble falling asleep. This was most likely due to an upshot of cortisol in my system, set off by the panicked state my body now found itself in. When I woke on Tuesday morning, I made tea, and kept on going. 

Tuesday was worse. Oh yes, it was much harder. I was not unable to function, but I was quite viciously hungry. A few times, I found myself poised over a jar of peanuts, ready to snag just one, or two. But I didn't. I kept going. And then, toward the evening... I no longer felt hungry. Honestly, I felt pretty damn great. My wife ate her dinner and I sipped my tea, content. Upon checking my blood levels I was encouraged by the proliferation of ketones flowing through my body and the relative lack of glucose. I still had a bit of trouble getting to sleep but it wasn't nearly as bad as the night before. 
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Wednesday was much like Tuesday evening. I was fairly content all day. The grumblings in my stomach had largely dissipated and with just one cup of tea and a single serving of MCT oil I made it to dinner time and broke what turned out to be a 73 hour fast at 6pm that night. My first three day fast was over! 

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General Conclusions and Contemplations

The biggest question in this space at the moment--at least as far as I can tell--has to do with the generalizability of these metabolic-based therapies. There is ample evidence for the idea that a (properly formulated) ketogenic can be helpful for people with epilepsy. Various types of seizures, as well, are mitigated when subjects enter into a state of nutritional ketosis. No one would dispute the efficacy of this technique when it comes to alleviating ailments such as these. What has yet to be proven, however, is the more general utility of eating a ketogenic diet or engaging in periodic fasting. Can such techniques be useful for so-called "healthy normals?" Meaning, those of us who do not have epilepsy or struggle with obesity or suffer from seizures. My hypothesis is that it can be useful for very nearly everyone, and that's partly why I am so eager to conduct these n of 1 experiments on myself. 
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My wife's father expressed some genuine concern for my health at the outset of this particular experiment--and for a potentially good reason. I am only a 160 pound guy, already eating low carb, and I do not have particularly ample body fat to spare. He worried that I might run into a problem with energy levels or rapid weight loss, or something of the like. I tracked my weight throughout the fast, and here's what happened: 

As you can see, I lost nearly five pounds by the peak of the fast. Much of this, no doubt was water weight, but still, I found myself slightly concerned (probably due, in part, to the concern I felt from those around me) at times about the downward trend. Obviously, my goal is not to lose body weight. The question, of course, centers around what type of weight I was losing.

The ketogenic diet has been shown to inhibit mTOR (mammalian target of rapamycin) in the body. Keeping mTOR levels at a minimum is a large part of the reason a ketogenic diet is thought to improve longevity (it delays the aging process), but a very real concern about limited mTOR has to do with muscle growth. mTOR is vital for the production and maintenance of muscle tissue. So, it is possible that my mTOR levels remained quite low throughout the duration of the fast and that I was beginning to lose muscle mass as a result. In the near future, I intend to pursue a long-term, well-formulated ketogenic diet experiment, paying closer and closer attention to muscle loss/gain. I have heard many interesting ideas about tweaking the body to utilize mTOR while working out and keep it repressed otherwise. This is perhaps the most important topic in this area and I will be returning to it again and again, no doubt. 
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I am at a bit of a loss as to how to end this post. Whether or not I have managed to say anything useful in these lines can be left to the reader to decide. All I know is that my interest in fasting/ketogenic diets and other metabolic manipulation techniques remains deep and vast. I am convinced that anyone interested in longevity (both healthspan and lifespan) should be paying close attention to this area. There are a number of developments and investigations underway at universities and facilities across the globe. Perhaps in my next post--while I begin my new, amped-up ketogenic diet--will center around this research. Maybe I'll build a bit of a hub for anyone interested in the most recent experiments and observations, with links to relevant pages and journals. Thanks again for reading. Let's keep on getting better--even if we don't know exactly what that means!