June 05, 2018

Fat & Fasting: Does Bulletproof Coffee Break A Fast?

I’ve been wondering lately about how Bulletproof coffee (inspired, of course, by Dave Asprey) in the morning affects intermittent fasting and my general routine of not eating other food until after 2. 

Now, I’m not super strict about going until 2 pm without eating, or doing a 16/8 or 18/6 or Warrior diet or any of the variations of intermittent fasting.  Those happen a few times a week for me, but not out of any specific intent.  I used to be far stricter when I was training for long distance running, so I'm familiar with and have used all those.  

Still, I’m curious about fat and fasting, especially for how it works with a more normal routine. 

I'll start with a disclaimer:  I use "Bulletproof" and "butter" coffee interchangeably.  I mean the same thing:  Coffee with fat in it.  This also gets called keto coffee, although my version has more protein than a true keto follower would like. 

In any event,  it doesn't matter if you're using butter, MCT Oil, Dave's proprietary blend, our cacao butter cups or just coconut oil;  for the purposes of this discussion, butter & bulletproof are the same.

Let's hammer out the question:  Does butter coffee break the benefits of intermittent fasting?

There’s all kinds of internet geekery surrounding fasting, specifically Intermittent Fasting, and I told myself for a while that my morning coffee didn’t count.  That's the "ignorance is bliss" method.  Eventually I got curious enough to sit and really think about it.

There are some obvious points:  A “fast” means no food.  Water is fine and occasional pinches of salt, but that’s it.  I know, I know.  Lots of different fasts are out there, from bone broth fasts to juice fasts (sugar it up, yo!), but I think you’re kidding yourself if you say you’re fasting when you’re taking in calories. We've done a 5 day water fast and I can tell you:  No calories is no joke.

Back to coffee and fasting though.  It's worth it to examine just black coffee by itself.  I mean, does coffee break a fast?  With only one calorie per cup, should that...count? 

C'mon, dawg.  If we're hammering out the facts, even one calorie breaks a fast.

Going without food on a water fast.

Let's look at this in two ways.  First, fasting means no food intake, and food is measured with calories, so any calories above zero will break a fast.  I know, I know, it's nit-picky, but we're better off accurately understanding the terrain if we want to successfully get where we're going.

Second, one of the reasons we fast is to give our guts a break, and coffee definitely doesn't do that.

With all that in mind, yes, any coffee, including Bulletproof coffee, breaks a fast.  Sheesh.

The big question here isn’t what fasting is (it’s obvious:  No dang food!), but what we’re trying to achieve.  Once we start to follow this line, it gets more interesting and useful to discuss the whole butter coffee, fasting, and fat burning issues.

In general, intermittent fasting is used to achieve 3 goals: 

  • Weight loss
  • Physiological (with a strong emphasis on hormonal) health
  • Performance enhancement. 
Let’s go through each of ‘em and explore how butter coffee (and especially the fat burning mocha I make) might affect the cycle of intermittent fasting as it applies to each goal.

People fast for different reasons, usually weight loss, muscle gain, or increase physical performance.

First, weight loss.  You probably want the BLUF (Bottom Line Up Front):

If you’re fasting for weight loss, then drinking butter coffee in the morning probably won’t affect the benefits of intermittent fasting for you. 

Your aim with IF (intermittent fasting) for weight loss is to

  1. Decrease caloric intake
  2. Restrict caloric intake to a reduced feeding window
  3. Upregulate (that just means convincing your body to increase production) beneficial hormones and energy systems.

Butter coffee adds calories, but in the form of fat.  Paradoxically, those fat calories aren’t what make you fat, especially because they’re not paired with high sugar or carbohydrates. 

In the case of buttered coffee, the extra calories from fat seem just fine.  Additionally, the pairing of fat and caffeine seems to help in burning more fat, and for me, in smoothing out the effect caffeine has on my system. 

That’s an N of 1, but I’ve heard about that same "smoothing" effect anecdotally from a bunch of other folks.  The bottom line is that it works for me.  Black coffee + me is a disaster unless I immediately go for a hard workout. 

Weight loss is more complicated than counting calories, but drinking butter coffee in the morning seems to depress that hungry feeling for a long time; until noon for some, later for others.  If you're not hungry, you're not eating, and if you're not eating it gets a lot harder to take in calories.

In the second instance of restricting calories to shorter feeding window, my feeling is that butter coffee helps with this.  Once I drink it I’m not truly hungry until late in the day.  Sure, I’ll get all emotional and eat based on being a rudderless sucker when it comes to available food and something to do, but I’m not actually hungry until well past 5 pm.

If I'm eating just one meal a day, I've found it's hard to actually eat enough food to sustain serious physical effort; my stomach just isn't big enough to comfortably take in that many calories at one sitting.

It's going slightly off topic, but the short version of how I use intermittent fasting with physical exercise is this: 

  • I drink butter coffee every morning.  
  • I eat dinner every night. 
  • On days that I work out, I open up my feeding window and usually add a small amount of food within 30 minutes of the workout, say, a can of sardines and a handful of berries. 
  • On days I don't workout, that feeding window is pretty much between 6 PM and 8 PM.

It's simple, effective, and I stick to it fairly loosely.  If a Bandito is calling to me at 2 pm, I'll eat the damn thing.  True IF types and the keto-cult will kick and scream, yelling "That's not keto!"  That's fine.  I know what I'm doing, I've tested my ketones with blood and breath, and with this method of generally not eating that much but not being super strict, I maintain a healthy balance of burning carbs and ketones.  

Not actually hungry until after 5 pm

In the third case of using intermittent fasting for weight loss we're aiming to upregulate hormones and energy burning systems for weight loss. This is basically butter coffee’s claim to fame and extensively covered by all kinds of questionable but enthusiastic amateurs. 

I think it’s pretty safe to say that drinking butter coffee for most people isn’t going to work against their weight loss goals.  In case you’re wondering, I’m not a doctor and this does not constitute medical advice. 

Ok, so that’s weight loss. 

Basically, butter coffee for weight loss is a benefit, as long as the caffeine and fat agree with your gut.  Those three have a glorious and joyful relationship in my body, but my web developer’s gut is markedly different from mine, and caffeine plus fat  puts him in the bathroom, stat.  Hell, maybe it’s a good thing for cleaning out his system, but that’s another story.  Obviously, your results will vary. 

Now we come to physiology and whether or not butter coffee in the morning breaks up the intermittent fast in a way detrimental to the goal. 

Let’s start with the biggest picture that’s still useful:  Humans have a complex variety of reactions with regards to hormones, food, and the environment. 

Hormones, food, and the environment all have an effect on each other in a reinforcing cycle

If you’re generally healthy, butter coffee seems to promote more beneficial than detrimental observable reactions in my experience.  Again, that’s not an absolute, there’s very little science investigating that, and I’ll bet anything I get at least one self righteous screamer telling me that this is irresponsible advice.  If that’s you, or you’re worried about this, don’t drink butter coffee. 

With that in mind, let’s talk about what we’re aiming for physiologically with intermittent fasting.  When you fast intermittently, you’re basically starting to follow your evolutionary blueprint. 

Most people don’t follow their blueprint, which leads to all kinds of problems, many of which can be addressed by coming back to the “2 million years of evolutionary pressure” perspective.

Again, the idea of what happens at a chemical, hormonal, muscular, and gut level has been exhaustively covered through the internet. The basic thrust is that stopping eating for a while gives your gut and body time to rest, recharge, and prepare to digest the next round of food.

This is probably the most likely candidate in the reasons not to drink butter coffee when intermittent fasting, as there’s no pretending that butter coffee doesn’t need digesting. 

In fact, the recipe for butter coffee that I use includes 3 different fats (butter, coconut oil, and cacao butter) 2 different powders (a mushroom blend and BUBS collagen) and an egg, and there’s no way all of that doesn’t need energy to digest or isn’t a disruption to some hormonal and physiological systems that would otherwise get to rest if I didn’t drink it.

So, in the case of hormone balancing and general physiological disruption, butter coffee as part of an intermittent fasting routine probably isn’t the best thing for you. 

Still, I’ve been drinking it for a few years now, am ultra stoked with how I (in the immortal words of Robb Wolf) “Look, feel, and perform” and the few blood tests I’ve done come back showing me generally to exceptionally healthy (depending on the background of the doc reading the results.) 

Finally, let's talk about how breaking your intermittent fast with butter coffee might be a performance enhancement. 

This is where butter coffee seems to have the strongest case for being used in conjunction with a general pattern of intermittent fasting. 

If the goal of IF is performance, and performance is achieved by in general having a happy empty stomach and lots of useful energy, then butter coffee is (in my experience) a superb addition to the performance enhancement routine.

With butter coffee I have very productive mornings, very little need for food until dinner, a great appetite at the end of the day, excellent sleep, and plenty of energy to get under the bar and drive out of the hole a few days a week.

If you’ve been zoning out as you read this and daydreaming about paleo desserts or how to justify adding a Cacao Now to your evening routine like Lee, let’s sum up this whole thing:

By the book, butter coffee breaks a fast.  This would be the de jure side of the argument. 

However, the world we live isn’t one of strict rules, so the de facto side states that despite it breaking the rules of intermittent fasting, overall, adding butter coffee to your routine is probably a net benefit. 

Happy drinking, amigos.  Oh, you want to know more about fasting?

If you want a video on how I geek out on making my butter coffee every morning, it’s here. 

If you want to know what coffee I grind & drink every morning, it's right here.

Want to know what it's like to drink $900/lb coffee?  Yep, I wrote about that too.

If you want to "make it a mocha" without all the sugary syrup crap, here are the cacao butter cups I use in the video.

To excellent mornings, delicious coffee, and your health!


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Nik Hawks


Nik Hawks helps run the show at Paleo Treats. Fascinated by humans in all their strange glory, Nik is harnessed in and pulling hard in pursuit of excellence with the rest of the PT Crew. Enjoy!

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1 Comment


June 11, 2018

I researched IF after trying it for a while and found an NIH research paper that said IF does hold promise for weight loss, but also seems to lower testosterone and IGF-1 levels. They recommended additional studies to understand why this was happening and it’s long-term impact. Something to consider – butter coffee aside. It shouldn’t be hard to find the paper if you just Google those terms.

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