On a personal level I have not had the best experience with this. Normally when I IF, it's because I'm lazy and just not very hungry in the morning. Coffee is one of the few things I desire and the butter-MCT-coffee method gives me crazy energy. Unfortunate about the crazy part. I will feel very very very crazy, like a manic state, and then I'll crash around 1 PM. I've had to brute force myself into breakfast lately.

I'm female, I do 18/6 IF, and I eat very low-carb/high fat. And while I can eat lots of fat with no problem, I just can't deal with bulletproof coffee. Even after drastically reducing the quantities of MCT oil and butter, it made me feel nauseous (and screwed up some perfectly good coffee).

It's a morning thing. I've never been a breakfast eater, either--the last thing I want in the morning is food. So I wake up, have my strong, black coffee, and I'm fine fasting until 6:00 PM (which, given my schedule, is equivalent to lunch for a normal person).

My weight loss has been slow--I'm 45, and hormones are not on my side. But even though I don't like being a fatty, I'm cool with it. I'm doing all this for health reasons, and have already seen tremendous improvements on that score that make me very happy, and much more optimistic about my future. And if I continue, eventually I will be lean again, and it will be because I'm healthy. So I don't really feel the need to keep hacking weight loss any further (which is kind of amazing, when I think about it). I'm not losing weight to get healthy; I'm getting healthy, and weight loss is one result.

Don't know if it would solve the female IF dilemma since my understanding was that the main problem with IF'ing was the cortisol spike doing more harm to the female hormone balance. Wouldn't the coffee spike cortisol just as much (if not more?)

Bulletproof coffee didn't help me at all with IF. I just got shaky and felt somewhat nauseated for a few hours after waking up. Of course, IF didn't work out for me either so I can't blame it all on the coffee-- turns out I am just a breakfast gal!

Additionally, I wonder if slamming a MCT-laced/butter-infused /caffeinated cocktail is really effective at sending the message to your body that there is an abundance of food... if you're body is under the impression that it is starving it seems that a super fatty cup of coffee is hardly going to convince it otherwise.

Immediate Disclaimer: I am not a woman.

Though I do not sport the same gender and accompanying milieu of temperamental hormones (sorry, it's true though, the ladies have a much harder time dropping body fat), I do have a something to offer on the matter since I have fasted for over a year and my mother began inadvertently fasting several months ago.

With that said, I do not see any negative benefits of prolonged fasting unless I'm eating poorly, which I would not recommend to anyone regardless. My mom on the other hand notices that she starts to feel "off" in general if her daily fasts extend beyond 15-ish hours. She really enjoys a general protocol of finishing eating around 7:30-8:00 and having a large-ish breakfast at approximately 11:00-11:30. She generally does have a bit of coffee in the morning (black: no milk, cream, or sugar --she and I share that quality), so that may help the fast go smoothly.

So, I would suggest that you give it a shot both ways; that is, try a true fast for around 14 hours without any additives in your coffee and then give this "bulletproof fast" a shot. Speaking to the latter though, if body fat loss is the main goal, I don't think it's logical to put 4-800 calories worth of energy into a liquid you plan to consume, regardless of the health properties of those foods (butter & MCT oil). Perhaps that's just my opinion --which may or may not be skewed by that fact that I believe Dave Asprey to be arrogant and obnoxious-- but I think it's a valid suggestion.

Best of luck Julia,
-Ian

I make my own version of this, which could be named "bulletproof decaf chai", but isn't because well, that's stupid.

I don't do caffeine.

I've consumed it for approx 4 months, and it contains roobois chai tea, coconut oil and MCT oil. (I use I TBSP of each).

Has it helped me lose any weight? I'm going to say no. Does it keep me from getting hungry? Sure... however in the past 2 weeks I swapped it out for just the rooibos chai tea, and it also helped me from being hungry and I've noticed that I have lost weight. I'm not really trying to lose any more fat, so I'm now tempted to just eat a small breakfast of something fatty and delicious.

Edit: My suspicion is that very low/zero carb folks that use mostly fat for energy have the easiest time with this, because for us it's almost like a liquid fat meal... and to me it isn't true IFing.

please enlighten us not in the know what "bulletproof coffee" is. Details without acronyms. Thanks!

I find it does help me. I have a tendency not to want food in the morning, and while at first that was a benefit to losing weight, recently I stalled for quite a bit. I replaced my coffee with heavy cream for Bulletproof coffee, and I started losing weight again. I think that I did need some morning fat, some more calories, but forcing myself to eat wasn't the answer.

I find I get great energy from it, and it's delicious. I also drink less coffee on it. I am a total coffee and tea fiend, and while I can have my tea with coconut milk, I don't like coconut milk in coffee. I think I was drinking too much coffee with heavy cream before.

Everyone is different, so I can't say how it will work for anyone else, but I'm going to keep using it, and watching my progress. I am all for personal experimentation, and there are tons of different things that may or not work for me, and the only way to find out is to try them.

Female here. I regularly stop eating at about 6 pm. Have coffee with 150 cals worth of coconut oil in the morning, and don't get hungry until at least noon. It feels healthy to me, I have no energy problems, no symptoms from it, but weight loss for me is consistently slow, so who knows if it is good or not.

I'm female and usually "fast" for roughly 15 hrs (8-9 pm to noon-1 pm) 4 days a week (the days I go to work). I don't do bulletproof coffee, I do drink a big cup of coffee with a lot of coconut "cream" (the thick, fatty layer at the top of the can) in it in the morning. I'm doing a Whole30 now, prior to Whole30, I used heavy cream from grassfed cows when I was feeling rich, commercial half-and-half when I was not. When lunch time comes, I'm definitely hungry and ready to eat, but not starving, shaky, etc.

When I started doing this (maybe 3 months ago?), I dropped 4 lbs in a week. Fat loss has slowed but continued. Of course this "fasting" (sorry for the repeated quotes, but it's really not a fast when you consume 3 Tbs of fat in the middle of it) isn't the only variable in my diet -- I've been watching the fruit & nuts, and am now on day 25 of the Whole30 which is pretty restrictive, and is definitely contributing to recent fat loss. So I can't really say if it's cause and effect, but I'm happy with it and it certainly doesn't seem to be hurting me.

I was completely skeptical about bulletproof coffee (not to mention extremely grossed out) but my inner nay-sayer got beat down on this one. Following the guidelines for buying the proper coffee, I picked up some beans at Four Barrel coffee, reduced the fats to 1 TBS each and used ghee (grass fed) instead of butter.

The result?

A nice, clean energy rush that lasts most of the workday. No crash. No headache. The headache thing is really worth noting - I rarely drink coffee because it gives me awful headaches. As a drink, lipid-laden coffee not nearly as gross as expected. I'd give it two thumbs up if there was some way to ice it, but that's just me.

Say what you will about Dave Asprey (Mr. Bulletproof), but maybe spend some time on his site before passing judgement. Sure, he sells some of the stuff he talks about. But he also tells you exactly what you need if you'd like to source the stuff elsewhere. I live within walking distance of single origin, wet-process, South American coffee grown at altitude (variety most likely to be free of mycotoxins) so no one but me & a local roaster profited from my coffee experiment. I, for one, am quite grateful to Mr. Bulletproof for sharing :)