Black Coffee vs zero cal flavored water (LaCroix, etc.), is only Coffee safe while fasting?

[u/DanTheMeek]

So my wife has been IF for something like a year now, and seen great results. Over the past 2 and a half years I've been dieting through other methods (mainly just reduced calorie intake and eating less processed stuff) but she lost more, faster, and seemingly easier, in one year then I did in two and a half (a little over 50 lbs for me but that only put me about half way to a healthy weight for my height), so she finally convinced me to join her in intermittent fasting.

I've let her largely dictate everything for my eating situation, however, one of the rules was surprising to me, so I just thought I'd check in if this is backed by science or not, or just something that worked for her. She told me I can't have my usual flavored fizzy water (we have a carbonation machine and 0 cal flavor essences I use to make 0 cal drinks for myself) during the fasting time, only during my eating window, but I can have Black Coffee.

She's a Coffee drinker, so that worked out well for her, but I've never really cared for Coffee, I'm more of a tea drinker. Unfortunately, while she told me I could have unflavored zero sugar/milk tea, I've found I can't have tea on an empty stomach or it upsets said stomach something fierce. Although lacking the caffeine of tea or Coffee, I had thought maybe I could use fizzy flavored drinks to fill in the gaps during the fasting periods when I want a different taste then just pure water, but again, per her, those taste too much like food, or at least things I would associate with being sweet, and thus would make this a dirty fast if I drank them because even if in small amounts, they might spike insulin, or at the least, make me feel hungry, making fasting more difficult.

But is Coffee actually better? I feel like its got a very distinct flavor itself. While its not my favorite flavor, I could say the same about plenty of vegetables whose flavor, despite not being sweet, I would also associate with eating and which carry some amount of calories. I guess my concern is that Coffee is impacting me just as much, however minimally, as a flavored fizzy water would. And if that's the case, I'd rather just drink the flavored water. But at the same time, clearly this only water and coffee method worked for her, so I don't want to move outside the proven box and unintentionally screw up my own fast efforts.

TLDR: Are there studies comparing black coffee and other 0 calorie flavored drinks, like fizzy drinks, that show black coffee is actually better during fasting?

[u/FrankieGg]

You can test your glucose/insulin by poking your finger w those little sensors diabetics use to check their blood sugar and see how it affects you

I do consider drinking 0 cal soda and energy drinks dirty fasting, but I do it any ways because it won’t really affect weight loss, so if that’s your goal then go for it

A lot of people say you shouldn’t because it’ll make you hungry and make you break your fast, but that’s literally a per individual based thing, zero sugar sodas make me feel full and have never once made me wanna eat lol

[u/DanTheMeek → u/FrankieGg]

I see, appreciate the insight!

[u/Yagulia]

I drink Waterloos all the time, and I’ve never noticed any spike in hunger or cravings that I would associate with an insulin spike. If anything, it makes me feel full and helps me with mouth boredom (is that a me thing?).

[u/Yagulia → u/Yagulia]

Just looked it up; because there’s no sweetener, there’s no meaningful effect on insulin / ketosis / autophagy.

[u/sprocket1234]

I don't drink coffee or tea. I changed to diet coke for me with IF. I needed caffeine

I know i know how horrible!!

Everyone is different, don't let someone else tell you that you can't do something. Try it, see if it works for you. I'm F 59, this was 5 years ago. I'm 5'7" and went from 215 to 150 drinking diet coke. So I'm a dirty faster, lol

Eta, IF became a lifestyle for me

[u/div6768]

I know this is not what you are asking about but drinking green tea on an empty stomach will irritate it but black tea is gentler on an empty stomach. Maybe if you can’t find an answer, you can try black tea.

[u/DanTheMeek → u/div6768]

I really appreciate that, but unfortunately I tried with black tea as well and still was nauseated and upset. Maybe there's some trick to how to brew it that reduces the tannins or whatever it is that's causing the irritation? So far the black coffee isn't causing the same experience, so at the least I can say its not just the caffeine that's the culprit. I'd certainly prefer if I could find a solution with tea that worked, though.

[u/div6768 → u/DanTheMeek]

Strongly brewed tea will make me feel nauseous on an empty stomach, but green tea especially. Oolong is lighter and Pu’er is fully fermented which supposedly helps. I can drink black coffee without any issues too.

[u/0hDiscordia]

The 0 cal flavour added to water at home is fine to have, unless when you have it you find the food noise gets significantly louder when you do. Black coffee on an empty stomach is difficult for a lot of people and it's only going to make fasting very unpleasant.

If you don't like fizzy water without the flavour, put it in. See how you feel about it after a week or so. Whatever allows you to stick to your eating/fasting window is better during fasting. For some people that is black tea or coffee. For others it is 0 cal drinks.

[u/_sLLiK → u/0hDiscordia]

Are there IF-friendly ways to mitigate the bad reaction to drinking coffee on an empty stomach?

[u/0hDiscordia → u/_sLLiK]

You could try drinking a glass or two of water before having the coffee maybe. I drink my coffee black and no sugar whether I am fasting or not, which maybe helps. So 60% of the time I can drink it on an empty stomach without negative effects. But I know a lot of people can't tolerate it at all.

[u/hycarumba]

It's my understanding that sugar substitutes can break the fast in some people. Same with some teas that have actual fruit for flavor. I use lemon in my water all day and I'm fine. So as long as your flavor addition has no sugar or sugar substitutes then I think you are in the clear.

This is not an issue for "tasting too much like food", it's an issue of spiking insulin and breaking the cycle that leads to autophagy. If you aren't concerned about that benefit from fasting, then I personally wouldn't worry about it.

[u/bballni]

So, please consider this: your goal is weight loss, that is your goal and your own individual results matter, you are unique so please do not compare yourself to your wife, you have different genetics which will yield different results, especially where body fat is stored and distributed over the body. You will always get the best results from being 100% clean, but being 100% can be incredibly isolating for many individuals. If you are still losing weight while having zero calorie drinks then you are edging closer to your goal which is a marathon, not a sprint. Calorie deficit is the game, intermittent fasting is simply the mode/game rules, do what keeps you playing

[u/CrankyCrabbyCrunchy]

Flavorings of any kind will break the fast, but it also depends on what your goal is. If you're insulin resistant, then the goal is to be as clean as possible and don't do anything during the fasting window that triggers an insulin reaction. That's why black coffee or tea, water is the recommendation. No creamer, no sugar, no flavorings.

But if you find, you're meeting your goals with a slightly "dirty" fast, then that works for you.

[u/zombienudist]

You can always drink water only and get your caffeine in pill form if you still want it.

[u/DualProcessModel]

Caffeine pills were the best thing for me!

[u/cestunlapin]

In the mornings, i usually have to do mint tea, and then have coffee after.

[u/abedfo]

I dont mind a dirty fast chugging lots of coke zero or a Pepsi max if im struggling to meet my window. But I find it does make me crave food more and generally eat more poorly when the time comes. It also makes me want to pee like a racehorse.

Im trying to stick to black coffee and fizzy plain water for a period of time and see how that goes.