Intermittent fasting has been exploding in popularity over the past several years, and there are many new people beginning to experiment with intermittent fasting. So for those who are unaware about the rules of intermittent fasting, it basically consists of a window of time where you are restricting yourself from consuming calories, “fasting”. Technically, intermittent fasting should be called time restricted eating, because it is a time period where you are restricting yourself from eating. There are many different intermittent fasting protocols, the most popular being 16:8, 20:4, or 24hr alternate day fasts.
Obviously you cannot consume any food during the fasting window, because food contains calories which will break your fast. However, the main question that arises is what can you DRINK during the fasting window, because there are multiple beverages that contain zero calories. So technically, you are not consuming any calories with these beverages. However, there has been some debate on whether or not these drinks are acceptable, and whether or not these drinks “break” your fast.
I will be discussing the main beverages people enjoy while fasting, and whether or not these beverages are truly acceptable while fasting. The most popular drinks consumed while intermittent fasting are water, sparkling water, carbonated water, black coffee, black tea, green tea, BCAA’s, diet soda, sugar-free energy drinks, and any other zero calorie or sugar-free beverages out there.
1. Water (acceptable)
First on our list is good ole’ H20. You can’t go wrong with plain water while intermittent fasting. We all know how beneficial and important water is for our body to function properly, and stay hydrated. This is especially true while fasting, and I highly recommend to drink plenty of water while intermittent fasting. Water will ensure you stay hydrated while fasting, and will also help keep your appetite suppressed.
Some people add lemons, mint leaves, or other fruits to infuse their water for a better taste. I recommend not adding too much lemon or fruit into your water while fasting. Most likely a small piece of lemon in your water will not break your fast, but a lot of lemon or lemon juice could most definitely break your fast. This is due to lemon and other berries containing fructose which is a carbohydrate, and would trigger an insulin response.
2. Sparkling Water (acceptable)
Sparkling mineral water is a very popular drink people consume while intermittent fasting. Sparkling water is still providing hydration while also containing some carbonation. The carbonation can be quite helpful to suppress your appetite while you are fasting. That is what makes sparkling water such a popular choice while fasting.
Sparkling mineral water contains smaller amounts of carbonation compared to carbonated waters. Two of the most popular sparkling mineral waters people drink while fasting is San Pellegrino & Perrier. Other sparkling waters with a small hint of natural flavors are Bubly & LaCroix. Both of these contain zero calories, and no artificial sweeteners. Personally, I prefer to drink Topo Chico while fasting, because to me it taste the most crisp with a lot of carbonation. Check out my other article for the best sparkling waters to drink while fasting.
3. Carbonated Water (acceptable)
Carbonated water also known as “club soda” is slightly different than sparkling water due to the manufacturing process. Carbonated water gets it carbonation artificially from the addition of carbon dioxide to produce carbonic acid inside the water. Carbonated waters often contain a small amount of sodium as well, to neutralize the acidity. Club sodas such as Schweppes or Canada Dry are other options for those who like to have a carbonated/fizzy drink while intermittent fasting.
4. Black Coffee (acceptable)
Black coffee is super popular among those who participate in intermittent fasting. Those who enjoyed having coffee with cream/sugar before intermittent fasting have had to resort to drinking plain black coffee while fasting. It can be hard to give up your morning ritual of a Starbucks latte to just plain black coffee, but it is the price you pay to intermittent fast. Read my complete article on black coffee and fasting here.
The good thing is that black coffee will still provide you the caffeine boost in the morning, without breaking your fast. Black coffee, plain espresso, and black cold-brew are all acceptable options due to them containing zero calories. There are also some health benefits to drinking black coffee due to antioxidants found in coffee beans. Caffeine has been shown to increase the fat burning effects of fasting, while suppressing your appetite as well. Black coffee is a great choice while intermittent fasting.
Make sure it is plain black coffee, without any cream or sugar.
5. Black Tea (acceptable)
Another great option to sip on during your fasting window is black tea. Black tea provides a refreshing drink that you can drink in a greater quantity compared to black coffee. I sometimes will sip on a 32oz black iced tea while fasting, because it only provides about 200mg of caffeine. Whereas, 32oz of iced black coffee (400-500mg of caffeine) would make me too jittery. The good thing is black tea will provide you a decent amount of caffeine, without breaking your fast.
Similar to coffee, black tea provides some health benefits due to the antioxidants found in tea leaves. Tea leaves contain groups of polyphenols, including catechins and theaflavins, which are powerful antioxidants. The caffeine/antioxidants found in black tea can also help accelerate fat burning while fasting. So you can’t go wrong with a black iced tea, especially during a hot summer morning while fasting.
Make sure it is plain black tea, without flavoring or sugar.
6. Green Tea (acceptable)
Green tea is a popular option for those who are sensitive to caffeine, but still want to sip on something other than water. An Iced green tea only provides about 20-40mg of caffeine. The main benefit of green tea is the antioxidants found in green tea leaves. Green tea contains large amounts of Catechins, which is a strong antioxidant. Specifically, the Catechin found in green tea is called EGCG (Epigallocatechin Gallate). This antioxidant in green tea has been shown to reduce free radicals (protecting cells & preventing cellular damage).
Another reason green tea makes an excellent drink while fasting is due to the fat burning properties found in green tea. The EGCG found in green tea can boost your metabolic rate, thus increasing fat burning. You may be aware of this because green tea pills are often sold as a fat burning supplement.
Make sure it is plain green tea, without flavoring or sugar.
7. BCAA’s (technically not acceptable)
Branched chained amino acids are often consumed by those who workout to increase muscle repair/recovery following a workout. This is due to BCAA’s being the building blocks for protein. The problem with drinking BCAA’s while fasting is that it technically “breaks” your fast. This is due to do amino acids such as Leucine, which is the main amino acid responsible for activating protein synthesis.
Leucine is the main amino acid that is responsible for activating pathways of protein synthesis to your muscles. The problem is Leucine also activate similar pathways in the brain. Research has shown that Leucine activates these pathways in your brain, and will make your brain believe you are now fed. Your brain USES Leucine as an indicator for whether or not you have been fed.
So technically, if you drink BCAA’s while fasting, your brain will believe you have broken the fast. Even though you haven’t consumed calories, Leucine will trigger pathways which tell your brain you have been fed. Therefore, this would “turn off” the neurological benefits of intermittent fasting such as cellular autophagy, neuro-protective factors, and longevity. I recommend not drinking BCAA’s while fasting.
The main reason people like to consume branched chain amino acids (BCAA’s) while fasting is to prevent muscle breakdown (catabolism). Especially if you workout/lift weights while you are in a fasted state. I recommend lifting weights while you are in your feeding window to avoid this, but if you absolutely have to workout while in your fasting window, then you could consume amino acids during the workout (to avoid muscle breakdown). Technically, it will break your fast (at least neurologically), but you still will be getting the fat burning effects, and the effects from not eating.
Amino acids/supplements such as beta alanine, creatine, L-carnitine, and betaine do not break your fast. This is because these amino acids are not responsible for protein synthesis, unlike Leucine. Read my complete article about BCAA’s and intermittent fasting here.
8. Diet Soda (technically not acceptable)
Diet soda seems to be a popular drink people want to consume while intermittent fasting. Especially for those of you who are soda drinkers, I understand it can be very challenging not to consume soda during the day. Or maybe you were one who used to drink coffee with cream/sugar, and now that you started intermittent fasting you want to find an acceptable caffeine source to consume while fasting. Especially if you hate black coffee.
The ONLY problem with diet soda and intermittent fasting is the artificial sweeteners. If it wasn’t for the artificial sweeteners I would say 100% “Yes, you can consume diet soda while fasted”, but the artificial sweeteners make it a little trickier to answer.
The issue with the artificial sweeteners is that it can trick the brain into thinking you have been fed. This is due to the taste of sweetness signaling to your brain that you have been fed. This is very similar to the effects BCAA’s can have on your brain.
However, there is conflicting research on the true effects artificial sweeteners can have on the brain. Whether or not the artificial sweeteners on your tongue can trick your brain into believing you are now fed is still debatable. The fact that diet soda contains 0 calories, 0 carbs, 0 fats, 0 proteins still makes it a better choice than coffee with cream. Read my complete article about diet soda and intermittent fasting here.
9. Sugar-Free Energy Drinks (technically not acceptable)
Those of you who dislike black coffee or black tea, may be looking for another caffeine source while intermittent fasting. A popular choice is sugar-free energy drinks. There are definitely some good zero calorie energy drinks such as Monsters, Red Bull, Bangs, or Rockstars.
These contain a good amount of caffeine usually 200-300mg which can help boost metabolic rate and increase the fat burning effects while intermittent fasting. However, the only problem with sugar-free energy drinks is the artificial sweeteners. Like I mentioned about diet sodas, the issue with the artificial sweeteners is that it can trick the brain into thinking you have been fed. This is due to the taste of sweetness signaling to your brain that you have been fed.
Like I mentioned earlier there is conflicting research on the true effects artificial sweeteners can have on the brain. Whether or not the artificial sweeteners on your tongue can trick your brain into believing you are now fed is still debatable. However, as of right now I believe sugar-free energy drinks should be avoided while intermittent fasting. Read my complete article about sugar-free energy drinks and intermittent fasting here.
10. Broth (technically not acceptable)
Broth is a popular choice that many people consider consuming while intermittent fasting. However, broths contain a small amount of calories which would technically break your fast. Broth is made of water in which meat, vegetables, bones, or fish have been simmered in the water creating the savory flavor of broth. Some of these ingredients are absorbed while broth is made, which is why broth contains a small amount of calories.
Meat and bone broths usually contain around 30-40 calories per 8 oz serving with most of those calories being from fat. Vegetable broth contains no fat, but will still break your fast due to an 8oz serving containing around 12-15 calories.
TheMuscleMaster’s Final Say:
There are a lot of zero calorie/sugar-free drinks available on the market today, but not all of them are “technically” acceptable while intermittent fasting. Make sure to do your research, and try to avoid zero calorie drinks that contain artificial sweeteners, because they may break your fast.
I recommend sticking to the basics such as water, sparkling water, or black coffee/tea. I personally, will consume water immediately upon waking up, and then I will have a black iced coffee a few hours later. I have noticed that the black coffee really suppressed my appetite, and makes intermittent fasting effortless.
Also, I personally do not lift weights while fasting due to the catabolic effects it can have on my muscles. I will do some light cardio while fasted, but I hold off on the weight training until I am fed. This is because I do not want to consume my BCAA’s while I am fasted, due to amino acids like Leucine technically breaking my fast.