Before changing the way you eat and altering your diet in any significant way, please speak with a health professional to make sure it’s the best decision for you.

We’re all familiar with the Roadrunner-level energy bursts that accompany that all-conquering morning cuppa joe.

Although intermittent fasting (IF) has its benefits, going without food or drink for hours on end is serious business.

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It’s natural for anyone lagging in the middle of a fast to wonder whether coffee is “allowed” or if it will undo all their hard work. Spoiler alert: A black coffee is fine, but you can’t just go loading up on mochas.

Or what about green tea or just a tiny snack? Here’s the truth about what will and won’t break the fast.

Short answer: Yes! Good news, right? Don’t go running to your local foam parlor just yet — it’s not that simple.

First, let’s define coffee. Any aficionados will know that there’s a myriad more on offer than a simple cup of dark roast.

The part you won’t like: A double mocha cappuccino with whipped cream and sprinkles does not qualify. Neither does a latte with 8 ounces of milk. While fasting, coffee is coffee with nothing in it.

So, yes, drinking black coffee during most types of intermittent fasting is totally OK. The popular 16:8 Leangains protocol (fasting 16 hours and eating during the 8-hour window) actually goes so far as to say that coffee with “a splash of milk” is acceptable in the fasted state (ooh, spoil yourselves, why don’t you).

With just 4.8 calories per medium brewed coffee, it makes sense that a cup of coffee won’t do much damage to your metabolism or blood sugar.

Coffee may actually help you speed up weight loss, according to recent research.Bakuradze T, et al. (2011). Antioxidant-rich coffee reduces DNA damage, elevates glutathione status and contributes to weight control: results from an intervention study. You may have to get used to the taste of black coffee (with a splash of milk if you’re feeling like a monarch), but we have faith in you.

Here’s our guide to brewing coffee the right way.

Here’s a list that gets the green light during the fasting phase, according to some IF experts.

Lemon water

Drinking water is not only permitted by the overlord of IF, but it’s also encouraged (shocking, we know).

Although your body can go for periods of time without food, it cannot function properly without water. Good old H2O is necessary for organ and muscle function, so be sure to pump your body full of it.Popkin BM, et al. (2011). Water, hydration, and health.

Thirst and hunger are easy to confuse with each other. Very often, drinking some water will rid you of what you thought were hunger pangs, as they’re simply your body telling you it would quite like some water, now, please.

Since water can get a little boring, add a squeeze of lemon. You won’t be adding a number of calories that will have any effect on your IF, and you’ll be able to add a new flavor without resorting to other drinks that are off-limits.

We’re big on infused water — here are some recipes we love.

Iced tea

Just like coffee, iced tea isn’t always as innocent as it seems. And the notion of picking a tea isn’t that easy either.

You’ve got sweet tea, tea and fruit “refreshers,” peach tea, green tea, matcha tea… the list goes on. However, most tea drinks contain additives, like sugar or milk, and these are a firm no-no during the fasting phase.

Help, however, is at hand, and it’s cool AF — literally. A medium mug of unsweetened, brewed ice tea provides only 4.95 calories and won’t even slightly dent your fast, let alone break it.

Your best bet is to try and brew your own from a simple black, green, or herbal tea bag. Alternatively, it’s best to look for brands that offer unsweetened varieties without any additives.

Here’s how to brew the best cup of tea imaginable.


Have you ever gone through the following thought process:

  1. “Gosh, my mouth tastes like I’ve been sucking on the exhaust pipe of a Buick.”
  2. “Aah! A pack of gum! I cannot wait to embrace the minty freshness and not taste the exhaust pipe of a Buick.”
  3. “Oh no! My eating regimen! Ack! Spit it out!”

There’s no need to freak out. Manufacturers make most gums using sugar alcohols, which means they’re low calorie (although the calorie content of sugar alcohols varies depending on the type of sugar alcohol), and they’re perfectly fine to have while in the fasting phase.

Some research even suggests that gum may decrease feelings of hunger. Time to stock up on some minty freshness!Melanson KJ, et al. (2017). Chewing gum decreases energy intake at lunch following a controlled breakfast.

It’s fine on a diet, but does gum reduce anxiety? We chewed on the research.

Some food and drink seems unassuming until it starts adding to your calorie count and effing with your eating regimen.

Green juice

While green juices are often marketed as a “cleanse” or a way to “detox,” that doesn’t mean they work that way or have a place in the IF lifestyle.

As a matter of fact, one of the benefits of IF is reducing insulin spikes and creating greater insulin sensitivity. Green juices undoubtedly contain calories and natural sugars, both of which will spike your blood sugar.

Don’t buy into the claims on the packaging. Dodge green juice during your fasting period.


Obviously, all foods are off-limits during the fasting stage, but your hungry stomach may convince your brain that certain low-cal snacks won’t really do any harm.

One 7-inch celery stick (no jokes, please) will add 6.4 calories to your daily tally. Doesn’t seem like much, does it? But if your hungry fasting brain starts chowing down on these, you could end up with a disrupted fast. And why undo your hard work?

The general fasting guidelines vary from plan to plan, but most only allow for zero-calorie drinks during fasting.

Celery consists of water and natural sugar. Rather than undoing all your hard work for some measly celery, wait until the eating hours and chow down on something you actually enjoy.

There’s a lot of unsupported hype around celery in weight loss circles… case in point: celery juice.

Believe it or not, the Leangains protocol says it’s OK to drink diet soda while fasting. Yes, diet soda. What is this heresy?

Other IF plans call for “clean eating” with a complete ban on processed foods. Diet soda is about as processed as these trap vocals.

Let’s put diet soda in the “maybe” column. One every now and then won’t kill you or mess with your diet too much.

We think that the safest option is to stick with water, coffee, or tea while intermittent fasting. Diet soda is acceptable on some diets, but it’s a big if for people on IF. Moderation is key.

You’re not supposed to feel crappy on IF — it’s meant to improve your life. You might dip in energy during fasting hours, so a cheeky coffee or tea is not going to upend your fasting progress.

In fact, it might give you the energy boost you need to keep your IF regimen sustainable.