Can you have coffee while intermittent fasting? What you can and can't drink

• Yes, you can drink plain, black coffee while intermittent fasting - but no cream or sugar.
• Most calorie-free drinks are safe to consume during intermittent fasting.
• But some dietitians don't recommend diet drinks with artificial sweeteners.

If you're worried that morning fasting will interfere with your cup of coffee, we have good and bad news.

"You can have coffee," says Sue Ryskamp, senior dietitian at Michigan Medicine's Frankel Cardiovascular Center. "But you can't put anything in your coffee. It has to be black. No sugar or cream."

Coffee isn't the only beverage you can have during your fast. Here's what Ryskamp recommends you can and cannot consume while fasting intermittently.

You can drink no-cal fluids when intermittent fasting

During your fasting window, it's no-cal drinks only, says Ryskamp. That includes regular or flavored water and unsweetened and herbal teas.

In fact, Ryskamp encourages people to drink some fluids during their fast in order to stay hydrated.

However, Ryskamp discourages diet soft drinks or anything else with an artificial sweetener, even though they're calorie-free. "I don't promote those because I don't like anything artificial," she says.

Researchers have also found that artificial sweeteners might make you crave sugar, which isn't ideal when you have to wait for many hours before you can eat.

Caffeine, on the other hand, like in coffee, might actually help you stave off hunger pangs by suppressing your appetite.

Note: If you have high blood pressure, check with your doctor about coffee consumption. Caffeinated beverages can cause your blood pressure to spike, which might be worth monitoring for people with elevated blood pressure.

One exception to the rule

There is an exception to the no-cal rule while intermittent fasting. If you prefer your coffee with cream and sugar, that's still on the menu with the 5:2 intermittent fasting method. The reason has to do with how you restrict your caloric intake.

The 5:2 method differs from the 16:8 method, where you're only supposed to consume calories during a certain period of time each day. The 5:2 method, however, doesn't restrict you to a certain time period. Rather, it restricts how many calories you consume for certain days of the week.

The 5:2 intermittent fasting method means that five days out of the week you consume a recommended amount of calories for your height, weight, age, and sex. But for two, nonconsecutive days of the week you cut your caloric intake down to about 20% to 25% of your recommended amount.

Therefore, you can consume whatever you like on the 5:2 method - including a cappuccino at 8 am, if so choose. You just have to be aware of how that will count toward your total caloric intake on those two restrictive days.

Insider's takeaway

Regardless of the various forms of intermittent fasting - including alternate-day fasting, 5:2 fasting, and 16-hour fasting - the goal is basically the same. By limiting the number of hours in which you allow yourself to eat, you're also limiting the number of calories you consume.

That means during the fasting period, you're not taking in any calories, which is why drinking no-cal fluids, like coffee, tea, and water, is OK as long as it contains no caloric additives like sugar or cream.