Intermittent fasting(IF) has some serious benefits.

A quick refresher: What is intermittent fasting?

Even a few calories' worth of food can inactivate some of fasting’s perks.

Stephanie Eckelkamp

This ultra-low-calorie territory is where things get a little tricky.

According to Horne, it likely needs to be a water-only fast to maintain themaximumbenefit from autophagy.

Others aren’t so sure we need to be quite this nitpicky, though.

Bindiya Gandhi, M.D.

“I’ve heard good debates about whethercoffee can break a fast.

“I would say if you’re drinking organic black coffeeno cream, no sweetenersthen you should be fine.

Some foods maintain many of fasting’s benefitswhile keeping you sane.

“I call this ‘dirty fasting,'” says Shah.

Integrative dietitianAli Miller, R.D., appreciates a more flexible approach as well.

Of course, not everything is on the table.

“Caffeine does have some benefits for fasting, such as appetite suppression.

Bonus: A little fat in the morning can also help keep those bowels regular.

The addition of a little fat to your fasting window may be even more important for certain women.

Bone broth

Another liquid that’s frequently touted as “acceptable” during a fast isbone broth.

So, if bone broth is the tool you gotta stick to your fast, keep using it.

“I’m not a fan of artificial sweeteners at all,” says Pedre.

“Just because something is noncaloric doesn’t mean it is free of metabolic influence,” says Miller.

And blood sugar drops, as we all know, can make us miserable and hangry.

Hardick, D.C.“Keeping a food journal can help ensure you’re eating enough of the right foods.