Intermittent fasting [1], commonly referred to as IF, has become all the rage lately, and it doesn't look like the trend is going away anytime soon. The practice of intermittent fasting [2], or time-restricted feeding, is when a person limits the period of time in which they consume calories down to a limited number of hours. So for example, I practice IF with an eight-hour eating window, which means that I will only eat between the hours of 12 p.m. and 8 p.m.

People fast for so many reasons; some fast because they're trying to lose weight while others fast to improve medical conditions such as diabetes and high blood pressure. The science behind intermittent fasting has slowly been piling up, too, with research showing that participants of intermittent fasting experience a reduction in weight [3] and inflammation and improvement in insulin sensitivities.

Harvard-trained physician and author of The Paleovedic Diet, Dr. Akil Palanisamy [4] further explains to POPSUGAR that "autophagy is the self-cleaning process by which the body's cells break down and recycle damaged proteins and components. This is activated by intermittent fasting, but anything other than water (even black coffee) disrupts it to some extent."

So does that mean you should abstain from your caffeine fix when fasting? According to Dr. Josh Axe, D.N.M., C.N.S., D.C., founder of DrAxe.com [5], bestselling author of Eat Dirt, and cofounder of Ancient Nutrition, tea and coffee are fine to consume as long as you don't add any milk or sweeteners. He explains on his blog, "If you're on a time-restricted fast and you're in no-eating hours, it's best to stick to no- or low-calorie drinks [6] like water, coffee, (with no milk) and tea. If you're on an alternate day diet or something similar, even during low calorie hours, you can technically drink whatever you'd like — but remember, this will count against your calories." Dr. Palanisamy also agrees that during fasting, the "appetite-suppressing effects of coffee are probably beneficial."

Now if you're not used to drinking your coffee black, don't despair. There are some no-sugar options that can help lighten and sweeten your morning cup of joe. If you're like me and can't fathom the idea of drinking black coffee, consider adding a few splashes of unsweetened almond [7] or coconut milk. Cutting out the sugar can be especially hard for some people, but there are sugar-free substitutes on the market, such as stevia [8], erythritol, or xylitol, that can serve as a great alternative. Another modification you can make in your coffee during IF is to consume bulletproof coffee [9]. Simply by adding high-quality grass-fed butter and MCT oil [10], you may find yourself having a much easier time abstaining from food [11].

Whichever option you choose, there's enough evidence to show that intermittent fasting has many health benefits. Dr. Palanisamy sums it up best by saying, "The final caveat is that some fasting is better than none. So if having a regular or even bulletproof coffee is the only way that you can stick with the practice of intermittent fasting, then it's probably worth it."