You can drink moderate amounts of black coffee during fasting periods, as it contains very few calories and is unlikely to break your fast. In fact, coffee may enhance the benefits of intermittent fasting, which include reduced inflammation and improved brain function.

Does black coffee affect autophagy?

Short-term administration of both regular coffee and decaffeinated coffee induces autophagy accompanied by a reduction in global acetylation levels of proteins in the liver.

Can you drink black coffee when fasting for blood work?

Can you drink coffee if you're fasting before a blood test? Even if you drink it black, coffee can interfere with blood test results. That's because it contains caffeine and soluble plant matter, which might skew your test results. Coffee is also a diuretic, which means that it will increase how much you pee.