What Happens to Your Blood Sugar When You Drink Coffee Every Day?

Coffee is one of the most widely consumed drinks in the world, but for people watching their blood sugar, it comes with a complicated relationship worth understanding.

The short answer is yes, coffee can raise blood sugar, but how much depends on the person, how the coffee is taken, and when.

Caffeine is largely responsible for the effect. It triggers the release of stress hormones like adrenaline, which can interfere with insulin production and prompt the liver to release stored glucose into the bloodstream, making it harder for cells to absorb the excess sugar.

The result can be a short-term spike in blood sugar, particularly in people with insulin resistance, prediabetes, or type 2 diabetes.

Drinking coffee on an empty stomach makes things worse. Candace Pumper, a registered dietitian at The Ohio State University Wexner Medical Center, says caffeine is absorbed faster without food, which can make blood sugar spikes more pronounced, especially when the coffee is loaded with added sugar or sweetened creamers.

However, the picture changes when you zoom out. Long-term studies consistently show that people who drink more coffee actually have a lower risk of developing type 2 diabetes. Researchers believe this is because coffee contains antioxidant and anti-inflammatory compounds that may offset caffeine’s short-term downsides over time.

Andrew Odegaard, an associate professor and diet and nutrition expert at UC Irvine, says the observational evidence pointing to coffee’s protective effect against type 2 diabetes is strong.

For those who want to keep drinking coffee without the blood sugar rollercoaster, experts recommend the following:

Drink coffee with or after a meal rather than on an empty stomach to slow down caffeine absorption. Swap added sugar and flavoured syrups for natural alternatives like stevia, monk fruit, or allulose. Consider cutting back on caffeine by going half-caf or switching to decaf if you are particularly sensitive. Alternatives like black tea, green tea, or dandelion root coffee may also be gentler on blood sugar levels.

If you wear a continuous glucose monitor, tracking how different types and timings of coffee affect your levels can help you find what works best for your body.