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

Coffee may cause blood sugar to spike or fall. The effects depend on your metabolism, whether you drink it with food, and how much caffeine you consume.

Does Coffee Raise Blood Sugar Levels?

It can. But it depends on the dose, your individual biology, and how and when you drink it.

Drinking coffee may lead to short-term spikes in blood sugar and changes in insulin response, especially in people with insulin resistance, prediabetes, or type 2 diabetes.

Caffeine is likely the reason for this effect. It stimulates the release of stress hormones like adrenaline, which can interfere with insulin production.

It also signals the liver to release stored glucose, making it harder for cells to absorb this excess glucose from the bloodstream.

Do Other Factors Make a Difference?

Take note of whether you typically drink your coffee on an empty or full stomach. “Caffeine absorption rates are faster on an empty stomach,” said Candace Pumper, MS, RD, a registered dietitian at The Ohio State University Wexner Medical Center.

She added that rapid absorption can lead to more pronounced blood sugar spikes, especially if coffee is also loaded with added sugar or sweetened creamers. However, these effects are usually short-lived.

“The long-term observational cohort studies generally show a strong inverse association between higher coffee intake and risk of type 2 diabetes,” said Andrew Odegaard, MPH, PhD, associate professor and expert on diet, nutrition, and type 2 diabetes at UC Irvine Joe C. Wen School of Population & Public Health.

In other words, drinking more coffee tends to correlate with a lower risk for type 2 diabetes.

This may be because coffee contains other compounds with antioxidant and anti-inflammatory properties that may counterbalance caffeine’s downsides over time.

How to Avoid Blood Sugar Spikes from Coffee

If you’re concerned about your glucose response but don’t want to give up your brew, there are science-backed ways to sip smarter, according to Pumper and Odegaard:

• Drink coffee with or after food: Pair your brew with a meal or snack to slow caffeine absorption and blunt blood sugar spikes.
• Choose unsweetened or naturally sweetened options: Use natural sugar substitutes like stevia, monk fruit, or allulose instead of sugar or flavored syrups.
• Go half-caf or decaf: Cut back on the caffeine content if you’re especially sensitive to it or already have insulin resistance.
• Try coffee alternatives: Black or green tea, dandelion root coffee, or even low-acid coffee may be gentler on blood sugar.
• Track your response: Pay attention to how you feel when drinking coffee. If you wear a continuous glucose monitor, you can also track how different types and timings of coffee affect you. Stick with whatever timing leaves you feeling at your best.