Water is often overlooked when it comes to managing blood sugar and A1C levels. But proper hydration is far more powerful than many realize. Staying hydrated helps your body regulate blood glucose more efficiently and supports overall metabolic function. In fact, dehydration can spike blood sugar and make it harder to reach your A1C goals.
Your blood is about 83% water. When you don’t drink enough fluids, your blood becomes more concentrated. This causes glucose concentrations to rise, even if your sugar intake hasn’t changed. Hydration helps flush excess sugar out of your bloodstream via the kidneys, supporting healthy glucose balance.
Chronic mild dehydration may lead to consistently higher blood sugar, which over time raises your A1C. A dehydrated body signals stress, which releases hormones like cortisol — and cortisol can increase insulin resistance. Over time, this creates a cycle that’s hard to break without improving water intake.
While individual needs vary, a good starting point is the classic “8x8 rule” — eight 8-ounce glasses of water per day (about 2 liters). You may need more if you:
Your kidneys play a vital role in filtering glucose from the blood. Staying hydrated allows them to do this efficiently. If you’re dehydrated, your kidneys may retain water — which reduces glucose elimination and contributes to spikes in blood sugar.
Drinking more water may help reduce appetite and prevent overeating. Many times, we confuse thirst with hunger. Drinking water before meals can help reduce overall calorie intake — which supports weight loss and A1C improvement.
It’s easy to underestimate how much hydration affects blood sugar control. But drinking enough water is one of the simplest ways to support lower A1C levels and better energy. Make hydration a daily habit, and your body — and your glucose meter — will thank you.