by Frank
(Conshocken, PA)
QUESTION: I was recently diagnosed with type 2 diabetes. My original results were 128 mg/dL and HbA1c 7.3%. From March 2 to May 11, 2015, I lost 35.5 pounds. This morning my fasting glucose was 102 mg/dL, but after two cups of coffee with Splenda it rose to 117 mg/dL. Is this normal even though I had only liquid and no food?
A rise from 102 to 117 mg/dL after coffee is small and, by itself, is not concerning. For many nonpregnant adults with diabetes, a common premeal glucose target is 80–130 mg/dL, although personal targets vary.
Coffee can affect glucose even without food. Caffeine may temporarily raise or lower blood sugar in some people with diabetes by affecting insulin action. Morning hormones, normal day-to-day variation, and home-meter variation can also contribute.
Your earlier HbA1c of 7.3% was in the diabetes range. The improvement in your home readings is encouraging, but it does not mean the diabetes diagnosis has disappeared. A repeat HbA1c is more useful for judging your overall progress.
Answer by Dr. Albana Greca, MD, MMedSc
Hi Frank,
I would not be alarmed by a change from 102 to 117 mg/dL after two cups of coffee. That is a modest difference, and both numbers fall within the usual premeal target range used for many adults with diabetes.
| Result | Meaning |
|---|---|
| Fasting 102 mg/dL | Within the usual premeal target for many adults with diabetes |
| 117 mg/dL after coffee | Small rise; still within that usual target range |
| HbA1c 7.3% | Above the usual A1c goal for many adults and in the diagnostic diabetes range |
Your original fasting glucose of 128 mg/dL was also in the diabetes range if it was a properly performed laboratory fasting test and confirmed as required. Your HbA1c of 7.3% provides additional evidence that your glucose had been elevated over the preceding months.
Yes. Coffee itself contains very little carbohydrate when taken without milk or sugar, but caffeine can affect glucose differently from person to person. In some people with type 2 diabetes, caffeine can temporarily reduce insulin sensitivity and cause glucose to rise.
Morning hormones may also contribute. The body naturally releases hormones before and after waking that can encourage the liver to release glucose. This is related to the morning rise in blood sugar seen in some people with diabetes.
Splenda packets contain sucralose with very small amounts of carbohydrate-containing ingredients such as dextrose or maltodextrin. In ordinary amounts, this small carbohydrate load is unlikely to explain a major glucose increase.
If you want to see what affects you personally, compare your glucose on several similar mornings with plain coffee, decaffeinated coffee, and your usual coffee with Splenda. Do not draw conclusions from one reading alone.
For many nonpregnant adults with diabetes, common glucose goals are:
| Timing | Common target* |
|---|---|
| Before meals | 80–130 mg/dL |
| Peak after meals | Below 180 mg/dL |
| HbA1c | Below 7% |
*Targets should be individualized with your healthcare professional.
So 117 mg/dL is not a concerning number by itself. The more useful question is whether your glucose pattern and HbA1c are improving over time. A blood sugar level chart can help you compare readings taken at different times.
If the weight loss was intentional and achieved through a healthier eating pattern and safe physical activity, it may improve insulin sensitivity and help explain your lower glucose readings.
However, 35.5 pounds in about 10 weeks is substantial. If you did not intend to lose this much weight, or if you have weakness, excessive thirst, frequent urination, loss of appetite, or other symptoms, discuss the weight loss promptly with your doctor.
Frank, the change from 102 to 117 mg/dL after coffee is modest and does not suggest that something is going wrong. Caffeine, morning hormones, and ordinary glucose variation can all contribute.
Your lower readings may reflect the positive effects of your weight loss and other lifestyle changes, but the best measure of longer-term improvement will be your next HbA1c. Keep looking at the overall pattern rather than a single reading.
Medical review: Dr. Ruden Cakoni, MD, Endocrinologist
Last reviewed: August 2026.
Educational safety note: This answer is for general diabetes education only and does not replace personal medical advice. Do not start, stop, or change diabetes medicines, supplements, diet, or exercise plans without discussing them with your healthcare provider.
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