Amy Tenderich was diagnosed with type 1 diabetes in May of 2003. She is the founder and editor-in-chief of Diabetes Mine and co-authored the book Know Your Numbers, Outlive Your Diabetes. You will frequently find her speaking at diabetes, health, and social media events across the country.
The best times to check your blood glucose (BG) depends on your reasons for checking. If you are checking in order to choose your insulin doses, then the best times are:
1. At wake time in the morning
2. Before and after each meal
3. At bedtime
If you do not need the information immediately to set insulin doses but are checking for more “general purposes”—like to evaluate changes or improvement in your overall BG control—then checking at the same times each day is most helpful. This helps you identify trends, like if you are consistently high every day in the late afternoon. Of course, you’ll only see these trends if you keep track of your test results.
It’s important to use the little log book that comes with your meter to keep track of your numbers and look over them periodically. The data is not just for your doctor. It's for you.
As a rule of thumb, just before a meal and then three or four hours after provides a useful timeframe for seeing the effects of that meal. Similarly, testing before and just after exercise will tell you the effects of that particular activity.
If you routinely test before and after meals, before and after exercise, and before and after sleeping, you'll have great results to review yourself or with your doctor. These numbers will give you a good sense of what might be pushing your blood glucose up or down.
BONUS TIP: I recommend trying the “before and after” approach called Glucose Testing in Pairs. You will learn about a special logging booklet created by Roche Diabetes that patients can download for free.