Susan B. Sloane, BS, RPh, CDE, has been a registered pharmacist for more than 20 years and a Certified Diabetes Educator for more than 15 years. Her two sons were diagnosed with diabetes, and since then, she has been dedicated to promoting wellness and optimal outcomes as a patient advocate, information expert, educator, and corporate partner.

So your doctor has asked you to keep track of your blood sugars, and you are testing…when you remember. You have a list that consists of random numbers: 70, 140, 210. 

But you're confused. You exercise, eat healthy, and yet can’t seem to reign in those numbers that, on the surface, make absolutely no sense to you. I totally understand. I have been there.

To fully utilize the information in your blood glucose monitor to your complete advantage, you need to log another piece of information with that number to give it meaning—the time you took the reading. It's also good to note if you just had a meal or snack. 

Now, if you want to get fancy, you can also write in if you were ill, had just exercised, or had taken new medication. This sounds overwhelming at first, but if your diary is accurate, you can learn how your body “reacts” to certain things like exercise, and in time, the detailed log will be a point of reference, but you will not need to write it all down all the time.

Understanding after-meal tests

Let's unravel the mystery by starting with the ever important post-prandial, or after-meal, blood glucose reading. This reading is taken one-and-a-half to two hours after you start eating a meal. The information in this number tells us a few important things. 

First, it tells us how the meal itself affected your blood glucose. If the meal was very high in carbs, like pizza or French fries, your post-prandial blood sugar will be elevated. If you ate a reasonable, healthier meal and your blood glucose is still elevated, your medication may need to be adjusted. 

There are certain medications that target post-prandial blood glucose specifically. These may include medications such as Byetta®, Januvia®, Onglyza®, and rapid-acting insulin such as Humalog® and Novolog®. If fasting blood glucose is within the normal range and you see post-prandial blood sugars rising, you may need to add or adjust these medications with the assistance of your healthcare team. 

Post-prandial spikes are often responsible for elevated A1cs, when fasting numbers are good. When you start to do your detective work, you can find the cause for elevated blood glucose and start to treat it. Exercise has an effect as well, and the effects of that exercise can linger well over 24 hours, leaving you with lower than average blood glucose readings.

“You are what you eat,” never rang so true. A person without diabetes never gets to see the effect that certain foods have on their body, until perhaps it is too late. Out of sight and out of mind, this person may continue eating fast food and sugars because they don’t see the direct harm these foods have on their bodies. People with diabetes have a window into exactly how bad foods react in our bodies. It’s not a bad thing; it actually keeps us honest about what we eat.