So, you have type 2 diabetes. You’re not on insulin. You’re taking two or three oral medications. You feel fine most of the time. “Why bother checking blood sugars?” you ask. Good question.

The view on the importance of checking blood sugars has evolved over the years. In the past, self-monitoring of blood glucose (often referred to as SMBG) was recommended to be done at least three times a day in patients not on insulin.

Over the years, a shift has occurred and the recommended frequency is much less, but is still considered an important part of the routine of a life with diabetes. Part of this shift happened in 2000 when a scientific review article showed that SMBG did not make a difference in A1C, meaning that those who checked more often did not have better control than those who didn’t check.

So what’s the point? After all, it’s expensive, time consuming, and it hurts! This left the medical profession, patients, and even insurance companies wondering if this was a valuable task or not.

After the dust settled a bit from being stirred up by that article, most health care professionals agree that there is value in SMBG. So even though you feel fine most of the time, there are some things you can learn from that number staring back at you on your glucometer. The frequency and timing of checking aren’t nearly as important as what you do with the information.

No matter when you check blood sugar, I strongly urge you to keep a log sheet and write the numbers down. Yes, I am aware that your meter has a memory and that you can scroll through and look at the numbers anytime. That’s nice. Write down your numbers! It helps to see them all at once, in their columns of time of day and pre- or post-meal. You know what is very likely the most important column on that log sheet? The comment column! That’s the place for you to honestly write what might be contributing to that low or high number.

  • Did you eat a huge bowl of fruit without any protein to go with it? That’s useful information!
  • Did you go for an intense walk? That’s useful information!
  • Did you skip a meal? That’s useful information!
  • Are you feeling crummy today? That’s useful information!
  • Did you skip a few doses of metformin? That’s useful information!

The more connections you can make between your glucose number and what may have caused it, the better you will become at managing your diabetes. There is no limit to the number of factors that can make blood sugar swing between highs and lows.

The greatest benefit from SMBG is the way it helps you connect your behaviors or actions with the number you see. You can use this information to make all kinds of decisions that can lead to better overall control. It’s not even just writing down numbers that makes a difference. It’s the way you use the information.

So really, when is the best time to check blood sugar?

There’s no one best time. Of course, it’s always important to check when you feel symptoms of lows –shaky, nausea, headache, weakness, etc. We want to be sure to treat any true hypoglycemic values (blood sugar less than 60).

For people not taking insulin, most insurance companies only pay for one test strip per day. If that is your situation, I recommend varying the time of day that you check. Here’s a sample schedule:

Monday morning – fasting

Tuesday – just before lunch and 2 hours after lunch (if you can use 2 strips)

Wednesday – just before dinner

Thursday – 2 hours after dinner

Friday – at bedtime

Saturday – fasting

Sunday – 2 hours after any meal

Fasting numbers are nice to know, but there’s more value in the 2-hour post-meal (also called post-prandial) number. This is the reading we take 2 hours after the start of a meal. It’s what tells us how your body handles a load of carbs. Lots of times, that post-meal value is what is making your A1C higher than expected.

Remember, checking only once a day applies to those not on insulin. If you are taking insulin, your schedule will be more frequent, and for good reason. If you are able to check twice a day, doing that just before a meal and 2 hours after that same meal will give you the most useful information.

The best thing you can do with blood sugar readings is write them down. Make a guess as to why you think that value is what it is. Change your behavior based on what you learn.

What are your biggest frustrations with blood glucose monitoring? What are your tips for staying on track with checking? Let us know in the comments!

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