Understanding Blood Sugar Values

According to many doctors and dieticians blood sugar or BG* values fall into a couple of categories: diabetic, "good enough" for a diabetic and non-diabetic. I strongly believe that you shouldn't settle for "good enough" and that diabetic complications are reduced when your blood sugar values are kept in the non-diabetic range as much as possible.

* Often you will see BG or blood glucose instead of blood sugar. It means the same thing

When it comes to being diagnosed as diabetic, each type of blood sugar measurement will give you different information. The most commonly ordered test is the fasting blood sugar test, which is the LAST one to indicate that you have diabetes... Your post-prandial numbers are the FIRST to indicate that you have diabetes so of course doctors rarely use that measurement. Whether you testing for diabetes or you are trying to manage your blood sugar, don't just rely on the fasting!

Damage from high blood sugar can start at 140, so I always strive to keep my blood sugar under that at all times.


Fasting blood sugar is your blood sugar measurement when you first wake up in the morning. A fasting blood sugar greater than 100 is diabetic.

I aim for 75-95. Anything higher indicates to me that my liver is releasing stored glucose when I wake up (Dawn Phenomenon) and that I should review my food log for the past week to identify the culprit.

Post Prandial

Post prandial blood sugar is your blood sugar measurement after a meal. I want to stay under 140 because damage can occur at higher levels. Both the total value and the difference between your pre and post meal values are important. Read Monitoring your blood sugar for more information on testing after a meal.


The A1c test measures the amount of glycated hemoglobin in your blood or how much glucose is stuck to your red blood cells. It is an estimation* of how high your blood sugar levels have been for the past 2 months. Below are my interpretation of different A1c ranges. Don't let your doctor settle for a diabetic values. My goal is to control my blood sugar well enough that I am in the non-diabetic range.

A1c (%) Estimate blood sugar Level (mg/dl)
5 80
6 120
7 150
8 180
9 210
10 240
11 270
12 300
13 333
14 360

* The A1c is only an estimation and can be made less accurate by many variables.

What Affects Blood Sugar?

The #1 thing that raises your blood sugar is carbohydrates. Carbohydrates, "complex" or not, are turned into glucose by your body. So even if it doesn't taste sweet, think of it as sugar.

Fat, protein and fiber slow the digestion and will cause slower longer spikes. Carbohydrate heavy meals (like oatmeal or pancakes with syrup) will have a higher faster spike. Large spikes indicate that you ate more carbohydrates than your body can process in a timely fashion.


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